CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Section 371 of International Application No. PCT/EP2018/085587, filed Dec. 18, 2018, which was published in the German language on Jun. 27, 2019, under International Publication No. WO 2019/121744 A1, which claims priority under 35 U.S.C. § 119(b) to German Application No. 10 2017 130 661.7, filed Dec. 20, 2017, the disclosures of each of which are incorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

The invention concerns a broad-band resonance silencer which is referred to hereinafter for simplicity as a broad-band silencer, in particular installed in an internal combustion engine, particularly preferably a motor vehicle engine, comprising an at least two-part housing, including in particular a housing lower shell and a housing upper shell. The housing has a silencer longitudinal axis and a silencer transverse axis and accommodates an exhaust gas-carrying or gas-carrying pipe which with a circumferentially surrounding pipe jacket with acoustic openings therein defines a pipe interior. The pipe forming an air passage in the installed position is enclosed by at least one damping or resonance chamber which is formed by the housing and which is operatively connected to the pipe interior by way of the acoustic openings, wherein the housing comprises axially divided two housing portions or is formed from same.

Vehicles which are becoming quieter and quieter also represent a major challenge in terms of automobile engineering, in particular the sound-intensive systems thereof, of which in particular the air induction system of the engine or a turbocharger thereof is affected. To minimise the generation of sound in an air induction system resonators are frequently used nowadays. A resonator generally comprises one or more chambers which are connected in gas-carrying relationship to an induction conduit for air. To achieve efficient sound damping and to cover a broad resonance spectrum a plurality of resonators can be provided in different configurations, which compensate for different resonance ranges.

As the parts of the induction system are nowadays frequently produced using injection moulding methods the developers are increasingly confronted with the problem of how a plurality of resonator chambers can be provided in the optimum fashion in a tight structural space.

Existing broad-band resonance silencers are predominantly in the form of multi-part systems or assemblies which are welded together and for example include outer housing portions into which pipe segments having openings are welded. What is noticeable with all existing solutions is the complexity of the shape configuration and the joining technology so that those systems frequently have to be welded as a multi-part structure. That is relatively complicated from the point of view of manufacturing technology and is also susceptible to faults. The complexity arising out of the state of the art increases manufacturing involvement and thus costs. Broad-band resonance silencers with resonators or resonance chambers subdivided by a plurality of separation walls require a relatively large amount of structural space and sometimes only have a small effective resonance volume. With those multi-part structures, a number of welding operations are usually required. Nested structures require interposed assembly steps in the welding procedure, which is also detrimental in regard to manufacturing costs. It is also difficult to implement different kinds and configurations of resonators in a broad-band resonance silencer and in that case at the same time to provide a large number of variants in a tight structural space.

The housing with the pipe arranged therein in the installed position form in the intermediate space between the inside tube and the outside housing, a damping system which extends along a system longitudinal axis or the silencer longitudinal axis, which axis however does not necessarily have to extend along a straight line, but can also be curved or bent. The individual damping chambers or resonance chambers are usually arranged to extend radially from the pipe in mutually spaced relationship along the longitudinal direction of extent of the silencer, of the overall system or damping system formed in that way.

Resonators of that kind are known for example from DE 10 2010 022 780 B4 and EP 1 176 355 A2 as well as DE 10 2015 202 851 A1, US 2008/230307 A1 and US 2005/284692 A1. US 2006/032700 A1 describes a broad-band resonance silencer having a plurality of resonance chambers separated by separation walls of a pipe insert body.

Disadvantages in the State of the Art

Although such broad-band resonance silencers already permit far-reaching absorption of the unwanted noises over a wide frequency spectrum the search is also on for possible ways of using them for even broader areas of use.

Technical Problem (Object)

Taking the above-mentioned state of the art as the basic starting point and the disadvantages involved therein the object of the invention is thus to at least partially avoid the stated disadvantages and in particular provide a noise silencer or broad-band resonance silencer for an internal combustion engine, which provides or permits a particularly broad spectrum of use for many frequencies and which even with a complicated geometry takes up as little space as possible and is easy to manufacture.

BRIEF SUMMARY OF THE INVENTION

That object is already attained by the features of the independent claims1and20; preferred but not necessary developments are recited in the appendant claims.

