EP1147305A1

EP1147305A1 - Admission device with a pipe section for damping the admission noise

Info

Publication number: EP1147305A1
Application number: EP99968355A
Authority: EP
Inventors: Rolf Füsser; Heinz Müller; Helmut Spannbauer
Original assignee: Filterwerk Mann and Hummel GmbH
Current assignee: Mann and Hummel GmbH
Priority date: 1999-01-26
Filing date: 1999-12-18
Publication date: 2001-10-24
Also published as: WO2000045043A1; DE19902951A1

Abstract

The invention relates to an admission device, especially for use for an internal combustion engine, which has a pipe section for damping the admission noise. Damping devices of this type are needed for damping the noises caused by ancillary components in the admission device. In order to compensate the resulting additional complexity of the device as far as possible, the invention provides solutions permitting simple production procedures and flexible adjustment to the frequency bands to be damped. For example, in an admission pipe (10) consisting of welded shells (21, 22), the welding catching edge (27) can be used for separating a resonance volume (29) if the welding catching edges form a large enough gap. This measure means, e.g. that there is no extra need for structural components, only a slightly greater material requirement. Admission acoustics can also be improved retroactively using this measure by making small changes to the casting tools for the shells (21, 22).

Description

Suction device with a line section for damping the

Intake noise

description

State of the art

The invention relates to an intake device, in particular for the use of internal combustion engines, which has a line section for damping the intake noise, according to the preamble of claims 1, 4 and 5.

Such pipe sections for use in suction devices are known. DE 196 03 979 A1 proposes z. B. before to provide the suction device with resonance tubes. These have a constant cross-section and open into the walls of the suction device. They have a characteristic length and are based on the following principle of action.

As is well known, noises can be deleted by applying sound with the same sound spectrum but with the opposite phase of oscillation. Ideally, there is a total deletion. The resonance pipes act as branch paths in the air duct system, into which the sound penetrates and, after reflection at the end of the resonance pipe, begins the return path. If the sound reaches the junction again after this detour, the source of origin there now has a time-shifted phase position, which in the best case is exactly 180 °. The phase shift depends on the wavelength of the sound to be canceled. In order to achieve a phase shift of 180 °, the Length of the resonance tube is just a quarter of the wavelength of the sound to be deleted.

Another possibility of designing sound-absorbing line sections can be found in DE 195 04 223 A1. In the figure 1 of this document, an intake pipe 2 is shown, which is surrounded by a damping component 4, whereby an annular space 3 is created. The intake pipe has openings that can be designed as holes 7. The muffler described is equipped with connecting sleeves and can be installed in a suction device as a line section in this way.

This silencer acts as a shunt resonator. The holes 7 form its necks and the annular space 3 its volume. An oscillatory system is created which is connected to the line section via the holes. The vibration processes generated by the shunt resonator superimpose the vibration behavior in the suction device, as a result of which noise reduction can be achieved. By providing several openings of different sizes, a broadband effect can be achieved, i. H. that the noise reduction is not only effective for a selected frequency.

Even for resonance pipes, the attenuated or canceled frequency band can be enlarged within narrow limits. Here DE 196 03 979 A1 proposes that the bottom of these resonance pipes, for. B. tapered. This means that the resonance tube no longer has a characteristic length but a length range. As a result, the effect of the resonance tube is extended to a narrow frequency band.

In the intake devices of modern motor vehicles, however, ancillary units, such as. B. exhaust gas turbochargers, secondary air pumps or secondary air loaders, which represent additional noise sources in the environment of the internal combustion engine. The composition of these noises differs from that of the reciprocating engine primarily in that their high Energy components are in a frequency range above 1,000 Hertz. Around

To effectively prevent noise from spreading, broadband attenuation near the source is necessary. Conventional resonance pipes are not suitable for this because the damped frequency band for an effective one

Noise reduction is too small. You could now have a variety of

Arrange the resonance pipes, but this would mean a lot of construction. However, this cannot be operated for economic reasons, since this is a damping effort that is incurred in addition to the damping measures for the internal combustion engine.

