EP0492240A1 - Device to improve the silence ability of the exhaust flow of an internal combustion engine - Google Patents

Device to improve the silence ability of the exhaust flow of an internal combustion engine Download PDF

Info

Publication number
EP0492240A1
EP0492240A1 EP91121051A EP91121051A EP0492240A1 EP 0492240 A1 EP0492240 A1 EP 0492240A1 EP 91121051 A EP91121051 A EP 91121051A EP 91121051 A EP91121051 A EP 91121051A EP 0492240 A1 EP0492240 A1 EP 0492240A1
Authority
EP
European Patent Office
Prior art keywords
internal combustion
combustion engine
flow
exhaust gas
pulses
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP91121051A
Other languages
German (de)
French (fr)
Other versions
EP0492240B1 (en
Inventor
Siegfried Ing. Wörner (grad.)
Peter Dr. Ing. Zacke
Friedrich Dipl.-Ing. Schlenker
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eberspaecher Climate Control Systems GmbH and Co KG
Original Assignee
J Eberspaecher GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by J Eberspaecher GmbH and Co KG filed Critical J Eberspaecher GmbH and Co KG
Publication of EP0492240A1 publication Critical patent/EP0492240A1/en
Application granted granted Critical
Publication of EP0492240B1 publication Critical patent/EP0492240B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N1/00—Silencing apparatus characterised by method of silencing
    • F01N1/14—Silencing apparatus characterised by method of silencing by adding air to exhaust gases

Definitions

  • Piston internal combustion engines generate a pulsating exhaust gas flow, the sound pressure peaks of which have a frequency corresponding to the ignition frequency of the internal combustion engine.
  • Sound frequencies which, for example in the case of a four-cylinder engine, are in the range from 50 to 200 Hz and which are only attenuated to a limited extent with the customary silencers - if one uses a silencer size that is acceptable from the available installation space can.
  • the invention is concerned with the problem of achieving an improvement in the area of low sound frequencies of the exhaust gas stream leaving the internal combustion engine in such a way that the subsequent sound attenuation can take place more effectively than before even without unduly large silencers.
  • the invention relates to a method for improving the silenceability of the pulsating exhaust gas flow of a piston internal combustion engine, characterized in that flow pulses of a gas are supplied to the exhaust gas flow between the sound pressure peaks.
  • the invention further relates to a device for improving the silenceability of the pulsating exhaust gas flow of a piston internal combustion engine, characterized in that a device is connected to the exhaust gas line of the internal combustion engine, which supplies flow pulses of a gas to the exhaust gas flow between the sound pressure peaks.
  • the invention realizes the principle of placing flow impulses of an externally supplied gas, preferably air, between the sound pressure peaks of the exhaust gas flow generated by the internal combustion engine. This results in an exhaust gas flow downstream of the feed point of the flow impulses, which pulsates at a higher frequency than the exhaust gas flow leaving the internal combustion engine.
  • the exhaust gas flow resulting after the flow pulse supply or the periodic admixing of gas can therefore be effectively damped in the range of low speeds of the internal combustion engine with mufflers of common or even reduced size.
  • the muffler problems tackled according to the invention are naturally particularly pronounced in large-volume internal combustion engines with a relatively small number of cylinders, especially when they run under high load.
  • the essence of the invention is an artificial increase in the pulsation frequency of the exhaust gas flow, preferably a doubling of the pulsation frequency.
  • a particularly simple, preferred possibility is to provide a compressed gas storage unit, which of course needs to be continuously topped up, and to assign a valve, preferably a solenoid valve, which can be opened and closed with the required flow pulse supply frequency. Suitable servo valves are available on the market.
  • a valve preferably a solenoid valve
  • Suitable servo valves are available on the market.
  • the required matching of the flow impulses to be supplied according to frequency and phase position to the sound pressure peaks of the exhaust gas stream is particularly simple.
  • a corresponding, preferably electrical or electronic control can be done with average expertise to be created.
  • the control system can obtain the necessary information, for example, from the ignition system (Otto engine) or the injection pump (diesel engine) of the internal combustion engine.
  • trucks and buses in particular usually have a compressed gas storage or compressed air storage anyway, e.g. for brake actuation; this memory can be used with the appropriate modification for realizing the invention.
  • Another possibility is to provide a mechanical gas flow chopper for the gas to be supplied, which is coupled to the speed of the internal combustion engine.
  • the compressed gas for feeding the chopper can come from a compressed gas storage or from a compressor.
  • the chopper can be driven by the internal combustion engine or directly by the crankshaft of the internal combustion engine by means of a toothed belt, a chain, a gear transmission or the like. By coupling with the speed of the internal combustion engine, the frequency of the gas flow pulse supply is correct at all speeds of the internal combustion engine.
  • the chopper must be designed so that the phase position of the gas flow pulses to be supplied is correct.
  • Suitable choppers are known.
  • a basically suitable chopper of the latter type is described in DE-AS 1 447 993.
  • the mentioned choppers have in common that at certain relative positions between a rotatable part, which has at least one gas flow opening, and a stationary part, a gas flow pulse is released, while no gas flow pulse is released in between times.
  • the amplitude of the sound pressure peaks of the exhaust gas stream leaving the internal combustion engine varies with the current load state of the engine.
  • the amplitude of the supplied gas flow pulses is essentially constant and is somewhere, preferably in the middle range, of the amplitude of the sound pressure peaks.
  • the improvement effect according to the invention is most perfect in the medium load state of the engine, but is still pronounced even in the case of higher load states.
  • a load-dependent throttle or a load-dependent throttle valve is best suited for this.
  • the information required to control the throttle or the throttle valve can be derived in particular from the ignition electronics (Otto engine) or the injection pump control (diesel engine) of the engine, where the information about the current load state of the engine is present anyway.
  • the filling behavior of the cylinders of the internal combustion engine can also be influenced in a favorable sense by means of the invention. Because the opening times of the intake valve and exhaust valve of each cylinder of the internal combustion engine overlap, the filling behavior of the cylinders depends on the instantaneous exhaust gas back pressure in the exhaust pipe of the engine, this instantaneous exhaust gas back pressure being able to be influenced by the gas flow pulse feed according to the invention.
  • Air is particularly preferred as the gas to be supplied in the form of flow pulses.
  • FIG. 1 shows a four-cylinder engine 2 with the front area of its exhaust pipe 4. It is an Otto engine, the ignition of which is controlled by control electronics 6. Alternatively, it could be a diesel engine, in which case reference number 6 would represent the control component of the injection pump.
  • a silencer 8 is also shown, which sits a bit behind the engine 2 in the exhaust pipe 4. At least one further silencer is normally located further back in the exhaust pipe 4 and not shown.
  • a compressed air tank or pressure vessel 10 is continuously kept at a pressure of approximately 2 to 6 bar by an intermittently running compressor 12.
  • a line 14 leads from the pressure vessel 10 to an opening 16 into the exhaust gas line 4, the opening 16 being arranged between the engine 2 and the muffler 8.
  • a solenoid valve 18 and an electrically adjustable throttle 20 are seated one behind the other in line 14. Solenoid valve 18 and throttle 20 can also be combined to form an electrically operable throttle valve.
  • the solenoid valve 18 and the throttle 20 are electrically connected to the control electronics 6.
  • the sound pressure pulses 22 with sound pressure peaks 24 are drawn in with solid lines, as occur in the exhaust gas line 4 close behind the engine 2.
  • Each sound pressure pulse 22 is assigned to an extension stroke of a cylinder of the engine 2.
  • the time width and the mutual spacing of the sound pressure pulses 22 vary with the speed of the engine 2.
  • the amplitude 26 of the sound pressure peaks 24 varies with the load state (e.g. idling, half throttle, full throttle) of the engine 2.
  • the solenoid valve 18 is controlled such that a flow pulse 28 of compressed air from the pressure vessel 10 arrives at the mouth 16 between two sound pressure pulses 24.
  • Each flow pulse 28 supplied in this way has a time width such that it fits between two sound pressure pulses 22.
  • the time course of the flow pulses 28 does not exactly match the time course of the sound pressure pulses 22.
  • the solenoid valve 18 can be designed in such a way that a time course of the flow pulses 28 corresponding to the sound pressure pulses 22 results approximately.
  • the diagram in FIG. 2 shows the impulses at the junction 16.
  • a flow pulse of compressed air supplied from the outside is thus placed between two sound pressure pulses 22 originating from the motor 2.
  • the sound attenuation is considerably more perfect.
  • the annoying, low-frequency hum that is otherwise practically not easily dampened is significantly reduced.
  • the flow pulses 28 are shown with an amplitude 26 which corresponds to the amplitude of the sound pressure pulses 22.
  • the throttle 20 is provided. The throttle 20 is opened more strongly in the case of higher load states of the engine 2 and is closed more strongly in the case of lower load states of the engine 2.
  • a compressed air line 32 opens directly in front of the perforated disk 30.
  • the perforated disk 30 has a row of triangular through openings 34 distributed and spaced around the circumference.
  • a flow pulse line 36 begins just behind the perforated disk 30 and opens at the junction 16 into the exhaust gas line 4 of an internal combustion engine 2 (not shown in FIG. 3).
  • a compressed air flow pulse is supplied to the exhaust line 4.
  • the geometrical design of the passage openings 34 can influence the temporal pulse shape of the flow pulses 28.
  • a variable throttle can be provided in the compressed air line 32 or in the flow pulse line 36.
  • the drive of the perforated disk 30 is derived from the motor 2, so that there is a coupling with regard to frequency and phase position between the flow pulses 28 and the sound pressure pulses 22.
  • pulsator 38 which is one of several possible types of compressed air flow chopper.

