DE10102040A1 - Silencer, for a motor exhaust or turbo charger air intake, has a hollow body at the component to be suppressed containing a number of parallel Helmholtz resonators - Google Patents

Abstract

The silencer, at a motor exhaust or air intake, has a hollow body (8) at or in the component (7) where noise emissions are to be suppressed, to be linked to it or form a component part of it. A number of parallel Helmholtz resonators (10) are in at least one axial section (9) of the hollow body, in succession along the axial line of the body.

Description

The invention relates to a silencer on or in one Component in which there is a sound to be damped, in particular right airborne sound, spreads.

Silencers are used, for example, in internal combustion engines to reduce noise emissions to the environment uses. For example, silencers are in an exhaust tract an internal combustion engine arranged around the from the internal combustion engine engine generated and propagated sound to dampen. Silencers also come in motor vehicles in a fresh air tract of the internal combustion engine for use dung to z. B. charged with an exhaust gas turbocharger NEN internal combustion engine generated by the exhaust gas turbocharger dampen sound propagating in the fresh air tract.

For damping sound that spreads through a line tet, are so-called "shunt resonators" or "helmet holtz resonators ". Such a Helmholtz resonator consists essentially of a cavity that has a Connection opening communicates with the inside of the line, in which the sound to be damped spreads, whereby the The cavity is otherwise closed. The one enclosed in the cavity  The gas volume acts as a "spring" and the gas volume lumen in the connection opening acts as a "mass", causing an oscillatory system is formed. That pig system can be excited to vibrate by sound waves, whereby energy is extracted from the sound waves, i.e. the Sound is dampened. The damping effect of such Helmholtz resonator is however on a certain frequency or limited to a specific frequency band. The frequency or the frequency band in which the Helmholtz resonator is Damping effect depends, for. B. geometry, the cross-section, the length and thus the volume of the hollow space as well as the connection opening of the Helmholtz resonator from. A Helmholtz resonator can have its damping effect on best unfold when he is positio on the line is niert that its connection opening right there with the Inside the line communicates where in the line one Antinode of a standing sound wave from that Has trained frequency be from the Helmholtz resonator should be dampened. Due to the geometry of the line in which the sound propagates, those positions are in front given in which a standing sound wave is formed can. The exact position of an antinode can be at predetermined frequency can be calculated. For an optimal loading To achieve attenuation of a certain frequency, the Helmholtz resonator as precisely as possible at the calculated point be connected to the line. As part of a grande Series production, such as that used in the production of Motor vehicles or vehicle components is the rule can strictly adhere to a desired mounting position  can only be ensured with a relatively high effort. In addition, the range of a conventional Chen, equipped with a Helmholtz resonator attenuator, dampable frequencies very tight, so regularly only level peaks of certain frequencies can be damped.

The present invention addresses the problem an off for a silencer of the type mentioned Specify management form that is relatively easy to assemble and / or can be integrated while maintaining a high level of damping guaranteed. In addition, a silencer is said be specified, the improved damping effect and in particular has an increased broadband effect. Au In addition, the muffler is said to be particularly inexpensive to manufacture be cash.

According to the invention, this problem is solved by a silencer fer solved with the features of claim 1.

The invention is based on the general idea of a Silencers with several, especially with a multitude, To equip Helmholtz resonators arranged together are net and parallel to each other their sound absorbing we unfold. By the arrangement of the Helmholtz resonators in the direction of sound propagation one after the other the exact positioning of the silencer on or under construction part, e.g. B. a line in which to be damped Sound propagates, not because of the several Helmholtz resonators at least one inevitably close or direct  is positioned on an antinode. So there is none particularly precise assembly tolerances must be observed series production or series is made easier moderate equipment of a component with the invention Silencer.

Furthermore, it has been shown that the one with several, in parallel Acting silencers equipped with Helmholtz resonators develops a relatively broadband damping effect, so that the muffler according to the invention overall via a ver has better damping effect. This broadband effect arises in particular from a deliberate or tolerant nonuniformity of the individual Helmholtz resonators, that results from their manufacture.