Another possibility would be to arrange additional shunt resonators. However, this also means additional structural effort. The resonator volume must be created by at least one housing, which must either be additionally fastened in the engine compartment or integrated into the intake device. For the integration of the shunt resonator, DE 195 04 223 A1 suggests arranging it as an annular space around the line cut. But this design also means a significant structural effort. Finally, the tube must be placed in this annulus, this problem can only be solved by additional assembly steps and additional components.

The object is therefore to provide a damping device for suction devices which is simple in construction and economical to manufacture and can be easily adapted to the frequency spectrum to be damped in the application. This object is solved by the features of claims 1, 4 and 5.

Advantages of the invention

The suction device according to the invention has a line section through which the suction medium flows and which is connected to at least one volume forming a resonance tube. The resonance tube is like this formed that it forms a common wall section with the line section. Advantages for such a design result first of all from savings in terms of the installation space required. The resonance pipes are in direct contact with the line section and do not protrude into the engine compartment at right angles to the line section. This creates greater design freedom for the intake device and its adaptation to the engine compartment. Subsequent attachment of resonance tubes designed in this way is also still conceivable. The common wall section also saves material. This results in a weight saving that z. B. has a positive effect on the energy consumption of the motor vehicle.

According to an expedient embodiment of the inventive concept, the line section and the resonance tube essentially consist of an extruded profile, which is made in particular of plastic. This extruded profile can be deflected depending on the application and provided with end pieces at the ends. These end pieces have the task of connecting the line section to the rest of the suction device. At the same time, the end pieces are used to close the resonance pipes at their ends and to connect them to the line section at the beginning. The end pieces can also be formed as part of the adjoining elements of the suction device. A connection between the extruded profile and end pieces can, for. B. by a welded connection or by an adhesive connection. The damping characteristics of the line section can be influenced in a simple manner by varying the length of the extruded profile. The two end pieces can be kept unchanged. In addition, it is possible to provide, in addition to the end pieces, intermediate pieces which enable the connection of two line sections, formed from the extruded profile.

Another embodiment of the invention provides that the line section and the resonance tube are formed from shells and inserts. It is Z. B. conceivable to construct the line section from two half-shells, the outer contour of the resonance tube being introduced into these shells. The insert can then z. B. be positioned by vibration welding in the shell forming the resonance tube so that it forms the common wall portion, leaving an opening for connecting the two volumes. Instead of welded connections, snap connections or adhesive connections are equally conceivable. Instead of the insert part, a part forming the outer wall of the resonance tube can also be used, which part can be placed on the line section from the outside. The line section then does not have to be manufactured using multi-shell technology.

An alternative solution is to be seen in the fact that the line section for damping the intake noise has a connected volume which is separated from the line section in the region of two welded housing shells by the welded lip. In this case, the line section does not have to be through which fluid flows. It can e.g. B. is also a resonance tube, which is made in two-shell technology. A further volume is then partitioned off from this with the aid of the welding catch edge. The volume must be connected to the line section. This is done through openings that are created by an appropriate design of the welding lip. The rib forming the welding catch edge is regularly integrated into one of the shells to be welded. At the end of this rib there is a narrow gap towards the other shell. If the volume behind the welding lip is to be used, this gap can be deliberately chosen so wide that there is an acoustic coupling of the volume with the line section. As an alternative to a wider gap, the welding lip can also be broken through different openings. Depending on the design of the opening or the gap, specific acoustic effects can be achieved. Both the effects of a resonance tube and the effects of a shunt resonator can be used. If the gap dimension is increased to form the opening, this has the additional advantage that the requirements on the component tolerances are reduced. Broadband damping is achieved by providing the gap. In terms of design, there is no additional effort, since the weld lip is necessary to improve the surface properties of the inner pipe walls, which are formed by the shells. Is that through the The volume of the welded rim provided in a resonance tube can thus reduce the resonance frequency of this tube and expand its effect on a broadband frequency spectrum.