Abstract

Process for improving the silenceability of the pulsating exhaust flow of a reciprocating-piston internal combustion engine (2), characterised in that flow pulses (28) of a gas are supplied to the exhaust flow between the acoustic pressure peaks (24). <IMAGE>

Description

Kolben-Verbrennungsmotoren erzeugen einen pulsierenden Abgasstrom, dessen Schalldruckspitzen eine der Zündfrequenz des Verbrennungsmotors entsprechende Frequenz haben. Bei relativ niedrigen Drehzahlen des Verbrennungsmotors ergeben sich Schallfrequenzen, die beispielsweise bei einem Vier-Zylinder-Motor im Bereich von 50 bis 200 Hz liegen und die mit den gebräuchlichen Schalldämpfern - wenn man eine vom verfügbaren Einbauraum her vertretbare Schalldämpfergröße zugrunde legt - nur begrenzt gedämpft werden können.Piston internal combustion engines generate a pulsating exhaust gas flow, the sound pressure peaks of which have a frequency corresponding to the ignition frequency of the internal combustion engine. At relatively low engine speeds, there are sound frequencies which, for example in the case of a four-cylinder engine, are in the range from 50 to 200 Hz and which are only attenuated to a limited extent with the customary silencers - if one uses a silencer size that is acceptable from the available installation space can.

Die Erfindung befaßt sich mit dem Problem, im Bereich niedriger Schallfrequenzen des den Verbrennungsmotor verlassenden Abgasstroms eine Verbesserung dahingehend zu erreichen, daß die nachgeordnete Schalldämpfung auch ohne ungebührend große Schalldämpfer effektiver als bisher erfolgen kann.The invention is concerned with the problem of achieving an improvement in the area of low sound frequencies of the exhaust gas stream leaving the internal combustion engine in such a way that the subsequent sound attenuation can take place more effectively than before even without unduly large silencers.

