DE202011001554U1 - Exhaust assembly for use with an internal combustion engine - Google Patents

Abstract

An exhaust assembly (01, 14) for use with an internal combustion engine, the exhaust assembly (01, 14) comprising: means (02) for connecting to the internal combustion engine, at least one exhaust, and at least one muffler; wherein control means (05, 17) for controlling the damping characteristic of the exhaust assembly are provided, and wherein the exhaust assembly (01, 14) at least a first combustion gas flow path and a second combustion gas flow path, and wherein the control means (05, 17) during use with a Combustion engine connected exhaust assembly (01, 14) are selectively operable by an operator, and wherein the control means (05, 17) are able to selectively distribute an approximately constant current generated by the combustion gases of the engine regardless of the volume of the combustion gases on the combustion gas flow paths wherein the first combustion gas flow path includes at least one damper, and wherein the second combustion gas flow path has substantially no damper, so that the combustion gas flow paths have substantially different damping characteristics from each other have, characterized in that the damping means of the first combustion gas flow path comprise a high-frequency damper (11, 23), ...

Description

The invention relates to an exhaust assembly for use with an internal combustion engine according to the preamble of claim 1. Such an exhaust assembly is known from DE 697 02 447 T2 known.

In the known exhaust arrangement two separate combustion gas flow paths are controllable to change the damping characteristic of the exhaust assembly. As a control arrangement, in particular a rotatably mounted valve is used, with which the combustion gas flow paths can be selectively blocked or opened in order to change the gas distribution in the two combustion gas flow paths. The exhaust arrangement is characterized in that the two combustion gas flow paths have a different damping characteristic. The first combustion gas flow path is characterized by a damping device with which the combustion gases emitted by the exhaust system can be silenced. On the other hand, the second combustion gas flow path is characterized by the fact that no or only an attenuated damping device is provided, so that the combustion gases flowing out along the second combustion gas flow path are not silenced or attenuated.

As a result, by actuating the control device, the user thus has the option of optionally changing over the damping characteristic of the exhaust arrangement. If the combustion gases are passed over the first combustion gas flow path, the combustion gases are silenced and the noise is reduced accordingly. On the other hand, when the combustion gases are conducted via the second combustion gas flow path, the combustion gases flow unattenuated at a correspondingly higher power of the internal combustion engine and cause a higher noise level.

These known exhaust arrangements are used in particular in large-volume combustion engines of motorcycles. The users of such motorcycles preferably want a low-frequency as possible noise characteristic that is reminiscent of a Blubberger sound. Investigations have now shown that undesirable, namely relatively high noise frequencies are generated by the required in generic exhaust arrangements, which is often designed in the manner of a valve flap, whereas the desired low frequency components are filtered out by the damping device in the first combustion gas flow path. As a result, the known exhaust arrangements of the control device for changing the damping characteristic therefore have a noise characteristic which is often criticized with regard to the frequency distribution.

Object of the present invention is therefore to propose a new exhaust assembly for use with an internal combustion engine, the damping characteristic can be changed by a control device and thereby has an improved noise characteristics.

This object is achieved by an exhaust arrangement according to the teaching of claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims.

The exhaust arrangement according to the invention is based on the basic idea that the damping devices of the first combustion gas flow path comprise a high-frequency damper, with the high-frequency damper predominantly higher frequencies of the frequency spectrum contained in the combustion gas can be attenuated. The term high-frequency damper is thus to be understood that the high-frequency damper is suitable for damping the relatively higher frequencies of the frequency spectrum contained in the combustion gas. It is therefore not the attenuation of high-frequency oscillations of the electromagnetic wave spectrum. By damping these higher frequencies of the frequency spectrum contained in the combustion gas, the noise characteristics of the exhaust system is significantly improved because the unwanted higher-frequency frequencies are removed or reduced. On the other hand, the high-frequency damper has no significant influence on the desired lower frequencies of the frequency spectrum contained in the combustion gas. As the high-frequency damper of the exhaust assembly according to the invention is designed constructively, is basically arbitrary. However, the design of the high-frequency damper in the manner of a closed sound-collecting chamber, which communicates with the first combustion gas flow path via sound passage openings, is preferred. The sound passage openings are not part of the first combustion gas flow path and are not substantially traversed by the combustion gas. Rather, only the sound waves pass through the sound passage openings and are selectively damped in the closed sound chamber so that predominantly higher frequencies are removed or reduced. On the desired lower frequencies, the closed sound chamber, however, has only a very small or no influence.