A further alternative solution provides for the volume which is connected to the line section through at least one opening to be accommodated in an annular space surrounding the line section, the opening being formed by a slot which runs along a division between the individual parts forming the line sections . The slot along the division can be easily manufactured. He can e.g. B. in injection molds for the manufacture of the individual parts. The slot can run in such a way that all the volumes in the annular space are connected to the line section via this opening. The annulus need not necessarily be circular; just as little as the line section itself. The accommodation of the slot at the edge of a mold has the further advantage that its geometry can be easily changed by modifying these molds. It can e.g. B. in the edge region of the form inserts are provided, which are determining for the geometry of the slot and are simply replaced to implement different slot geometries. A new slot geometry then only requires the effort of a new insert, not an entire new mold.

A particularly advantageous embodiment of the invention provides that the slot runs around in the wall of the line section. In this way, a transverse division of the line section can be achieved, which results in a pot-like structure of the molds for the individual parts of the line section. With this design, the wall section forming the annular volume can also be provided in the two molds. This creates a flange-like interface of the outer walls of the annular volume, the z. B. can be glued, welded or screwed together. The walls forming the line section are made somewhat shorter, so that a gap remains between these walls by connecting the individual parts. This gap forms the opening. The parting plane that forms the gap must do not stand at right angles to the pipe wall. However, this is the most streamlined variant. However, any division is conceivable, which does not even have to lie in one plane.

An advantageous embodiment of the invention provides for the volumes in the annular space to be designed as a resonance tube. For this purpose, it is necessary to adapt the width b of the slot essentially to the radial height h of the annular space and to provide the cross-sectional areas of the tube volumes located in the annular space with a cross-sectional area of approximately h ² . This creates the constant cross-sectional area required for a resonance tube and an access corresponding to this cross-sectional area via the slot with the width h.

It is advantageous to provide at least one of the tube volumes with an average length of 85 mm. This is suitable for weakening or canceling out a vibration with a wavelength of 4 times, i.e. 340 mm. This wavelength corresponds to the 1000 Hertz tone component, which - as described above - is generated by additional noise sources in the intake device. A variation of further tube volumes around the length of 85 mm then produces the effect of broadband attenuation in this frequency range. By providing the tube volumes in the annular space, a material-saving and inexpensive geometric configuration is achieved. It is also possible to provide several pipes of the same average length in order to produce particularly strong attenuation for certain frequencies. The average length of the pipes is therefore mentioned because the pipe end does not necessarily have to be at right angles to the walls of the resonance pipe. Only in this case would the pipe length be specified exactly. In the other cases, the mean pipe length is calculated as the arithmetic mean of all pipe lengths over the cross section.

According to a favorable embodiment of the invention, the area left free by the slot essentially corresponds to the cross-sectional area of the line section. This requirement can also be combined with the previously mentioned design principle that b = h. The advantage of the slot area chosen in this way is a balance of the interaction between the Annular volume and the intake air flowing through the line section.

It is advantageous to choose the line section as a circular cross section, which is surrounded by a circular cross section of the annular space. The tube volumes can then be formed as circular ring segments by pulling radial walls between the inner and outer ring walls of the annular space. Circular cross-sections have the optimal ratio between cross-sectional area and wall area. As a result, flow losses in the tube and the cost of materials for its production can be minimized. In addition, a circular design has the advantage of an improved look.

In the division between the two elements forming the line section and the annular space, which simultaneously form the connection parts to the rest of the suction device, a third part can advantageously be arranged as an intermediate piece. This extends into the interior of the assembly into the two connection parts and thereby generates additional tube volumes. There is then no longer a slot in the division between the two connection parts, but rather a plurality of slots which are formed by the ends of the intermediate piece and the ends of the wall of the line section in the connection parts.