Gegenstand der Erfindung ist ein Verfahren zum Verbessern der Schalldämpfbarkeit des pulsierenden Abgasstroms eines Kolben-Verbrennungsmotors, dadurch gekennzeichnet, daß dem Abgasstrom zwischen den Schalldruckspitzen Strömungsimpulse eines Gases zugeführt werden.The invention relates to a method for improving the silenceability of the pulsating exhaust gas flow of a piston internal combustion engine, characterized in that flow pulses of a gas are supplied to the exhaust gas flow between the sound pressure peaks.

Gegenstand der Erfindung ist ferner eine Vorrichtung zum Verbessern der Schalldämpfbarkeit des pulsierenden Abgasstroms eines Kolben-Verbrennungsmotors, dadurch gekennzeichnet, daß an die Abgasleitung des Verbrennungsmotors eine Einrichtung angeschlossen ist, die dem Abgasstrom zwischen den Schalldruckspitzen Strömungsimpulse eines Gases zuführt.The invention further relates to a device for improving the silenceability of the pulsating exhaust gas flow of a piston internal combustion engine, characterized in that a device is connected to the exhaust gas line of the internal combustion engine, which supplies flow pulses of a gas to the exhaust gas flow between the sound pressure peaks.

Die Erfindung verwirklicht das Prinzip, zwischen die Schalldruckspitzen des vom Verbrennungsmotor erzeugten Abgasstroms Strömungsimpulse eines von außen zugeführten Gases, vorzugsweise Luft, zu setzen. Hierdurch ergibt sich stromab von der Zuführstelle der Strömungsimpulse ein Abgasstrom, der mit höherer Frequenz pulsiert als der den Verbrennungsmotor verlassende Abgasstrom. Der sich nach der Strömungsimpulszuführung bzw. der periodischen Zumischung von Gas ergebende Abgasstrom kann daher auch im Bereich niedriger Drehzahlen des Verbrennungsmotors mit Schalldämpfern gängiger oder sogar verringerter Größe wirksam gedämpft werden.The invention realizes the principle of placing flow impulses of an externally supplied gas, preferably air, between the sound pressure peaks of the exhaust gas flow generated by the internal combustion engine. This results in an exhaust gas flow downstream of the feed point of the flow impulses, which pulsates at a higher frequency than the exhaust gas flow leaving the internal combustion engine. The exhaust gas flow resulting after the flow pulse supply or the periodic admixing of gas can therefore be effectively damped in the range of low speeds of the internal combustion engine with mufflers of common or even reduced size.

Die erfindungsgemäß bekämpften Schalldämpferprobleme sind naturgemäß besonders ausgeprägt bei großvolumigen Verbrennungsmotoren mit relativ geringer Zylinderzahl, ganz besonders wenn diese unter hoher Last laufen.The muffler problems tackled according to the invention are naturally particularly pronounced in large-volume internal combustion engines with a relatively small number of cylinders, especially when they run under high load.

Erfindungsgemäß muß nicht jeweils zwischen zwei Schalldruckspitzen ein einziger Strömungsimpuls gesetzt werden, sondern man kann auch jeweils zwischen zwei Schalldruckspitzen des den Verbrennungsmotor verlassenden Abgasstroms mehrere Strömungsimpulse setzen. Kern der Erfindung ist eine künstliche Erhöhung der Pulsationsfrequenz des Abgasstroms, vorzugsweise eine Verdoppelung der Pulsationsfrequenz.According to the invention, it is not necessary to set a single flow pulse between two sound pressure peaks, but it is also possible to set a plurality of flow pulses between two sound pressure peaks of the exhaust gas stream leaving the internal combustion engine. The essence of the invention is an artificial increase in the pulsation frequency of the exhaust gas flow, preferably a doubling of the pulsation frequency.

Von der vorrichtungsmäßigen Verwirklichung her gibt es eine ganze Reihe von Möglichkeiten, die periodische Zuführung bzw. Zumischung von Gasströmungsimpulsen zu bewerkstelligen. Eine besonders einfache, bevorzugte Möglichkeit besteht darin, einen - naturgemäß laufend nachzuladenden - Druckgasspeicher vorzusehen und diesem ein Ventil, vorzugsweise ein Magnetventil, zuzuordnen, das mit der erforderlichen Strömungsimpulszuführfrequenz geöffnet und geschlossen werden kann. Geeignete Servoventile sind am Markt verfügbar. Bei dieser Lösung gestaltet sich die erforderliche Abstimmung der zuzuführenden Strömungsimpulse nach Frequenz und Phasenlage auf die Schalldruckspitzen des Abgasstroms besonders einfach. Eine entsprechende, vorzugsweise elektrische oder elektronische Steuerung kann mit durchschnittlichem Fachwissen erstellt werden. Die Steuerung kann die erforderlichen Informationen beispielsweise von der Zündanlage (Otto-Motor) oder der Einspritzpumpe (Diesel-Motor) des Verbrennungsmotors beziehen.In terms of the implementation of the device, there are a whole series of possibilities for the periodic supply or admixing of gas flow impulses. A particularly simple, preferred possibility is to provide a compressed gas storage unit, which of course needs to be continuously topped up, and to assign a valve, preferably a solenoid valve, which can be opened and closed with the required flow pulse supply frequency. Suitable servo valves are available on the market. With this solution, the required matching of the flow impulses to be supplied according to frequency and phase position to the sound pressure peaks of the exhaust gas stream is particularly simple. A corresponding, preferably electrical or electronic control can be done with average expertise to be created. The control system can obtain the necessary information, for example, from the ignition system (Otto engine) or the injection pump (diesel engine) of the internal combustion engine.