In order to enhance the desired damping effect for damping the higher frequencies of the frequency spectrum contained in the combustion gas, the sound-absorbing chamber can be filled with a damping material, for example with insulating wool.

A particularly easy and inexpensive to manufacture embodiment of the exhaust assembly according to the invention is obtained when the exhaust assembly has a gas-tight housing and a perforated inner tube spaced therefrom. The housing is closed on one side around the inner tube and connected via connecting means with a combustion gas supply pipe. At a distance from the connecting devices, a valve device is then provided for completely or partially closing the inner tube. When the valve device is open, the combustion gas can then escape without interruption through the inner tube into the environment, so that the inner tube forms the second combustion gas flow path when the valve device is open. If the valve device is closed, the combustion gas can no longer flow out through the inner tube, but is deflected at the valve device. As a result, the combustion gas then flows first via the inner tube and via perforation openings formed therein into a bypass, which comprises the inner tube in a cylindrical shape and forms part of the first combustion gas flow path. From this bypass, the combustion gas can then then again flow back through perforation openings in the inner tube to emanate from there into the environment or the combustion gas flows directly from the bypass into the environment. Damping devices could optionally be installed in the bypass behind the perforation openings of the inner tube. On the inside of the housing, which in turn forms the outside of the bypass for the first combustion gas flow path, the sound passage openings of the cylindrically formed sound collecting chamber can be arranged. As a result, the combustion gas then flows out through the bypass and passes through the sound passage openings of the sound collecting chamber surrounding this bypass in a cylindrical manner.

In the exhaust arrangement with inner tube and valve device, it is particularly advantageous if the cylindrical sound collecting chamber is formed by a gas-tight, outer housing wall and a perforated, inner Schalldurchtrittswandung. The perforation in the sound passage wall need not be completely formed, but also the partial perforation of the sound passage is already sufficient in many cases.

In order to enhance the desired damping effect for damping the higher frequencies of the frequency spectrum contained in the combustion gas, according to a preferred embodiment in the first combustion gas flow path, a deflecting element is provided, with which the flow path of the combustion gases along the perforated, inner Schalldurchtrittswandung the sound chamber is extended. Through this extended flow path along the sound passage wall of the sound-collecting chamber, a correspondingly higher proportion of the sound waves is passed through the Schalldurchtrittswandungen and attenuated correspondingly higher.

In order to be able to remove or reduce the undesired higher frequencies of the frequency spectrum contained in the combustion gas even when these frequencies arise during the outflow along the second combustion gas flow path, additional sound passage openings may also be present between the second combustion gas flow path and the sound-absorbing chamber. As a result, the sound collecting chamber can then combine to attenuate both the higher frequencies of the frequency spectrum contained in the combustion gas contained in the first combustion gas flow path and in the second combustion gas flow path.

In order to realize the combined damping of the higher frequencies in both the second combustion gas flow path and the first combustion gas flow path, the additional sound passage openings may be disposed in the common flow path formed by the first and second combustion gas flow paths.

If an embodiment of the exhaust arrangement is used, which has an inner tube, then this inner tube can preferably also have sound passage openings which are not part of the first combustion gas flow path and are substantially not traversed by the combustion gas.

Two embodiments of the exhaust assembly according to the invention are shown schematically in the drawings and are explained below by way of example.