In particular when using an intermediate piece, but also in the two-part design of the line section, it is conceivable to provide a plurality of annular spaces which are nested within one another. The statements already made apply to these. A slot must then also be provided in the walls between each two nested annular spaces. In this way, an additional number of tube volumes can be formed.

Tube volumes generally mean the volumes formed in the annular space, in particular the circular ring segments in the case of an annular cross section. These can have any cross section, the cross section of these tube volumes being able to exceed h ² by far. If this is the case, the volume thus formed tends to follow the damping principle of a shunt resonator. On In this way, broadband damping can be achieved with the proposed component geometry on the basis of both damping effects (resonance tube and shunt resonator). The transition between these two effects is fluid. In addition to the variation of the volume, a variation of the slot width b can also be selected as an influencing factor.

Since the tube volumes are directly adjacent in the ring volume and are connected to the line section by the same slot, undesired coupling effects can occur between the individual volumes. These can be avoided in individual cases by attaching covers to the front of the slot-forming walls, which partially cover the slot. These can e.g. B. be made of rubber and glued or vulcanized. It is possible to determine the optimal damping form for a given vibration spectrum through experiments or to make changes afterwards. If a certain design with covers is used as a series part, it is also possible to provide these in the molds. This can be achieved in particular through mold inserts, the basic shape remaining the same for all different damper variants and only the inserts being replaced.

A modification of the invention provides that the components described do not produce a module which has to be introduced into the suction device, but rather that the module-forming components are at least partially integrated into components of the suction device. So z. B. conceivable to provide one of the end parts at the outlet of an air filter housing, and the standard module parts can be combined with these. This makes it possible to achieve a further saving in weight and to avoid manufacturing and assembly outlay in large series production.

These and further features of preferred developments of the invention are evident from the claims and also from the description and the drawings, the individual features in each case individually or in groups in the form of sub-combinations in the embodiment of the invention and on be realized in other areas and can represent advantageous and protectable versions for which protection is claimed here.

drawing

Further details of the invention are described in the drawings using schematic exemplary embodiments. Show here

1 shows the cross section through an extruded profile for a

Line section, which volumes are connected for the formation of resonance tubes,

Figure 2 shows the section A - A of Figure 1, with the front of the

Extruded profile a connector is applied and the representation according to Figure 1 is characterized by the section B - B,

Figure 3 shows the longitudinal section through a line section consisting of two

Shells and an insert is formed,

FIG. 4 shows the cross section through a line section which is welded lengthwise, a volume being formed by the weld lip,

Figure 5 shows the arrangement of a housed in the weld rim

Volume in a resonance tube, this being shown in longitudinal section,

6 shows a broadband damper consisting of two connecting parts, the volumes being accommodated in an annular space which is connected to the line section by a slot, 7 shows the top view C - C according to FIG. 6, with covers on the

End face of the connecting part are applied,

Figure 8 shows a broadband damper consisting of a connector, an intermediate piece and a connector integrated in a component of the suction device and

Figure 9 shows the schematically illustrated longitudinal section of an arrangement of two annular spaces in a line section, the two annular spaces being formed by an intermediate piece.

Description of the embodiments

FIG. 1 shows a line section 10 which is suitable for forming volumes in the form of resonance tubes 11. The resonance tubes have a common wall section 13 with a main cross-section 12 of the line section 10 through which the intake air flows. The extruded profile 14 can be made of plastic. Commercial multi-chamber profiles can also be used as semi-finished products.