Es wird darauf hingewiesen, daß insbesondere Lastkraftwagen und Omnibusse üblicherweise sowieso über einen Druckgasspeicher bzw. Druckluftspeicher, z.B. für die Bremsbetätigung, verfügen; dieser Speicher kann mit entsprechender Modifizierung für die Verwirklichung der Erfindung herangezogen werden.It should be noted that trucks and buses in particular usually have a compressed gas storage or compressed air storage anyway, e.g. for brake actuation; this memory can be used with the appropriate modification for realizing the invention.

Eine weitere Möglichkeit ist das Vorsehen eines mit der Drehzahl des Verbrennungsmotors gekoppelten, mechanischen Gasstromzerhackers für das zuzuführende Gas. Das Druckgas zur Speisung des Zerhackers kann aus einem Druckgasspeicher oder von einem Kompressor stammen. Der Zerhakker kann mittels eines Zahnriemens, einer Kette, eines Zahnradgetriebes oder dergleichen von dem Verbrennungsmotor oder direkt von der Kurbelwelle des Verbrennungsmotors angetrieben sein. Durch die Kopplung mit der Drehzahl des Verbrennungsmotors stimmt die Frequenz der Gasströmungsimpulszuführung bei allen Drehzahlen des Verbrennungsmotors. Der Zerhacker muß konstruktiv so ausgelegt sein, daß auch die Phasenlage der zuzuführenden Gasströmungsimpulse stimmt.Another possibility is to provide a mechanical gas flow chopper for the gas to be supplied, which is coupled to the speed of the internal combustion engine. The compressed gas for feeding the chopper can come from a compressed gas storage or from a compressor. The chopper can be driven by the internal combustion engine or directly by the crankshaft of the internal combustion engine by means of a toothed belt, a chain, a gear transmission or the like. By coupling with the speed of the internal combustion engine, the frequency of the gas flow pulse supply is correct at all speeds of the internal combustion engine. The chopper must be designed so that the phase position of the gas flow pulses to be supplied is correct.

Geeignete Zerhacker sind bekannt. Insbesondere wird auf Drehschieber, rotierende Lochscheiben und Stator-Hohlrotor-Zerhacker, die Gasdurchtrittsöffnungen am Hohlrotor und am Stator aufweisen, hingewiesen. Ein grundsätzlich geeigneter Zerhacker des letztgenannten Typs ist in der DE-AS 1 447 993 beschrieben. Den genannten Zerhackern ist gemeinsam, daß bei bestimmten Relativstellungen zwischen einem drehbaren Teil, welches mindestens eine Gasdurchströmungsöffnung aufweist, und einem stationären Teil ein Gasströmungsimpuls abgesetzt wird, während in dazwischenliegenden Zeiten kein Gasströmungsimpuls abgesetzt wird.Suitable choppers are known. In particular, reference is made to rotary slide valves, rotating perforated disks and stator hollow rotor choppers which have gas through openings on the hollow rotor and on the stator. A basically suitable chopper of the latter type is described in DE-AS 1 447 993. The mentioned choppers have in common that at certain relative positions between a rotatable part, which has at least one gas flow opening, and a stationary part, a gas flow pulse is released, while no gas flow pulse is released in between times.

Ferner wird die Möglichkeit erwähnt, die erfindungsgemäß zuzuführenden Gasströmungsimpulse mittels eines Kolbens zu erzeugen, der in einem mit Einlaßventil und Auslaßventil versehenen Zylinder angetrieben hin und her bewegt wird. Der synchronisierte Antrieb des Kolbens wird am günstigsten von dem Verbrennungsmotor abgeleitet.Furthermore, the possibility is mentioned of generating the gas flow pulses to be supplied according to the invention by means of a piston which is driven in a cylinder provided with an inlet valve and an outlet valve and moved here. The synchronized drive of the piston is best derived from the internal combustion engine.

Die Amplitude der Schalldruckspitzen des den Verbrennungsmotor verlassenden Abgasstroms variiert mit dem momentanen Lastzustand des Motors. Bei einer einfachen Ausführungsform der Erfindung ist die Amplitude der zugeführten Gasströmungsimpulse im wesentlichen konstant und liegt irgendwo, vorzugsweise im mittleren Bereich, der Amplitude der Schalldruckspitzen. Bei dieser Ausführungsform ist der erfindungsgemäße Verbesserungseffekt bei mittlerem Lastzustand des Motors am perfektesten, aber auch bei höheren Lastzuständen noch ausgeprägt.The amplitude of the sound pressure peaks of the exhaust gas stream leaving the internal combustion engine varies with the current load state of the engine. In a simple embodiment of the invention, the amplitude of the supplied gas flow pulses is essentially constant and is somewhere, preferably in the middle range, of the amplitude of the sound pressure peaks. In this embodiment, the improvement effect according to the invention is most perfect in the medium load state of the engine, but is still pronounced even in the case of higher load states.

In Weiterbildung der Erfindung bevorzugt ist jedoch eine Ausführung, bei der die Amplitude der Strömungsimpulse in Abhängigkeit von dem Lastzustand des Verbrennungsmotors variiert wird, am besten im wesentlichen entsprechend der Variation der Schalldruckspitzen varriert wird. Vorrichtungsmäßig eignet sich hierfür am besten eine lastabhängig gesteuerte Drossel bzw. ein lastabhängig gesteuertes Drosselventil. Die erforderliche Information zur Steuerung der Drossel bzw. des Drosselventils kann insbesondere von der Zündelektronik (Otto-Motor) oder der Einspritzpumpensteuerung (Diesel-Motor) des Motors hergeleitet werden, wo die Information über den momentanen Lastzustand des Motors sowieso vorliegt.In a further development of the invention, however, an embodiment is preferred in which the amplitude of the flow pulses is varied as a function of the load state of the internal combustion engine, and is best varied essentially in accordance with the variation in the sound pressure peaks. In terms of the device, a load-dependent throttle or a load-dependent throttle valve is best suited for this. The information required to control the throttle or the throttle valve can be derived in particular from the ignition electronics (Otto engine) or the injection pump control (diesel engine) of the engine, where the information about the current load state of the engine is present anyway.

