WO2006018336A1

WO2006018336A1 - Soundproofing device and device for conducting a fluid

Info

Publication number: WO2006018336A1
Application number: PCT/EP2005/052756
Authority: WO
Inventors: Matthias Flucht; Christoph Heiland; Uwe Gross; Peter Altenhofen
Original assignee: Geiger Technik Gmbh
Priority date: 2004-06-16
Filing date: 2005-06-14
Publication date: 2006-02-23
Also published as: US20070295554A1; DE102004029221A1

Abstract

The invention relates to a device (1) for soundproofing the noise that is generated by a fluid in a conduit, in particular the noise that is generated in the induction line of an internal combustion engine. Said device comprises a wall (3), whose inner face delimits a traversing zone for the fluid. The device is at least partly tubular, i.e. it comprises two openings. The outer face of the wall (3) is provided with a plurality of chambers (4), which are respectively connected to the traversing zone via an opening (7). The chambers (4) are delimited by the outer face of the wall (3) and by struts (5, 6, 8) that are formed on the outer face of the wall (3). When operational, the chambers (4) act as Helmholtz resonators. The invention also relates to a device for conducting a fluid, comprising the inventive soundproofing device (1).

Description

Acoustic damping device and device for conducting a fluid

The invention relates to a device for sound attenuation of the sound generated by a fluid in a duct, in particular of the sound generated in an intake pipe of an internal combustion engine. Furthermore, the invention relates to a device for conducting a fluid, in particular for supplying air to an internal combustion engine, comprising a duct.

For damping or insulation unwanted noise caused by the flow of fluids, especially air or exhaust gases through pipes, different concepts are known. On the one hand, it is possible to form holes at the points in pipelines at which the standing waves forming in the tube have amplitude maxima, so that a derivation of the vibration energy to the outside is possible in order to achieve the desired damping. It is exploited that the engine compartment is usually well shielded acoustically, so that the derived vibrations in the engine compartment are further attenuated and can not escape to the outside.

Alternatively, it is conceivable to absorb the sound at least partially directly in the tube.

For this purpose, various acoustic components have been developed for the engine compartment, which should meet the thermal, mechanical and acoustic properties. In the known solutions, however, it has been found that in the provision and installation of the components high production costs, high material costs and a considerable effort during installation or conversion, especially when retrofitting already existing systems arises.

It is the object of the invention to provide a silencer that allows optimized noise damping and is easy to manufacture. In addition, the possibility of integration into existing systems is particularly desirable. This object is achieved by a device for sound damping gem. Claim 1 and a device for conducting a fluid according to claim 20.

The device for sound damping of a fluid in a

Conduit generated sound, in particular of the sound generated in an intake manifold of an internal combustion engine, comprises a wall, the inside of which delimits a flow area for the fluid. In particular, the sound attenuation device on an outside of the wall has a plurality of chambers communicating with the flow area.

The said device is arranged in particular in a duct. The device may also be suitable for retrofitting an already existing duct with sound insulation. As a duct, for example, a charge air tube of a turbocharger, e.g. the intake pipe between the air filter and a turbocharger, the intake pipe of an internal combustion engine, an exhaust pipe or the like into consideration.

However, it can also be retrofitted with the device according to the invention all possible other lines, such as an exhaust pipe when using an exhaust gas turbocharger. The silencer can be used anywhere in an air duct system to reduce noise. Thus, an optimal use of the scarce space in the engine area and the best possible noise attenuation in a compact design of the device can be achieved.

Preferably, each of the chambers communicates with the flow area via at least one opening. As a rule, an opening is provided between each chamber and the flow area.

The dimensioning of the chambers is designed so that the

Dimensions compared to the insulating or damping standing wave are low.

The cross section of the openings is usually also small compared to the wavelength of the sound wave to be damped. 13] The chambers are preferably bounded by the outside of the wall and by webs formed on the outside of the wall.

The webs are in particular aligned substantially perpendicular or parallel to the main flow direction of the fluid. At the edge regions of the device and webs may be provided which form a Teii of Begrenzungsflanschen and Randwulsten, these types of webs can extend in any direction.