FIG. 2 shows how the extruded profile 14 can be provided with a connecting piece 15. The connector is glued to the extruded profile and has a flange area 16 for connection to the rest of the intake tract. For the two resonance tubes 11 of the extruded profile 14, the connecting piece has a lid area 17 and an opening area 18. It is connected to the extruded profile in such a way that the lid area 17 closes the one resonance tube and the opening area 18 forms an opening 19 in cooperation with the extruded profile has the same cross section as the resonance tube. On the opposite side of the extruded profile, a part identical to the connector 15 can be turned by 180 ° (not shown). In this way, two resonance tubes of the same length are formed.

FIG. 3 shows a line section 10 which is manufactured using multi-shell technology. The individual shells are glued or welded together. A shape division 20 can be seen, which is located between an upper shell 21 and a lower shell 22. A recess 23 forming the resonance tube is introduced into the lower shell, which is closed except for the opening 19 with a glued-in insert 24. The insert 19 thus represents the common wall section 13. The resonance tube formed in the recess 23 has the same cross section as the opening 19.

FIG. 4 shows a line section 10 which is vibration-welded via welding shoulders 25. In the area of the welded connection, an inner wall 26 of the line section is formed by a weld catch edge 27, which normally covers a cavity 28 located behind it, which is intended to receive a bead formed during the welding. However, the cavity can also be expanded to a resonance volume 29. In the exemplary embodiment according to FIG. 4, this is formed by the upper shell 21. The welding rim 27 is provided both in the upper shell and in the lower shell. On the side of the resonance volume 29, however, the edges of the welding catch edges 27 form a relatively wide gap, which forms the opening 19 and ensures a connection between the resonance volume and the line section. A broadband resonator is realized in this way.

FIG. 5 shows a variant in which the weld rim of a two-shell resonance tube 11 is used. Elongated holes 30 are formed in the weld rim, which enable a connection of the circumferential cavity 28 to the resonance tube 11. The resonance tube opens into a housing 31, which is designed as part of the suction device, not shown. The cavity 28 behind the welding rim 27 does not have to be increased in volume in order to act as a resonance volume. If only the gap of the welding edge in the area of the clean air line of the suction device z. B. enlarged to 1.2 mm, not only the overall noise of the suction device in the upper speed range, but also by the 4 kilohertz octave band, which is perceived by humans as unpleasant. The engine power remains unaffected by this acoustic measure. In addition, a reduction in the resonance frequencies of the suction device can also be achieved by the design measure described, which is desirable in some cases.

Figure 6 shows the section through a broadband damper. This consists of two connecting parts 32 which, for. B. can be designed as a connector 33 for connection to a hose. The two connecting parts form the main cross section 12 and an annular space 34 which surrounds the main cross section. Outer walls 35 have welding shoulders 25 so that the connecting parts can be connected to one another. The arrangement of a welding catch edge according to FIG. 4 is conceivable in this area. The annular space 34 is separated from the main cross section 12 by partition walls 36. End faces 37 of the intermediate walls 36 have an axial offset with respect to the welding shoulders 25, such that the end faces 37 form a radially circumferential slot when the connecting parts 32 are connected to one another, which connects the main cross section 12 to the annular space 34. In the annular space 34, individual tube volumes 39 are divided by radial walls 38. These are each connected to the main cross section 12 via the slot 40. The division of the annular space 34 into tubular segments 39 in the form of a ring segment can take place as desired and does not have to match in the two connecting parts. The slot 40 can be closed over parts of the circumference by covers 41.

The exact structure of the annular space can be seen in FIG. 7, which represents the supervisory level CC according to FIG. 6. The main cross section 12 and the tube volumes 39 located in the annular space, which are formed from the outer wall 25, the radial walls 38 and the intermediate wall 36, can be seen. The covers are on the end face formed in this way, which can be seen here in supervision 41, the z. B. can be made of rubber, glued. These can e.g. B. Prevent coupling effects between adjacent tube volumes. It is also possible to create a resonance chamber that is completely closed off from the adjacent tube volumes by attaching the cover to the end faces of the radial walls. This then acts as a shunt resonator, the opening 19a being divided from the slot through the cover.