Es wird darauf hingewiesen, daß sich mittels der Erfindung auch das Füllungsverhalten der Zylinder des Verbrennungsmotors im günstigen Sinn beeinflussen läßt. Wegen der Überschneidung der Öffnungszeiten von Einlaßventil und Auslaßventil jedes Zylinders des Verbrennungsmotors hängt das Füllungsverhalten der Zylinder vom momentanen Abgasgegendruck in der Abgasleitung des Motors ab, wobei sich dieser momentane Abgasgegendruck durch die erfindungsgemäße Gasströmungsimpulszuführung beeinflussen läßt.It is pointed out that the filling behavior of the cylinders of the internal combustion engine can also be influenced in a favorable sense by means of the invention. Because the opening times of the intake valve and exhaust valve of each cylinder of the internal combustion engine overlap, the filling behavior of the cylinders depends on the instantaneous exhaust gas back pressure in the exhaust pipe of the engine, this instantaneous exhaust gas back pressure being able to be influenced by the gas flow pulse feed according to the invention.

Beim Öffnen des Auslaßventils eines Zylinders des Verbrennungsmotors entsteht im Auslaßkanal normalerweise momentan ein Druck von etwa 1,2 bis 1,5 bar, höchstens 2 bar. Die Druckquelle für das in Form von Strömungsimpulsen zuzuführende Gas soll daher in der Lage sein, Gas mit mindestens diesem Druck zu liefern. Bei üblichen Druckkesseln von Lastkraftwagen oder Omnibussen hat man problemlos einen Druck der erforderlichen Größe zur Verfügung.When the exhaust valve of a cylinder of the internal combustion engine is opened, a pressure of approximately 1.2 to 1.5 bar, at most 2 bar, is normally present in the exhaust port. The pressure source for the gas to be supplied in the form of flow pulses should therefore be able to supply gas at at least this pressure. With conventional pressure tanks of trucks or buses, you can easily have the required pressure available.

Als in Form von Strömungsimpulsen zuzuführendes Gas ist Luft besonders bevorzugt.Air is particularly preferred as the gas to be supplied in the form of flow pulses.

Die Erfindung und Ausgestaltungen der Erfindung werden nachfolgend anhand von zeichnerisch dargestellten Ausführungsbeispielen noch näher erläutert. Es zeigt:

Fig. 1
in schematischer Darstellung einen Verbrennungsmotor mit einer Einrichtung zum Zuführen zusätzlicher Strömungsimpulse in seine Abgasleitung;
Fig. 2
die von dem Verbrennungsmotor gelieferten Schalldruckimpulse und die zugeführten Strömungsimpulse in einem Diagramm;
Fig. 3
eine weitere Ausführungsform einer Einrichtung zum Zuführen von Strömungsimpulsen.
The invention and refinements of the invention are explained in more detail below with reference to exemplary embodiments illustrated in the drawings. It shows:
Fig. 1
a schematic representation of an internal combustion engine with a device for supplying additional flow pulses into its exhaust pipe;
Fig. 2
the sound pressure pulses delivered by the internal combustion engine and the supplied flow pulses in a diagram;
Fig. 3
a further embodiment of a device for supplying flow pulses.

In Fig. 1 ist ein Vierzylindermotor 2 mit dem vorderen Bereich seiner Abgasleitung 4 dargestellt. Es handelt sich um einen Otto-Motor, dessen Zündung durch eine Steuerelektronik 6 gesteuert ist. Alternativ könnte es sich um einen Diesel-Motor handeln, wobei in diesem Fall das Bezugszeichen 6 den Steuerungsbauteil der Einspritzpumpe darstellen würde. In Fig. 1 ist ferner ein Schalldämpfer 8 dargestellt, der ein Stück hinter dem Motor 2 in der Abgasleitung 4 sitzt. Weiter hinten in der Abgasleitung 4 und nicht eingezeichnet sitzt normalerweise mindestens ein weiterer Schalldämpfer.1 shows a four-cylinder engine 2 with the front area of its exhaust pipe 4. It is an Otto engine, the ignition of which is controlled by control electronics 6. Alternatively, it could be a diesel engine, in which case reference number 6 would represent the control component of the injection pump. In Fig. 1, a silencer 8 is also shown, which sits a bit behind the engine 2 in the exhaust pipe 4. At least one further silencer is normally located further back in the exhaust pipe 4 and not shown.

Ein Druckluftbehälter bzw. Druckkessel 10 wird durch einen intermittierend laufenden Kompressor 12 dauernd auf einem Druck von etwa 2 bis 6 bar gehalten. Von dem Druckkessel 10 führt eine Leitung 14 zu einer Einmündung 16 in die Abgasleitung 4, wobei die Einmündung 16 zwischen dem Motor 2 und dem Schalldämpfer 8 angeordnet ist. In der Leitung 14 sitzen hintereinander ein Magnetventil 18 und eine elektrisch verstellbare Drossel 20. Das Magnetventil 18 und die Drossel 20 können auch zu einem elektrisch betätigbaren Drosselventil kombiniert sein. Das Magnetventil 18 und die Drossel 20 sind elektrisch an die Steuerelektronik 6 angeschlossen.A compressed air tank or pressure vessel 10 is continuously kept at a pressure of approximately 2 to 6 bar by an intermittently running compressor 12. A line 14 leads from the pressure vessel 10 to an opening 16 into the exhaust gas line 4, the opening 16 being arranged between the engine 2 and the muffler 8. A solenoid valve 18 and an electrically adjustable throttle 20 are seated one behind the other in line 14. Solenoid valve 18 and throttle 20 can also be combined to form an electrically operable throttle valve. The solenoid valve 18 and the throttle 20 are electrically connected to the control electronics 6.