The chambers are provided to act as Helmholtz resonators. As a rule, a Helmholtz resonator is a perforated plate which is at a distance from a wall, in this case from the boundary wall of the duct. This distance of the perforated plate from the wall in the present construction corresponds to the distance between the boundary wall of the duct and the flow-restricting wall (the sound attenuator), which essentially takes over the function of the perforated plate. This distance in turn corresponds substantially to the height of the webs. The Helmholtz resonator acts like a selective spring-mass system, which is excited to vibrate by the impinging sound waves. Depending on the volume, ie in particular the length, width and height of the chambers, as well as on the dimensioning of the openings, a narrow-band attenuation of the sound waves occurs because internal losses occur due to the excitation of oscillations of the Helmholtz resonators. At resonance, the effect of the Helmholtz resonator is greatest.

In a particular embodiment, chambers with different volumes and / or openings with different opening cross-sections are provided. As a result, broadband can be attenuated over a wide spectrum. Thus, it is possible to adjust in which frequency band or in which frequency range it should be attenuated, in particular whether it should be attenuated in one or more narrow spectra, in several frequency bands or over a large coherent frequency range. This selection can be made by determining the sizing (s) of the chambers. In particular, the chambers and / or the openings may be dimensioned so that selectively certain frequency ranges of the sound are damped. By providing chambers of different sizes and / or openings narrowband frequency ranges are deliberately damped. As a result, a desired noise characteristic can be generated. In addition, increasingly occurring resonant vibrations can be filtered out, ie the damping characteristic can be tuned to the excitation spectrum of the engine.

The device is preferably formed in one piece. As a result, the production and installation are relatively easy and inexpensive.

In particular, the device consists of thermoplastic material. Polyphenylene sulfide (PPS), polyamide composite, polypropylene composite, polyurethane and similar materials may be used by way of example. The materials may include a proportion of glass fiber to increase the temperature resistance and durability against long term temperature exposure. Alternatively, the device may also consist of an elastomer, in particular a thermoplastic elastomer, rubber or rubber. As a simple manufacturing process, e.g. an injection molding in question.

The wall of the device for sound damping preferably has a substantially tubular cross-section. Thus, the device for insertion or insertion in a conduit, for example in the air supply line, adapted. It thus forms a kind of lining in a certain section of the pipe.

However, the chambers may be closed to the outside, however. This means that the chambers are not only closed when inserted into the line, but already an insert is provided with closed to the outside chambers.

Alternatively, at least a part of the chambers has an outwardly open side. Only when inserting into a line are the

Chambers closed by the conduit wall to the outside. The outer edges of the webs are pressed against the wall of the pipe and thus close the chambers more or less. The chambers are then in communication with the environment only via the opening to the flow area.

The device for soundproofing is particularly adapted to be used in a duct so that a portion of the inside of the boundary wall of the duct covers the open sides of the chambers. The chambers thus form in the installed state completed cavities, which act as Helmholtz resonators. As already stated, the outer edges of the webs are pressed against the boundary wall of the duct. A perfect contact between all the webs and the inside of the boundary wall of the duct is not essential for the success of the invention.

The device is formed flat in a preferred embodiment and the wall is arranged in a non-installed component substantially in a plane. In this way, the production can be further simplified. In addition, such a component can be stored to save space.

The device just described may be at least one

Have connecting portion which is formed so that at least two adjacent areas of the device can be adjusted at an angle to each other. When installing the flat device must be able to be applied to the inside of the duct. This can be done especially by bending points or hinges. It must be provided so many connecting portions that a satisfactory adaptation of the device to the shape of the inner wall of the duct is possible. It is both a plastic and elastic deformation of the connecting portions possible. The insertion takes place in the case of a manufactured as a flat part insert by bending the connecting portions to form a jacket portion, which is approximately the inside of the line section, in which the part is to be imported corresponds to. Thereafter, the insert is pushed into the line.

Alternatively, the device may be formed as a substantially flexible component, such as a mat. For example, if the device consists of an elastomer, then the flat-shaped component can be readily used in differently formed ducts. If it is flexible enough, so bent line sections prevent the insertion of the insert, which takes place as described in the last section, not. The scope of the device as an insert is thus increased. In particular, the component may be used as a liner equipped with an absorber of a portion of the duct.

The device should therefore be suitable in particular for insertion into a pipe, in particular in a curved tube, from the outside, wherein at least a part of the outside of the introduced into the tube device rests by exerting a certain pressure on the inner wall of the tube , This pressure can be relatively low. It only has to ensure a relatively secure hold of the device in a line, i. the outer shape of the device and the interior of the conduit section intended for insertion of the device must be coordinated.