FIG. 8 shows a broadband damper which works on the principle of the device according to FIG. 6. However, only one connecting part 32 with a flange area 16 is provided. The other connecting part has been replaced by a receptacle 42, which is part of the housing 31, the housing 31 belonging to the suction device, not shown. The receptacle can be connected to the connecting part. However, an intermediate piece 43 is also introduced into this connection. Like the receptacle and the connection part, this has tube volumes 39a and forms slots 40 with these parts at both ends. These run radially in the main cross section; however, the slot plane is not perpendicular to the flow direction of the main cross section, but rather at an angle. In this way, tube volumes 39 of different lengths can be generated by a straight boundary wall 44.

FIG. 9 shows the schematic representation of an alternative embodiment of the intermediate piece 43. Two nested annular spaces 34 are created by this. In this exemplary embodiment, the connection parts 32 have no tube volumes. The tube volumes 39a are formed only by the intermediate piece.

The individual parts 32, 42, 43 according to FIGS. 6 to 9 can be designed in such a way that they can be combined with one another. In this way, a modular system is created which has basic elements which can be combined using the covers 41 to form optimal broadband attenuators for the respective application. In the case of large-scale production, the shapes for the individual parts can then be adapted to a special application.

Claims

claims

1.Intake device, in particular for use in an internal combustion engine, which has a line section (10) through which the suction medium flows and which is connected to the line section with at least one volume through which there is at least one opening (19), the volume and opening in each case being a resonance tube ( 11), characterized in that the resonance tube has a common wall section (13) with the line section.

2. Suction device according to claim 1, characterized in that the line section (10) and the at least one resonance tube (11) are integrated in an extruded profile which is provided at the ends with end pieces (15), which apart from the at least one resonance tube close the openings (19) tightly.

3. Suction device according to claim 1, characterized in that the

Line section (10) and the resonance tube (11) are formed by at least two shells (21, 22) and / or inserts (24).

4. Intake device, in particular for use in an internal combustion engine, which has a line section (10) which is connected to the line section with at least one non-flowed volume via at least one opening (19), characterized in that the line section and volume consist of at least two welded shells (21, 22) exist and the volume is divided by a welding lip (27) from the line section.

5. suction device; In particular for use in an internal combustion engine which has a line section (10) through which the suction medium flows and which is connected to the line section with at least one volume through which there is no flow through at least one opening, characterized in that the volumes in at least one line section (10 ) surrounding annular space (34) and the opening is formed by a slot (40) which runs along the division between individual parts (32, 42, 43) of the line section (10).

6. Suction device according to claim 5, characterized in that the slot (40) in the wall of the line section (10) rotates.

7. Suction device according to one of claims 5 or 6, characterized in that the width b of the slot (40) substantially corresponds to the height h of the annular space (34) and arranged in the annular space at least one tube volume (39a) with a cross-sectional area of h ² is.

8. Suction device according to claim 7, characterized in that at least one tube volume (39a) has an average length of 85 mm.

9. Suction device according to one of claims 5 to 8, characterized in that the area of the slot (40) corresponds substantially to the cross-sectional area of the line section (10).

10.Absaugvorrichtung according to any one of claims 5 to 9, characterized in that the line section (10) have a circular cross-section and the annular space (34) have a circular cross-section, the tube volumes (39 a) through radial walls (38) which the inner with the outer Connect the ring wall of the annulus, are separated from each other.

11. Suction device according to one of claims 5 to 10, characterized in that in the division of two connecting parts (32) at least one intermediate piece (43) is arranged, additional tube volumes (39a) and at least two slots (40) being formed by the intermediate piece .

12.sucking device according to one of claims 5 to 11, characterized in that covers (41) on end faces (37) of the slot-forming walls of the individual parts (32, 42, 43) are attached

13.Absaugvorrichtung according to any one of the preceding claims, characterized in that the line section (10) is at least partially integrated into a component of the suction device.