An embodiment in which in an axial section of a hollow body of the silencer in one, in the axial direction and in the circumferential direction of the hollow body-extending zone several, parallel acting helmet wooden resonators in the axial direction one behind the other and in Um are arranged side by side. This way he there is a flat arrangement of a variety of helmets wooden resonators on the hollow body, reducing the damping effect or broadband is additionally increased.

A compact design results when neighboring Adjacent Helmholtz resonators. It is advantageous an embodiment in which they adjoin one another Helmholtz resonators share common walls or common  Own wall sections. This will manufacture the Helmholtz resonators simplified.

An embodiment in which the Cross sections of the Helmholtz resonators are small in ver equal to the cross section of the hollow body. This will create a Embodiment formed by its compactness distinguished and thus even with a relatively low one space is usable. It has been shown that the Helmholtz resonators due to their large number despite their rer small dimensions a relatively large damping effect unfold, so that the silencer according to the invention in Ver builds smaller than a conventional silencer, a sufficient damping effect with a larger band broad unfolds. Especially for high or higher frequencies zen, z. B. from about 900 Hz can with a small Large damping values can be achieved.

The damping effect, especially the broadband effect, of the silencer according to the invention can improve at least some of the Helmholtz resonators distinguish each other in that their cavities and / or their Connection openings of different lengths and / or cross cuts and / or geometries and / or orientations sen.

Special applications and uses of the invention Silencer result from claims 22 to 24.  

Other important features and advantages of the invention result itself from the dependent claims, from the drawings and from the associated description of the figures using the drawings.

It is understood that the above and the following standing features to be explained not only in the ever because specified combination, but also in other com binations or alone can be used without the To leave the scope of the present invention.

Preferred embodiments of the invention are in the Drawings are shown and are in the following Be spelling explained in more detail. Although the following exec Examples of a particular use of the invention explain muffler in an internal combustion engine, it is clear that this is without restricting the generality of the present invention. In particular, the inventor appropriate silencers are always used, when airborne sound is generated or transmitted in a device. The silencer according to the invention is suitable due to its compact design in a special way for one Use in or on smaller devices for high damping or higher frequencies, for example from 900 Hz for example, the silencer according to the invention Household appliances come into use, e.g. B. washing machine, Dishwasher, dryer, hair dryer, vacuum cleaner, Hood. There is also an application at elektromoto risch operated or compressed air operated tools possible Lich who work in particular at high speeds. Furthermore  can the muffler according to the invention z. B. at Exhaust fans, cooling fans, air extraction systems, air conditioning computers are used to specifically Dampen frequencies.

Each shows schematically

Fig. 1 is a circuit diagram-like schematic diagram of an internal combustion engine which is equipped with a silencer according to the invention,

Fig. 2 is a longitudinal section through a silencer,

Fig. 3 shows a cross section through a silencer according to the invention and

Fig. 4 is a cross section as in Fig. 3, but in another embodiment.

According to Fig. 1, a silencer 1 according to the invention are used in an internal combustion engine 2 is used, there to attenuate sound generated substantially from an exhaust gas turbo charger 3 of the engine 2. The sound damper 1 is arranged for this purpose in a fresh air tract 4 downstream of an air filter 5 and upstream of a compressor 6 of the exhaust gas turbocharger 3 . Here, the Schalldämp fer 1 in a component, namely installed in a line 7 of the fresh air path 4 is thus traversed by the transported in the fresh air tract 4 air and forms a part of the extent of the line. 7 The sound generated by the exhaust gas turbocharger 3 propagates through the line 7 against the direction of flow and would - in the absence of a silencer 1 - reach the air filter 5 relatively undamped and finally exit into the environment. By Einbin the muffler 1 manure in the pipe 7 the spreading in the line 7 can sound with respect to certain frequencies or frequency bands are attenuated, the sound emission of the overall arrangement thus can be reduced. The muffler 1 is preferably positioned as close as possible to the sound source whose sound is to be dampened, ie here, close to the exhaust gas turbocharger 3 . In the example, the muffler 1 is arranged on the clean air side, that is to say downstream of the air filter 5 ; an arrangement on the raw air side is also possible.