The device may further include a connector for connecting the

Include device to a corresponding connection point in the engine area. For example, the connection part can extend integrally on the section of the device intended for soundproofing. The device is then brought so far into a line during insertion that the connecting part protrudes from the opening of the line and thus allows connection to another connection point, for example to the outlet of an air filter, the input to the turbocharger or a connecting pipe. The connection part can replace in this way a rubber grommet, which would otherwise have to be additionally connected to the opening portion of the line. In addition, it can fulfill sealing functions on connecting sections or the Decoupling serve between two components, which would otherwise also require the use of separate parts. This solution using a Monobauteils invention is inexpensive and the assembly of individual components is easy to perform.

The stated object is also achieved by a device for conducting a fluid, in particular for supplying air to an internal combustion engine, comprising a duct and a device for sound damping, as described above. The above-described device for soundproofing serves in particular as an insert for the duct. The device for conducting the fluid can be obtained in particular by retrofitting an already existing duct with the device for sound damping.

In particular, the duct may be adapted to receive the device for sound attenuation in a portion of the duct.

The inside of the duct in the region of the section preferably has a bulge for receiving the device for sound attenuation. For this purpose, for example, a niche can be formed in the duct, in which the device can be used for soundproofing. The niche and the design of the external shape of the sound attenuation device may be specially adapted to each other.

In particular, the flow cross-section for the fluid in the transition region from the duct to the demarcated from the wall flow range of the device for sound damping does not change or not essential, at least continuously and not leaps and bounds. A sudden change in the flow cross-section would have the disadvantage that the flow resistance for the fluid increased and thus unwanted energy losses and turbulence would occur. By mutual adaptation of the duct and the device for soundproofing, despite the equipment or retrofitting with a silencer a streamlined, the optimal contour following flow cross section over the entire flow distance can be achieved. Further features and advantages of the subject of the invention will become apparent from the following description of specific embodiments. Show it:

Fig. 1 is a perspective view of an inventive

Shock damping device;

Fig. 2 is an enlarged view of a detail of

Sound attenuation device;

Fig. 3 shows the device according to the invention from Fig. 1 in another

Perspective;

FIG. 4 shows an intake pipe with integrated silencer, partly cut away; FIG. and

Fig. 5 shows the opening area of the intake pipe with integrated

Silencer.

In Fig. 1, the inventive device for sound damping, hereinafter referred to as silencer 1, shown. The muffler 1 in the embodiment is a one-piece insert formed separately from an intake pipe. This has the advantage that the muffler 1 and the intake pipe of an internal combustion engine or a turbocharger, in which the insert part is to be used, can be manufactured independently of each other. In particular, it is possible to retrofit an existing air duct with a correspondingly adapted silencer 1 in a simple manner. In addition, easy handling of the component during installation and a cheap production is possible.

The muffler 1 is preferably made of plastic. It has been shown that plastic parts are not only simple and inexpensive to produce, but now also materials are available that meet the required mechanical, thermal and acoustic requirements perfectly. For example, the component may be made of thermoplastics having suitable characteristics of wear, heat resistance and processability. As suitable materials, for example, polyphenylene sulfide (PPS), polyamide or polypropylene composites, which, if necessary Fiberglass content can be added. An alternative material in the manufacture of the monobody may be an elastomer.

The outer shape of the muffler 1 is determined essentially by the formation of the portion of a pipe into which the muffler 1 is to be used. In particular, the outer shape of the muffler 1 can be adapted to existing lines, so that the lines can be retrofitted with the muffler 1.

The front side of the muffler 1 has in the present

Embodiment, a substantially circular opening 2 with a diameter d, which is bounded by the flange 8. The diameter d may correspond to the diameter of an outlet opening of an air filter or the diameter of an upstream or adjoining channel section in order to avoid losses due to flow resistance as far as possible. Overall, the influence of the muffler 1 on the flow and thus the pressure loss along the flow path should be minimized.