In Fig. 2 sind mit durchgezogenen Linien die Schalldruckimpulse 22 mit Schalldruckspitzen 24 eingezeichnet, wie sie in der Abgasleitung 4 dicht hinter dem Motor 2 auftreten. Jeder Schalldruckimpuls 22 ist einem Ausschiebetakt eines Zylinders des Motors 2 zugeordnet. Die Zeitbreite und der gegenseitige Abstand der Schalldruckimpulse 22 variiert mit der Drehzahl des Motors 2. Die Amplitude 26 der Schalldruckspitzen 24 varriert mit dem Lastzustand (z.B. Leerlauf, Halbgas, Vollgas) des Motors 2.2, the sound pressure pulses 22 with sound pressure peaks 24 are drawn in with solid lines, as occur in the exhaust gas line 4 close behind the engine 2. Each sound pressure pulse 22 is assigned to an extension stroke of a cylinder of the engine 2. The time width and the mutual spacing of the sound pressure pulses 22 vary with the speed of the engine 2. The amplitude 26 of the sound pressure peaks 24 varies with the load state (e.g. idling, half throttle, full throttle) of the engine 2.

Das Magnetventil 18 ist so gesteuert, daß jeweils zwischen zwei Schalldruckimpulsen 24 ein Strömungsimpuls 28 von Druckluft aus dem Druckkessel 10 an der Einmündung 16 ankommt. Jeder auf diese Weise zugeführte Strömungsimpuls 28 hat eine Zeitbreite derart, daß er zwischen zwei Schalldruckimpulse 22 paßt. Bei der gezeichneten Form stimmt der Zeitverlauf der Strömungsimpulse 28 nicht exakt mit dem zeitlichen Verlauf der Schalldruckimpulse 22 überein. Man kann jedoch das Magnetventil 18 so konzipieren, daß sich angenähert ein den Schalldruckimpulsen 22 entsprechender Zeitverlauf der Strömungsimpulse 28 ergibt. Das Diagramm der Fig. 2 zeigt die Impulse an der Einmündungsstelle 16.The solenoid valve 18 is controlled such that a flow pulse 28 of compressed air from the pressure vessel 10 arrives at the mouth 16 between two sound pressure pulses 24. Each flow pulse 28 supplied in this way has a time width such that it fits between two sound pressure pulses 22. In the form shown, the time course of the flow pulses 28 does not exactly match the time course of the sound pressure pulses 22. However, the solenoid valve 18 can be designed in such a way that a time course of the flow pulses 28 corresponding to the sound pressure pulses 22 results approximately. The diagram in FIG. 2 shows the impulses at the junction 16.

Bei der beschriebenen Vorrichtung wird also jeweils zwischen zwei von dem Motor 2 stammende Schalldruckimpulse 22 ein Strömungsimpuls von von außen zugeführter Druckluft gesetzt. Hierdurch ergibt sich hinter der Einmündungsstelle 16 eine Abgaspulsation im wesentlichen mit der doppelten Frequenz im Vergleich zu der Abgaspulsation vor der Einmündungsstelle 16. Bei der doppelfrequenten Abgaspulsation gestaltet sich die Schalldämpfung erheblich perfekter. Besonders das störende, niederfrequente, sonst praktisch nicht gut wegzudämpfende Brummen wird entscheidend reduziert.In the device described, a flow pulse of compressed air supplied from the outside is thus placed between two sound pressure pulses 22 originating from the motor 2. This results in behind at the confluence point 16, an exhaust gas pulsation essentially at twice the frequency compared to the exhaust gas pulsation upstream of the confluence point 16. With the double-frequency exhaust gas pulsation, the sound attenuation is considerably more perfect. In particular, the annoying, low-frequency hum that is otherwise practically not easily dampened is significantly reduced.

In Fig. 2 sind die Strömungsimpulse 28 mit einer Amplitude 26 eingezeichnet, die der Amplitude der Schalldruckimpulse 22 entspricht. Um dies auch bei wechselnden Lastzuständen des Motors 2 zu erreichen, ist die Drossel 20 vorgesehen. Die Drossel 20 wird bei höheren Lastzuständen des Motors 2 stärker geöffnet und bei niedrigeren Lastzuständen des Motors 2 stärker geschlossen.In Fig. 2, the flow pulses 28 are shown with an amplitude 26 which corresponds to the amplitude of the sound pressure pulses 22. In order to achieve this even with changing load conditions of the engine 2, the throttle 20 is provided. The throttle 20 is opened more strongly in the case of higher load states of the engine 2 and is closed more strongly in the case of lower load states of the engine 2.

Fig. 3 zeigt eine andere Möglichkeit zur Erzeugung der zuzuführenden Strömungsimpulse 28, und zwar in Form einer rotierenden Lochscheibe 30. Dicht vor der Lochscheibe 30 mündet eine Druckluftleitung 32. Die Lochscheibe 30 weist umfangsmäßig verteilt und beabstandet eine Reihe von dreieckförmigen Durchtrittsöffnungen 34 auf. Dicht hinter der Lochscheibe 30 beginnt eine Strömungsimpulsleitung 36, die an der Einmündungsstelle 16 in die Abgasleitung 4 eines in Fig. 3 nicht eingezeichneten Verbrennungsmotors 2 mündet.3 shows another possibility for generating the flow impulses 28 to be supplied, namely in the form of a rotating perforated disk 30. A compressed air line 32 opens directly in front of the perforated disk 30. The perforated disk 30 has a row of triangular through openings 34 distributed and spaced around the circumference. A flow pulse line 36 begins just behind the perforated disk 30 and opens at the junction 16 into the exhaust gas line 4 of an internal combustion engine 2 (not shown in FIG. 3).