Preferably, the arrangement shown in FIG. 1 is again found in a motor vehicle which contains the internal combustion engine 2 as the drive motor. The invention can also be applied to stationary internal combustion engines 2 . In the embodiment shown here, the higher-frequency sound generated by the exhaust gas turbocharger 3 is to be attenuated at least in certain frequencies. Likewise, it is z. B. in an internal combustion engine without exhaust gas turbocharger possible from the internal combustion engine or components thereof, for. B. damped by the valves of the internal combustion engine 2 generated sound.

According to FIG. 2, the muffler 1 according to the invention to a tubular hollow body 8, which forms a part of the pipe 7, in which the silencer 1 is based incorporated or is incorporated. The hollow body 8 can, as here, be cylindrical. Other embodiments, e.g. B. with conical hollow body are also possible Lich.

In a direction indicated by a brace axial portion 9 of the hollow body 8, which here extends along the entire hollow body 8 are on an outside 8 of the hollow body a plurality of Helmholtzresonato ren 10 in the axial direction one behind the other and circumferentially arranged side by side. Each of these Helmholtz resonators 10 has a cavity 11 , and each of these cavities 11 communicates with an interior 13 of the hollow body 8 via a single connection opening 12 . Otherwise, the cavities 11 of the Helmholtz resonators 10 are closed. Due to the selected arrangement of the Helmholtz resonators 10 , they interact simultaneously and thus in parallel with the interior 13 of the hollow body 8 or the line 7 . It is worth noting that the individual Helmholtz resonators 10 are of relatively small dimensions in comparison equal to the line 7, since the cross sections of the Helmholtz resonators space 10 and the hollow 11 are small compared to the cross section of the line 7 or the hollow body. 8 Nevertheless, the silencer 1 according to the invention, in particular at higher frequencies, for. B. from 900 Hz, develop a relatively strong damping effect, which is attributed to the large number of individual, parallel-acting Helmholtz resonators 10 .

According to FIG. 3 may be formed pers 8 two zones 14 in the axial portion 9 of the Hohlkör, in each of which ne by side and arranged behind one another Helmholtzresonä gates 10 are formed. These zones 14 extend only partially along the circumference of the hollow body 8 and are arranged opposite one another on the hollow body 8 according to FIG. 3. In contrast to this, in accordance with the embodiments from FIGS. 2 and 4, a single zone 14 can also be formed, which extends along the entire circumference of the hollow body 8 and thus completely surrounds it in the circumferential direction. Accordingly, the Helmholtz resonators 10 are also arranged next to one another on the hollow body 8 along the entire circumference. Other embodiments can also have more than two such zones 14 .

While in the embodiment according to FIG. 3, the Helmholtz resonators 10 and the cavities 11 and their Verbin dung openings are aligned parallel to one another 12, Fig. 4 shows an embodiment in which the Helmholtzre sonatoren 10 or its cavities 11 and their Verbin dung openings 12 are aligned radially to a longitudinal axis 15 of the Hohlkör pers 8 .

In the embodiments shown, adjacent Helmholtz resonators 10 adjoin one another. In addition, the adjacent Helmholtz resonators 10 have common walls or wall sections 16 , which simplifies their manufacture. The cavities 11 of the Helmholtz resonators 10 can in principle have any cross sections. However, circular, rectangular or hexagonal cross sections are preferred.

At least some of the Helmholtz resonators 10 can differ from one another in that their cavities 11 and / or their connecting openings 12 have different lengths and / or cross sections and / or geometries and / or orientations. As a result, the damping behavior, in particular the broadband effect, of the silencer 1 can be influenced.