The adjoining the opening 2 flow range for the air or the exhaust gases is limited by a wall 3. When flowing through a fluid, such as air or exhaust gas through the muffler 1, the inside of the wall 3 of the muffler 1 act as a resonator, which can come to the formation of standing sound waves. In order to achieve soundproofing and / or soundproofing, the silencer 1 has a multiplicity of chambers 4, which are delimited by the outside of the wall 3 and by radially extending webs 5 and webs 6 extending perpendicularly thereto in the longitudinal direction. As is clear from FIG. 1, the webs 5, 6 form a kind of lattice structure on the outer surface of the wall 3. The chambers 4 are open in the insert part 1 to the outside, however, are closed when used in the intake pipe through the boundary wall from the outside, so that defined cavities arise. The chambers 4 can then be used as Helmholtz resonators for noise mitigating effect. Alternatively, however, chambers 4 which have already been closed to the outside could be formed in the muffler 1.

Each of the chambers 4 communicates with the interior of the muffler via an opening 7 in connection. This is clear from Fig. 2 can be seen.

Based on Fig. 2, which shows an enlarged section of the muffler 1, the operation of the muffler will be explained.

Each of the chambers 4 forms a cavity through the outer

Surface of the wall 3 as a base and by the webs 5, 6 is limited. The volume of the cavities is determined by the distances between the webs 5, 6 and their height. The cavities communicate with the opening 7 with the interior, i. with the flow range, the muffler 1 in conjunction. The cavities then act as Helmholtz resonators with built-silencer. The chambers 4 themselves are usually not flowed through by the air. As an alternative, the chambers 4 can already be manufactured as cavities of the muffler 1 which are closed on the outside during production.

The absorption frequency of a Helmholtz resonator depends essentially on the size of the chambers 4 and on the dimensioning of the openings 7. In this way, selectively selected frequency bands can be attenuated. This offers the possibility to specifically select and adjust the noise characteristics of the frequency spectrum not absorbed by the muffler. On the other hand, can be attenuated by the design of different opening cross-sections of the openings 7 and / or by the use of different sizes of the chambers 4 broadband to achieve the fullest possible sound attenuation. The wall 3 of the muffler 1 with the openings 7 substantially forms a circularly curved perforated plate, which is arranged at a certain distance from the inner wall of the channel in which the muffler 1 is to be arranged. The distance is essentially determined by the height of the webs 5, 6. In operation, each of the Helmholtz resonators acts narrowband by exciting vibrations that produce internal losses. The greatest effect is the damping effect of the HeimholtΣ resonator in ResonanΣfall. The resonance volume determining quantities, namely height, width and depth of the resonance chambers 4 are smaller than the wavelengths of the sound waves to be damped.

Fig. 3 shows the muffler 1 according to the invention from a different perspective. The second opening 12 of the flow area of the muffler 1, which points in the illustration of FIG. 1 in the sheet plane, is bounded by a second flange 11.

In the present case, the muffler is formed or its openings are arranged so that the muffler can be used in the region of a line curvature. The gases entering through the first opening 2 flow through the flow area defined by the wall 3 and exit the silencer 1 in one or more other directions R2 as the inflow direction R1 through the second opening 12. However, the invention should not be limited to this embodiment, but also include, for example, muffler with a constant flow direction of the fluid.

Fig. 4 shows a section of an intake pipe 9, which has a portion 10 in which a silencer 1 as shown in Fig. 1 is arranged. The bulge in section 10 is created by providing an additional, beyond the average flow cross-section of the intake manifold 9 extending cavity into which the muffler 1 is inserted. The portion 10 of the intake manifold 9 and the muffler 1 are matched in shape to each other so that the muffler 1 can be used exactly in the cavity provided in addition to the flow volume. The diameter d (see Fig. 1) of the flow area of the muffler 1 is the same size as the inner diameter of the adjoining the section 10 in the region 10 ^* pipe section. The same applies to the other opening of the muffler in the range of 10 ^", thereby increasing the flow resistance with respect to one not with a

Silencer equipped intake manifold prevents. Of the Flow range of the muffler 1 can therefore aerodynamically follow the contours of the flow cross-section of the intake pipe in the transitional areas 10 ', 10 ", which is a flow-friendly, space-saving and simple and inexpensive hersteiibare solution available at retrofitting even when retrofitting.

The muffler 1 is held securely by a contact of the flange 8 at a stop of the intake pipe 9 and by abutment against a second stop in the region of the rear opening in its use position.

In particular, the intake pipe 9 is an air intake pipe arranged between the air filter and the turbocharger. However, the invention is not limited to this application. Rather, the silencer according to the invention in all possible lines, which are traversed by a fluid, such as air or exhaust gas, are used. For example, the exhaust pipe of an internal combustion engine can be equipped with the silencer 1 according to the invention.