Show it:

1 a first embodiment of an exhaust assembly according to the invention in longitudinal section;

2 a second embodiment of an exhaust assembly according to the invention in longitudinal section.

1 shows a first embodiment 01 an exhaust assembly according to the invention, via a combustion gas supply pipe 02 is connected to an internal combustion engine, not shown. The exhaust arrangement 01 consists essentially of an inner tube 03 , a gas-tight housing 04 and a valve device 05 , By pivoting the valve device 05 can the cross section of the inner tube 03 opened and closed by a user. Is the valve device 05 open, so can from the combustion gas supply pipe 02 combustion gas entering the exhaust assembly without substantial damping and without interruption by the inner tube 03 emanate into the environment. This undamped and uninterrupted flow path through the inner tube 03 forms the second combustion gas flow path in the sense of the present invention.

Will the valve device 05 closed like it is in 1 is exemplified, then the flow path through the inner tube 03 interrupted and the combustion gas flows through openings 06 in a cylindrical bypass channel 07 , At the end of the bypass channel 07 the combustion gases then flow through openings again 08 back into the inner tube 03 and from there into the environment. This corresponds to the first combustion gas flow path in the sense of the present invention and is represented by the flow arrows 09 indicated schematically.

The bypass channel 07 is on the outside of a perforated, internal Schalldurchtrittswandung 10 limited, having a plurality of sound passage openings. Through these sound openings in the Schalldurchtrittswandung 10 becomes the bypass channel 07 the first combustion gas flow path with a cylindrical sound chamber 11 connected between the gas-tight outer housing wall 04 and the perforated, internal sound passage wall 10 is formed. The in the bypass channel 07 the first combustion gas flow path resulting higher frequencies are passing through the sound passage openings in the Schalldurchtrittswandung 10 heavily damped. In the sound chamber 11 is to reinforce the damping effect damping wool 12 introduced in 1 is indicated by dashed lines. The perforation of the sound passage wall 10 sits down at the transition to the inner tube 03 so that also the inner tube 03 the only schematically indicated sound passage openings 13 having. Through the sound passage openings 13 in the inner tube 03 For example, the higher frequencies of the frequency spectrum contained in the combustion gas can be damped even when the valve device 05 is open.

2 shows a second embodiment 14 an exhaust assembly according to the invention, which in turn is a combustion gas supply pipe 02 for supplying the combustion gases from an internal combustion engine. Also the exhaust arrangement 14 consists essentially of an inner tube 15 , a housing wall 16 and a valve device 17 , When the valve device is open 17 The combustion gas can continuously from the combustion gas supply pipe 02 through the inner tube 15 emanate into the environment. Due to the lack of damping, this increases performance and increases noise. Will the valve device 17 closed, the combustion gases flow through openings 18 in a bypass channel 19 , wherein the combustion gases at a deflecting element 20 be redirected in the opposite direction. At the end of the bypass channel 19 The combustion gases then flow through openings 21 and 22 back into the inner tube 15 and from there into the environment. The bypass channel 19 is at the exhaust assembly 14 again from a cylindrical sound chamber 23 includes, the inner Schalldurchtrittswandung 24 with a plurality of merely indicated sound passage openings 25 perforated. The through the sound openings 25 from the bypass channel 19 in the sound chamber 23 penetrated sound waves are strongly attenuated with respect to the higher frequencies contained in the frequency spectrum and thus the desired damping effect is made possible. By the deflection 20 becomes the flow path of the combustion gases along the Schalldurchtrittswandung 24 with the sound openings 25 greatly extended and thus the damping effect increased accordingly. The insulating wool 26 in the sound chamber 23 is in 2 again indicated by dashed lines. The front part of the inner tube 15 can in front of the openings 18 also with sound openings 25 be perforated to the passage of sound waves when the valve device is open 17 to enable.