Referring to FIGS. 3 and 4, the hollow body 8 has a circular cross-section. It is clear that the hollow body 8 can in principle have any cross section, at least in the region of its axial section 9 , in particular a rectangular or polygonal cross section.

According to FIG. 2, an embodiment is preferred in which, at least in the axial direction of the hollow body 8, a distance 17 between the connection openings 12 of two adjacent Helmholtz resonators 10 is smaller than a whole or half a wavelength of a frequency to be attenuated or smaller than a whole or one half the average wavelength of a frequency band to be attenuated. This construction ensures that when the silencer 1 according to the invention is installed, the exact positioning of the silencer 1 on or in the line 7 is not important. For as long as the equipped with the Helmholtz resonators 10 is axial section 9 tioniert posi in the region of an antinode, at least is one of the Helmholtzre sonatoren 10 relatively close to or exactly at the maximum of the oscillations supply abdomen. In this way, an optimal damping effect for the silencer 1 can always be guaranteed.

In a preferred embodiment, the muffler 1 according to the invention can be constructed such that the cavities 11 of at least some of the Helmholtz resonators 10 are formed in a common block which has, for example, a honeycomb structure or "honeycomb structure". This block then forms a separately producible component that can be attached to a wall section of the hollow body 8 . This wall section is equipped with the connection openings 12 . A suitable connection opening 12 is assigned to each cavity 11 by a suitable placement of the said block on the wall section provided for this purpose. The wall section thus delimits the block radially on the inside. Ra dial outside the block is limited, for example, by a common cover that closes the cavities 11 radially on the outside. For example, the two zones 14 provided in the embodiment according to FIG. 3 can each be formed in this way. It can be formed on the hollow body 8 egg ne type housing, in which the separately manufactured block containing the cavities 11 can be used. By closing this housing with a suitable lid, the cavities 11 are simultaneously closed radially on the outside. The block can be connected to the wall section of the hollow body 8 and / or with the cover in a suitable manner, in particular welded.

The component in which the sound to be damped spreads out, is formed in the exemplary embodiment described by the line 7 . Other embodiments are also possible, in which the component in which the sound to be damped is formed by another component of the fresh air track, for example by the air filter 5 or by a fresh air collector 18 , from which the fresh air supplied to the individual cylinder of the internal combustion engine 2 distributed (see. Fig. 1). Before preferably the hollow body of the muffler then forms a housing or a component, for. B. a housing wall of the component. For example, the sound damper according to the invention can be formed on or in the lid of the air filter 5 . In principle, the muffler can be designed as an attachment or as an installation part which is mounted on or in the respective component. It is also possible to design the silencer as an integral part of the respective construction part. For example, the muffler is integrated into the housing of the air filter 5 or air collector 8 .

Claims (24)