The intake pipe 9 may be made of a suitable plastic. In principle, a one-piece design of the muffler 1 with the intake pipe 9 is conceivable.

5 shows the opening region of the intake pipe 9 with inserted silencer. The openings 7 of the muffler 1 connect the flow area of the muffler 1 with the underlying chambers 4, which act as Helmholtz resonators. In the present example, the muffler 1 is arranged in the region of a curvature of the tube. However, in the context of the invention, the muffler 1 can extend into any region of the intake pipe 9 and over any section 10.

Claims

claims

1. A device (1) for sound attenuation of the sound generated by a fluid in a duct, in particular the sound generated in a suction duct of an internal combustion engine, comprising a wall (3), the inside of which delimits a flow area for the fluid, characterized in that the device For noise attenuation on an outer side a plurality of chambers (4), which are in communication with the flow area.

2. Apparatus according to claim 1, characterized in that each of the chambers (4) with the flow area via at least one opening (7) is in communication.

3. Apparatus according to claim 1 or 2, characterized in that the chambers (4) from the outside of the wall (3) and on the outside of the wall (3) formed webs (5, 6, 8) are limited.

4. Apparatus according to claim 3, characterized in that the webs (5, 6, 8) are aligned substantially perpendicular or parallel to the main flow direction of the fluid.

5. Device according to one of the preceding claims, characterized in that the chambers (4) act in the operating state as Helmholtz resonators.

6. Device according to one of the preceding claims 2 to 5, characterized in that

Chambers (4) with different volumes and / or openings (7) are provided with different opening cross-sections.

7. Device according to one of the preceding claims 2 to 6, characterized in that the chambers (4) and / or the openings (7) are dimensioned so that selectively certain frequency ranges of the sound are damped.

8. Device according to one of the preceding claims, characterized in that the device (1) is integrally formed.

9. Device according to one of the preceding claims, characterized in that the device (1) consists of thermoplastic material which comprises in particular polyphenylene sulfide (PPS), polyamide composite material, polypropylene composite material, polyurethane and / or a glass fiber content.

10. Device according to one of the preceding Ansprüchel to 8, characterized in that the device (1) consists of an elastomer, in particular a thermoplastic elastomer.

11. Device according to one of the preceding claims, characterized in that the wall (3) of the device (1) for sound damping has a substantially tubular cross-section.

12. Device according to one of the preceding claims, characterized in that the chambers (4) are closed towards the outside.

13. Device according to one of the preceding claims, characterized in that at least a part of the chambers (4) has an outwardly open side.

14. The apparatus according to claim 13, characterized in that the device (1) is adapted to the sound attenuation, so to be inserted into a duct that a region of the inside of the boundary wall of the duct covering the open sides of the chambers (4).

15. Device according to one of the preceding claims, characterized in that the device (1) is flat and the wall (3) is substantially disposed in a plane.

16. The device according to claim 15, characterized in that the device (1) has at least one connecting portion which is formed so that at least two adjacent regions of the device (1) can be adjusted at an angle to each other.

17. The apparatus according to claim 15, characterized in that the device (1) is designed as a substantially flexible component.

18. Device according to one of the preceding claims, characterized in that the device (1) for insertion into a pipe, in particular also in a curved tube, from the outside is suitable, wherein at least a part of the outside of the inserted into the tube device ( 1) rests on the inner wall of the tube while exerting a certain pressure.

19. Device according to one of the preceding claims, characterized in that the device (1) further comprises a connection part for connecting the device to a corresponding connection point in the engine area.

20. Device for conducting a fluid, in particular for supplying air to an internal combustion engine, comprising a duct (9) and a device (1) for sound damping according to one of the preceding claims.

21. Device for conducting a fluid according to claim 19, characterized in that the duct (9) is adapted to receive the device (1) for sound attenuation in a portion (10) of the duct (9).

22. Device for conducting a fluid according to one of the preceding claims 19 or 20, characterized in that the inside of the conduit (9) in Area of the portion (10) has a bulge for receiving the device (1) for soundproofing.

23. Device for conducting a fluid according to one of the preceding claims 20 to 22, characterized in that the flow cross-section for the fluid in the transition region (10 \ 10 ") from the duct to the wall of the (3) delimited flow area of the device (1 ) does not change or continuously change to the soundproofing.