In the simplest embodiment the pipe is in the form of a pipe insert body, that is to say a unit which is preferably formed in one piece and which includes the pipe or pipe connection or a pipe element which can be inserted into the housing portions in the installed position, wherein the pipe includes a plurality of acoustic openings in the pipe jacket surface and wherein the pipe insert body also includes end connections for connection to adjoining pipes, conduits or the like and at least one acoustic passage. The at least one or each acoustic passage respectively has a or precisely one passage inlet opening, through which the fluid or gas flows into same and is closed at the end in order therefore to function for example as a lambda/4 or lambda/2 passage.

Preferably the housing includes two portions, namely a first housing half-shell, in particular in the form of a housing lower shell, and a second housing shell which can be fitted thereonto and which in particular is in the form of a housing upper shell.

According to a first feature according to the invention the damping chamber is subdivided into at least two resonance chambers by way of at least one insert bar, wherein the at least one insert bar is provided on the insert body in one piece therewith and wherein the insert bar also functions as position fixing means. In combination with the first feature as a further feature the at least one acoustic passage includes an inlet opening which opens directly into the pipe. The insert bar and/or at least the passage inlet of the acoustic passage are thus also part of the preferably one-piece pipe insert body. Preferably at least partial regions of the at least one or more acoustic passages are also parts of the preferably one-piece pipe insert body. Particularly preferably at least partial regions of the at least one or more acoustic passages are part of the preferably one-piece pipe insert body and/or one or more complete acoustic passages are part of the preferably one-piece pipe insert body. If in relation to a given acoustic passage only a partial region thereof is part of the preferably one-piece pipe insert body then the other partial region of the respective acoustic passage, in order to complete same, is preferably formed by the housing or one of the housing portions. The respective ‘partial region’ of the acoustic passage is in that case a respective wall region of the acoustic passage, including the wall region which closes the passage end opposite to the passage inlet opening. The partial regions of a wall of an acoustic passage which are formed by the pipe insert body and a housing portion on the other hand are preferably welded together. That provides that the broad-band resonance silencer is particularly simple in structure and particularly easy to manufacture, more specifically by inserting the pipe insert body into one of the housing portions and closing or assembling the preferably two-part housing. At the same time the broad-band resonance silencer has improved sound damping as it includes a broad-band resonator and at the same time acoustic passages for additional and particularly effective damping of specific frequencies, wherein both damping functions are integrated on the pipe insert body.

The invention therefore provides a solution to the problem involved, namely besides broad-band damping by means of the at least one or more damping chambers, providing compensation for at least one or various frequencies by the at least one or more acoustic passages of differing lengths and differing geometries in a particularly small structural space in order in that way to compensate for or intercept at least one or various additional frequency ranges in the one or different acoustic passages corresponding to the frequencies, wherein the specific geometrical configuration of an acoustic passage or a plurality thereof, for example in length and diameter, can be determined by the man skilled in the art adapted to the frequencies to be compensated. In that way noises are compensated in a frequency range of any size, by virtue of a suitable configuration of the acoustic passage or a plurality thereof, in addition to the broad-band damping action. Preferred frequency ranges are between 200 and 800 Hz, in which respect however other frequency ranges also certainly lie in the area of the possible. Thus for example a given acoustic passage can be designed for the range of 200 Hz, an acoustic passage which is connected thereto or is separate can be designed for the frequency range of 300 Hz and a further acoustic passage can be designed for the frequency range of 400 to 600 Hz or even up to 800 Hz. According to the invention the acoustic passages, if there are a plurality thereof, are therefore of varying lengths and geometries to compensate or intercept the different frequency ranges.

The damping chamber can be subdivided by at least one insert bar into a plurality of resonance chambers or sub-chambers which for example are arranged to extend successively along the silencer longitudinal axis. The respective insert bar thus acts as a separation wall to separate the adjacent resonance chambers from each other. Separation of the resonance chambers by the respective insert bar is respectively effected at least substantially in gas-tight relationship, in which respect a low leakage rate in relation to a gas exchange between adjacent resonance chambers is acceptable if thereby the noise-damping function of the respective resonance chamber is not substantially impaired. The respective insert bar is preferably fixed to the pipe insert body or particularly preferably is formed in one piece thereon.

The broad-band resonance silencer in the form of an air duct system thus has two essential components, namely the external or accommodating housing and the pipe insert body which can be fitted therein. The pipe insert body includes the pipe which carries the fluid or air from a silencer inlet side to a silencer outlet side. Particularly preferably the broad-band resonance silencer including the further at least one acoustic passage and insert bars for separation of the resonance chambers comprises the housing shells and the pipe insert body, whereby the broad-band resonance silencer is particularly easy to manufacture. In addition this means that the broad-band resonance silencer, with a given configuration of the housing, can be adapted to different requirements of sound damping, for example differing designs of a turbocharger, precisely by using a different arrangement of the insert bars and/or different configurations of the at least one or more acoustic passages.