Zu denjenigen Zeiten, in denen eine Durchtrittsöffnung 34 mit der Druckluftleitung 32 und der Strömungsimpulsleitung 36 ausgerichtet ist, wird ein Druckluft-Strömungsimpuls der Abgasleitung 4 zugeführt. Durch die geometrische Gestaltung der Druchtrittsöffnungen 34 kann man die zeitliche Impulsform der Strömungsimpulse 28 beeinflussen. In der Druckluftleitung 32 oder in der Strömungsimpulsleitung 36 kann eine variierbare Drossel vorgesehen sein. Der Antrieb der Lochscheibe 30 ist von dem Motor 2 abgeleitet, so daß eine Kopplung hinsichtlich Frequenz und Phasenlage zwischen den Strömungsimpulsen 28 und den Schalldruckimpulsen 22 gegeben ist.At those times when a passage opening 34 is aligned with the compressed air line 32 and the flow pulse line 36, a compressed air flow pulse is supplied to the exhaust line 4. The geometrical design of the passage openings 34 can influence the temporal pulse shape of the flow pulses 28. A variable throttle can be provided in the compressed air line 32 or in the flow pulse line 36. The drive of the perforated disk 30 is derived from the motor 2, so that there is a coupling with regard to frequency and phase position between the flow pulses 28 and the sound pressure pulses 22.

Die beschriebene Anordnung aus Druckluftleitung 32, rotierender Lochscheibe 30 und Strömungsimpulsleitung 36 bildet einen Pulsator 38, der eine von mehreren möglichen Bauarten eines Druckluftstrom-Zerhackers darstellt.The described arrangement of compressed air line 32, rotating perforated disk 30 and flow pulse line 36 forms a pulsator 38, which is one of several possible types of compressed air flow chopper.

Claims (11)

Verfahren zum Verbessern der Schalldämpfbarkeit des pulsierenden Abgasstroms eines Kolben-Verbrennungsmotors (2),
dadurch gekennzeichnet,
daß dem Abgasstrom zwischen den Schalldruckspitzen (24) Strömungsimpulse (28) eines Gases zugeführt werden.Method for improving the silenceability of the pulsating exhaust gas flow of a piston internal combustion engine (2),
characterized,
that the exhaust gas flow between the sound pressure peaks (24) flow pulses (28) of a gas are supplied. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß die Amplitude (26) der Strömungsimpulse (28) in Abhängigkeit von dem Lastzustand des Verbrennungsmotors (2) variiert wird.A method according to claim 1, characterized in that the amplitude (26) of the flow pulses (28) is varied depending on the load condition of the internal combustion engine (2). Vorrichtung zum Verbessern der Schalldämpfbarkeit des pulsierenden Abgasstroms eines Kolben-Verbrennungsmotors (2), dadurch gekennzeichnet, daß an die Abgasleitung (4) des Verbrennungsmotors (2) eine Einrichtung (10, 14, 18) angeschlossen ist, die dem Abgasstrom zwischen den Schalldruckspitzen (24) Strömungsimpulse (28) eines Gases zuführt.Device for improving the silenceability of the pulsating exhaust gas flow of a piston internal combustion engine (2), characterized in that a device (10, 14, 18) is connected to the exhaust gas line (4) of the internal combustion engine (2), which device controls the exhaust gas flow between the sound pressure peaks ( 24) supplies flow impulses (28) of a gas. Vorrichtung nach Anspruch 3, dadurch gekennzeichnet, daß die Einrichtung einen Druckkessel (10) und ein zugeordnetes, mit der erforderlichen Frequenz öffenbares und schließbares Ventil (18) aufweist.Apparatus according to claim 3, characterized in that the device has a pressure vessel (10) and an associated valve (18) which can be opened and closed with the required frequency. Vorrichtung nach Anspruch 4, dadurch gekennzeichnet, daß die Einrichtung einen mit der Drehzahl des Verbrennungsmotors (2) gekoppelten, mechanischen Gasstromzerhacker (38) für das zuzuführende Gas aufweist.Apparatus according to claim 4, characterized in that the device has a mechanical gas flow chopper (38), coupled to the speed of the internal combustion engine (2), for the gas to be supplied. Vorrichtung nach Anspruch 5, dadurch gekennzeichnet, daß der Zerhacker einen Drehschieber aufweist.Apparatus according to claim 5, characterized in that the chopper has a rotary valve. Vorrichtung nach Anspruch 5 oder 6, dadurch gekennzeichnet, daß der Zerhacker einen Hohlrotor mit Gasdurchtrittsöffnungen, dessen Innerem ein Gasstrom zugeführt wird, und einen Stator mit Gasdurchtrittsöffnungen aufweist.Apparatus according to claim 5 or 6, characterized in that the chopper has a hollow rotor with gas passage openings, the interior of which is supplied with a gas stream, and a stator with gas passage openings. Vorrichtung nach Anspruch 5, dadurch gekennzeichnet, daß der Zerhacker (38) eine rotierende Lochscheibe (30) aufweist.Apparatus according to claim 5, characterized in that the chopper (38) has a rotating perforated disc (30). Vorrichtung nach Anspruch 3 oder 4, dadurch gekennzeichnet, daß die Abstimmung der Strömungsimpulse (28) auf die Schalldruckspitzen (24) des Abgasstroms nach Frequenz und Phasenlage mittels einer elektrischen oder elektronischen Steuerung (6) erfolgt.Apparatus according to claim 3 or 4, characterized in that the flow pulses (28) are matched to the sound pressure peaks (24) of the exhaust gas flow according to frequency and phase position by means of an electrical or electronic control (6). Vorrichtung nach einem der Ansprüche 3 bis 9, dadurch gekennzeichnet, daß eine Einrichtung (20) zum Variieren der Amplitude (26) der Strömungsimpulse (28) in Abhängigkeit von dem Lastzustand des Verbrennungsmotors (2) vorgesehen ist.Device according to one of claims 3 to 9, characterized in that a device (20) for varying the amplitude (26) of the flow pulses (28) is provided as a function of the load state of the internal combustion engine (2). Vorrichtung nach Anspruch 10, dadurch gekennzeichnet, daß die Amplitudenvariierungseinrichtung (20) eine lastabhängig gesteuerte Drossel ist.Apparatus according to claim 10, characterized in that the amplitude varying device (20) is a throttle controlled as a function of the load.
EP91121051A 1990-12-28 1991-12-09 Device to improve the silence ability of the exhaust flow of an internal combustion engine Expired - Lifetime EP0492240B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4042124A DE4042124A1 (en) 1990-12-28 1990-12-28 METHOD AND DEVICE FOR IMPROVING THE SOUND ABSORBABILITY OF AN INTERNAL COMBUSTION ENGINE EXHAUST FLOW
DE4042124 1990-12-28