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 69702447 T2 [0001]

Claims (9)

Exhaust assembly ( 01 . 14 ) for use with an internal combustion engine, the exhaust assembly ( 01 . 14 ): a device ( 02 ) for connecting to the internal combustion engine, at least one exhaust, and at least one muffler; whereby control devices ( 05 . 17 ) are provided for controlling the damping characteristic of the exhaust assembly, and wherein the exhaust assembly ( 01 . 14 ) has at least a first combustion gas flow path and a second combustion gas flow path, and wherein the control devices ( 05 . 17 ) during use of the exhaust assembly connected to an internal combustion engine ( 01 . 14 ) are selectively operable by an operator, and wherein the control means ( 05 . 17 ) are capable of selectively distributing an approximately constant current generated by the combustion gases of the engine to the combustion gas flow paths regardless of the volume of the combustion gases, the first combustion gas flow path having at least one damper, and the second combustion gas flow path having substantially no damper means, so that the combustion gas flow paths have substantially different damping characteristics, characterized in that the damping devices of the first combustion gas flow path comprise a high-frequency damper ( 11 . 23 ), wherein with the high-frequency damper predominantly higher frequencies of the frequency spectrum contained in the combustion gas can be attenuated. Exhaust assembly according to claim 1, characterized in that the high-frequency damper in the manner of a closed sound-absorbing chamber ( 11 . 23 ) is formed with the first combustion gas flow path via sound passage openings ( 13 . 25 ), wherein the sound openings ( 13 . 25 ) are not part of the first combustion gas flow path and are substantially not traversed by the combustion gas. Exhaust assembly according to claim 1 or 2, characterized in that the sound collecting chamber ( 11 . 23 ) with a damping material, in particular with insulating wool ( 12 . 26 ) is completed. Exhaust assembly according to one of claims 1 to 3, characterized in that the exhaust arrangement ( 01 . 14 ) a gas-tight housing ( 04 . 16 ) and a spaced-apart perforated inner tube ( 03 . 15 ), wherein the housing ( 04 . 16 ) is closed on one side around the inner tube, and at a distance from the connecting means ( 02 ) a valve device ( 05 . 17 ) for complete or partial closing of the inner tube ( 03 . 15 ), and wherein the arrangement is designed such that when the valve device is open ( 05 . 17 ) the second Verbrennnungsgasströmungsweg without interruption by the inner tube ( 03 . 15 ) extends into the environment to form a free flow path, while with the valve device closed ( 05 . 17 ) the first combustion gas flow path via the inner tube ( 03 . 15 ) and the perforations formed therein ( 06 . 08 ; 18 . 22 ) through a bypass channel ( 07 . 19 ) between the inner tube ( 03 . 15 ) and the housing ( 04 . 16 ) into the environment, and being on the inside of the housing ( 04 . 16 ) the cylindrical sound collecting chamber ( 11 . 23 ) is arranged, which via sound passage openings ( 13 . 25 ) communicates with the first combustion gas flow path. Exhaust arrangement according to one of claims 1 to 4, characterized in that the cylindrical sound collecting chamber ( 11 . 23 ) of a gas-tight, outer housing wall ( 04 . 16 ) and a perforated, internal Schalldurchtrittswandung ( 13 . 25 ) is formed. Exhaust arrangement according to one of claims 1 to 5, characterized in that in the first combustion gas flow path, a deflection element ( 20 ) is provided, with which the flow path of the combustion gases along the perforated inner Schalldurchtrittswandung ( 24 ) of the sound collecting chamber ( 23 ) is extended. Exhaust assembly according to one of claims 1 to 6, characterized in that additional sound passage openings are present between the second Verbrennnungsgasströmungsweg and the sound-absorbing chamber. Exhaust assembly according to one of claims 1 to 7, characterized in that also between the common flow path, which is formed jointly by the first and second Verbrennnungsgasströmungsweg, and the sound collecting chamber ( 11 ) additional sound openings ( 13 ) available. Exhaust assembly according to one of claims 1 to 8, characterized in that the inner tube has sound passage openings which are not part of the first combustion gas flow path and are not substantially traversed by the combustion gas.

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