Generally in accordance with the invention therefore the housing can comprise more than two housing shell portions, in which respect for the sake of ease of reference the term ‘housing half-shell’ is also used instead of the term ‘housing partial shell’. More specifically however the term ‘housing half-shell’ is intended to refer to a two-part housing with two housing half-shells.

The housing which is therefore preferably in two parts is preferably of a shell-shaped configuration and preferably includes a housing lower shell and a housing upper shell which can be joined together at a separation location or separation plane in the installed position, for example by welding, preferably extending along the silencer longitudinal axis.

The pipe insert body with the at least one inset bar extending with its longitudinal direction transversely relative to the silencer longitudinal axis and at least the partial regions of at least one or more acoustic passages is preferably in one piece, which is particularly advantageous in regard to production engineering and handling when assembling the broad-band resonance silencer. Optionally the pipe insert body can also be of a multi-part nature, if the individual portions thereof are assembled to form a coherent unit so that the pipe insert body can be handled as one component and fitted into the housing shell so that then the broad-band resonance silencer can be produced by assembly to the second housing shell.

Preferably the housing portions or shells are produced using injection molding and are sealingly or gas-tightly joined together by means of welding. The pipe insert body which can be fitted into and accommodated in the housing with the air passage or pipe is open at both ends and is of a cross-section necessary for the media to flow therethrough.

According to the invention the volume or housing interior formed between the housing and the pipe or air passage forms the broad-band resonator which can also be in the form of a ‘Helmholtz resonator’, which for compensation of or covering a frequency spectrum of the greatest width, can include a plurality of sub-chambers or resonance chambers which are subdivided by insert walls or insert bars on the insert body. The sealing integrity necessary for functioning between the resonance chambers which are preferably provided in succession in the longitudinal direction can be implemented for example by a groove-and-tongue connection. Preferably provided at the housing inside is at least one groove into which the at least one insert bar which functions as a separation wall between the resonator chambers can be inserted.

The at least one acoustic passage forms a further tubular resonance volume which for example can be in the form of a lambda/4 resonator.

The acoustic passage is preferably formed at least partially or completely by at least one passage wall formed on the outside of the pipe and which is preferably part of the pipe insert body. The acoustic passage preferably respectively extends directly from the pipe.

Preferably the passage wall of the acoustic passage is arranged externally on the pipe insert body and is preferably formed in one piece thereon.

The passage wall can extend in relation to the longitudinal direction of the passage in the longitudinal direction of the silencer, whereby the passage length can vary over relatively large ranges and can thus cover individual frequencies of a greater frequency spectrum. The passage wall can also extend transversely relative to the silencer longitudinal direction, in regard to the passage longitudinal direction, whereby the geometry of the passage extent can be varied over relatively great ranges. Particularly preferably the at least one acoustic passage has a portion which extends with its longitudinal extent in the direction of the silencer longitudinal axis and a portion which extends with its longitudinal extent along the silencer transverse axis so that the passage length and thus also the frequency damped by the passage can be selected from a wide frequency range and the silencer can be adapted to different requirements.

In that respect it is also possible for the acoustic passage to extend at least portion-wise in spaced relationship from the pipe jacket forming an intermediate space between the passage and the pipe. In that way the geometry of the longitudinal extent of the passage can be practically freely selected and the passage length can vary in a wide range and can be adapted to the respective requirements.

The pipe of the pipe insert body has a plurality of acoustic openings, wherein for a resonance chamber a respective plurality of acoustic openings can be provided on the pipe. The resonance chamber is respectively formed between the pipe and the housing, wherein adjacent resonance chambers are separated from each other by the insert bars. In relation to a respective resonance chamber a respective plurality of acoustic openings are provided on the pipe (preferably more than two) which are arranged distributed around the pipe circumference and/or a plurality of acoustic openings (preferably more than two) arranged spaced from each other in the longitudinal direction of the pipe. The number and/or size of the acoustic openings, that is to say their length, width and diameter, are individually determined according to the desired frequency ranges to be damped for each chamber.