1. silencer on or in a component ( 7 ) in which a sound to be damped propagates, with a hollow body ( 8 ) which communicates with the component ( 7 ) or forms part of the component ( 7 ), at least in an axial section ( 9 ) of the hollow body ( 8 ) a plurality of Helmholtz resonators ( 10 ) acting in parallel in the axial direction of the hollow body ( 8 ) are arranged one behind the other. 2. Muffler according to claim 1, characterized in that in the axial section ( 9 ) of the hollow body ( 8 ) a plurality of par allel acting Helmholtz resonators ( 10 ) in the circumferential direction of the hollow body ( 8 ) are arranged side by side. 3. Muffler according to claim (2), characterized in that in the axial section ( 9 ) of the hollow body ( 8 ) in a, in the axial direction and in the circumferential direction of the hollow body ( 8 ) extending zone ( 14 ) a plurality of parallel-acting helmet holtz resonators ( 10 ) are arranged one behind the other in the axial direction of the hollow body ( 8 ) and next to one another in the circumferential direction of the hollow body ( 8 ). 4. Silencer according to claim 3, characterized in that the zone ( 14 ) completely surrounds the hollow body ( 8 ) in the circumferential direction. 5. Silencer according to claim 3, characterized in that two or more zones ( 14 ) distributed in the circumferential direction are formed on the hollow body ( 8 ). 6. Silencer according to one of claims 1 to 5, characterized in that adjacent Helmholtz resonators ( 10 ) adjoin each other. 7. A silencer according to claim 6, characterized in that adjacent Helmholtz resonators (10) have common walls or wall portions (10). 8. Silencer according to one of claims 1 to 7, characterized in that the cross sections of the Helmholtz resonators ( 10 ) are small compared to the cross section of the hollow body ( 8 ). 9. Silencer according to one of claims 1 to 8, characterized in that each Helmholtz resonator ( 10 ) has a cavity ( 11 ) which communicates via a separate connection opening ( 12 ) with the interior ( 13 ) of the hollow body ( 8 ). 10. Muffler according to claim 9, characterized in that a distance ( 17 ) between the connection openings ( 12 ) of adjacent Helmholtz resonators ( 10 ) is less than one or half a wavelength of a frequency to be damped or is less than one or half a medium wave length of a frequency band to be attenuated. 11. Silencer according to one of claims 1 to 10, characterized in that each Helmholtz resonator ( 10 ) has a cavity ( 11 ), the cavities ( 11 ) of a plurality of Helmholtz resonators ( 10 ) are closed radially on the outside with a common cover. 12. Silencer according to one of claims 1 to 11, characterized in that at least some of the Helmholtz resonators ( 10 ) differ from one another in that their cavities ( 11 ) and / or their connecting openings ( 12 ) have different lengths and / or cross sections and / or have geometries and / or orientations. 13. Silencer according to one of claims 1 to 12, characterized in that at least some of the Helmholtz resonators ( 10 ) are aligned parallel to one another. 14. Silencer according to one of claims 1 to 13, characterized in that at least some of the Helmholtz resonators ( 10 ) are aligned radially to a longitudinal axis ( 15 ) of the hollow body ( 8 ). 15. Silencer according to one of claims 1 to 14, characterized in that at least some of the Helmholtz resonators ( 10 ) are formed on the hollow body ( 8 ) in that the cavities ( 11 ) of these Helmholtz resonators ( 10 ) containing common block radially outside through a common cover and radially on the inside by a common, the Verbindungsöffnun gene ( 12 ) of these Helmholtz resonators ( 10 ) containing wall section of the hollow body ( 8 ) is limited. 16. A silencer according to claim 15, characterized, that the block has a honeycomb structure. 17. Silencer according to one of claims 1 to 16, characterized in that the hollow body ( 8 ) forms a housing or a housing component of the component ( 7 ). 18. Muffler according to one of claims 1 to 17, characterized in that the muffler ( 1 ) as an attachment for attachment to the component ( 7 ) or as an installation part for installation in the component ( 7 ) or as an integral part of the component ( 7 ) is trained. 19. Silencer according to one of claims 1 to 18, characterized in that the component ( 7 ) forms part of a fresh air tract ( 4 ) or an exhaust tract of an internal combustion engine ( 2 ). 20. Muffler according to claim 19, characterized in that the muffler ( 1 ) in the fresh air tract ( 4 ) downstream egg nes air filter ( 5 ) and upstream of an exhaust gas turbocharger ( 3 ) of the internal combustion engine ( 2 ) is arranged. 21. Silencer according to claim 19 or 20, characterized in that the component is formed by a line ( 7 ) or an air filter or an air collector. 22. Use of a silencer ( 1 ) according to one of claims 1 to 21 on or in a device which is driven by an internal combustion engine or by an electric motor or by compressed air. 23. Use according to claim 22, characterized, that the device by a motor vehicle or a washing machine ne or a dishwasher or a tumble dryer or one  Hair dryer or a vacuum cleaner or an exhaust fan blower or an air extraction system or a compressed air company Nes or electromotive tool is formed. 24. Use of a silencer ( 1 ) according to one of claims 1 to 21 for damping sound in the range of relatively high frequencies, for. B. from about 900 Hz.