Publications (2)

Publication Number Publication Date
EP0492240A1 true EP0492240A1 (en) 1992-07-01
EP0492240B1 EP0492240B1 (en) 1997-01-08

Family

ID=6421628

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91121051A Expired - Lifetime EP0492240B1 (en) 1990-12-28 1991-12-09 Device to improve the silence ability of the exhaust flow of an internal combustion engine

Country Status (2)

Country Link
EP (1) EP0492240B1 (en)
DE (2) DE4042124A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102011089283A1 (en) * 2011-12-20 2013-06-20 Bayerische Motoren Werke Aktiengesellschaft Actuator arrangement for active exhaust systems and method for operating the same

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE654685C (en) * 1937-12-27 Willy Bestaendig Silencer for internal combustion engines
DE1043715B (en) * 1952-09-27 1958-11-13 Wilhelm Kubetzko Exhaust silencers for internal combustion engines, especially vehicle engines
EP0041831A1 (en) * 1980-06-06 1981-12-16 Pulse Air Research Limited Device for admitting air to the exhaust manifold of an internal combustion engine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE654685C (en) * 1937-12-27 Willy Bestaendig Silencer for internal combustion engines
DE1043715B (en) * 1952-09-27 1958-11-13 Wilhelm Kubetzko Exhaust silencers for internal combustion engines, especially vehicle engines
EP0041831A1 (en) * 1980-06-06 1981-12-16 Pulse Air Research Limited Device for admitting air to the exhaust manifold of an internal combustion engine

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 8, no. 195 (M-323)7 September 1984 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102011089283A1 (en) * 2011-12-20 2013-06-20 Bayerische Motoren Werke Aktiengesellschaft Actuator arrangement for active exhaust systems and method for operating the same

Also Published As

Publication number Publication date
DE59108470D1 (en) 1997-02-20
EP0492240B1 (en) 1997-01-08
DE4042124A1 (en) 1992-07-02

Similar Documents

Publication Publication Date Title
DE2823393C2 (en)
DE102004046184B4 (en) Method for exhaust noise attenuation in engines with cylinder deactivation
DE102018103806B4 (en) METHOD AND SYSTEM FOR REDUCING MALFUNCTIONS IN THE INTERIOR OF A VEHICLE AND MOTOR VEHICLE WITH SUCH A SYSTEM
DE2154155A1 (en) Exhaust system, especially for multi-cylinder internal combustion engines, with an even number of cylinders and two exhaust lines
DE102008002314A1 (en) Sound quality control device for an internal combustion engine
DE60200835T2 (en) SECONDARY AIR INTAKE TO THE EXHAUST SYSTEM OF A COMBUSTION ENGINE
DE4106418C2 (en)
DE3338870A1 (en) DEVICE FOR CONTROLLING THE CHANGE OF CHARGE IN INTERNAL COMBUSTION ENGINES
DE102004057251A1 (en) Fuel Injector with two separate Common Rails
WO1994004816A1 (en) Air-aspiration system for an internal-combustion engine
DE19717846A1 (en) Internal combustion engine with return of exhaust gas to incoming gas
EP0375758A1 (en) A method and device for lambda control with several probes.
DE3321841C2 (en)
EP0492240B1 (en) Device to improve the silence ability of the exhaust flow of an internal combustion engine
DE19638685C2 (en) Vaporized fuel recovery device for engines
DE19961775B4 (en) Control device for an internal combustion engine
DE102005027475A1 (en) Method and means for improved efficiency of cylinder deactivation engines
DE3702500C2 (en)
EP0364770B1 (en) Air intake resonance system for an internal-combustion engine
EP0278117B1 (en) Piston internal-combustion engine with an increased volumetric efficiency due to fresh gas resonant oscillations
DE4018612A1 (en) Twin-tube air intake for multi-cylinder combustion engine - has adjustable distributor in smaller tube whose length determines engine speed range corresp. to max. power
DE3722970A1 (en) Method and device for the cleaning of a particle filter, especially a soot filter
EP0368954A1 (en) Control system for diesel internal combustion engines.
DE112013006435T5 (en) Internal combustion engine with supercharger
DE3408355A1 (en) RESONANCE INTAKE SYSTEM FOR COMBUSTION ENGINES

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE DE FR IT SE

17P Request for examination filed

Effective date: 19921103

17Q First examination report despatched

Effective date: 19930118

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE DE FR IT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRE;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.SCRIBED TIME-LIMIT

Effective date: 19970108

Ref country code: FR

Effective date: 19970108

REF Corresponds to:

Ref document number: 59108470

Country of ref document: DE

Date of ref document: 19970220

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19970408

EN Fr: translation not filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19971231

26N No opposition filed
BERE Be: lapsed

Owner name: FIRMA J. EBERSPACHER

Effective date: 19971231

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20051231

Year of fee payment: 15

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070703