To utilize the entire volume of the damping chamber the at least one acoustic passage can also extend over a plurality of resonance chambers, in which respect it can be of any desired geometries.

Preferably the at least one acoustic passage extends along the silencer longitudinal axis and/or along the silencer transverse axis, in particular in the edge region in the proximity of or adjoining the enclosing housing. Preferably the acoustic passage extends circumferentially along the edge of the pipe insert body and therefore substantially reproduces at a spacing the edge contour of the pipe insert body. It is however in principle in accordance with the invention for the at least one acoustic passage to be of any desired geometry for the respective situation of use, for example the geometry of a screw or spiral for particularly long acoustic passages.

In a preferred embodiment the acoustic passage includes at least one passage wall, passage rib or the like which extends radially from the pipe insert body, in particular being formed in one piece thereon, which can be connected in the installed position to the adjoining housing portion to form the acoustic passage, more specifically in particular by means of a sealing connection for closing the acoustic passage. Preferably that connection is made by means of glueing, welding or the like. In that way the pipe insert body only has to be fitted into the one housing shell with positioning of the separation wall and then closed with the second housing shell. The pipe insert body can be particularly easily produced in that way, in particular also in the form of an injection molding, more specifically also in the form of a one-piece component. The passage wall can also engage at the inside into a receiving groove of suitable configuration on the inside of the housing.

Embodiments also provide that the passage wall can additionally be welded to be sealingly closed off.

Thus a corresponding number of acoustic passages or resonator passages can be easily so provided in the given space by a plurality of passage walls which in particular extend in mutually parallel juxtaposed relationship.

The at least one or the respective acoustic passages or resonator passages each have at least one or precisely one passage opening or passage inlet opening, through which an air flow or sound wave can pass from the pipe into the respective passage and is or are respectively closed at the end opposite to the passage inlet.

Different lengths of those acoustic passages and a differing geometrical configuration thus make it possible to compensate for different frequency spectra. The configuration of the passage opening in the form of a slot has proven to be particularly desirable, in which case in principle the inlet opening corresponds to the cross-section of the acoustic passage.

In general the cross-section and the length of the acoustic passage are adapted to the frequency to be compensated. The acoustic passages can be for example in the form of a lambda/4 passage or resonator or a lambda/2 passage or resonator. With a lambda/4 passage the acoustic passage has one-quarter of the wavelength to be damped so that when a sound wave passes through to the passage end and back this involves lambda/4 and thus the wave in question is damped in the pipe by superimposition of the waves. As the sound frequencies covered depend on the respective length of the acoustic passage the acoustic passages formed in that way can be of different lengths.

Preferably the outer acoustic passages which therefore extend closer to the housing wall are larger and are therefore of a greater length because they are relatively further away from the pipe of the insert body.

Embodiments include the configuration of the acoustic passage in adjoining relationship with the outer jacket surface of the pipe but also spaced from said surface so that they therefore do not have to bear directly against the pipe jacket surface.

The configuration according to the invention, as a particular advantage, gives a saving in weight and cost as well as a substantial simplification in the manufacturing process. The design configuration of the pipe with the various passages and ribs in the form of a pipe insert body provides for particularly easy assembly which also implements the fitment of a plurality of resonators involving different modes of operation in a simple system unit or assembly.

The broad-band resonance silencer according to the invention preferably comprises plastic and is preferably manufactured using an injection molding process, that is to say in the form of a multi-part injection molding.

The broad-band resonance silencer in that respect includes a plurality of and preferably two housing portions which can be connected together at a joining location to form an interior, in particular being in the form of housing half-shells which can be separated in the transverse direction of the system, that is to say radially, and include between them the gas-carrying pipe with an inlet and an outlet end at the ends thereof as well as a plurality of acoustic openings in the pipe jacket.

The at last one acoustic passage is formed by an in particular continuous passage wall which is provided between the outer circumferential surface of the pipe insert body and the housing which receives it or encloses it circumferentially in the installed position, which passage wall is preferably formed in one piece at the outside of the pipe insert body in the form of a projecting bar, being therefore closed in the installed position by the inner surface or wall of the housing.

Preferably the at least one passage wall is provided on the pipe insert body, for example being formed in one piece thereon. It is however also in accordance with the invention for the configuration to be reversed, that is to say with the passage wall being provided at the inner surface of the housing or the housing portions, which in the installed position then fits on the outer surface of the pipe insert body and thus defines the circumferentially extending acoustic passage.

To cover or compensate for different resonance ranges embodiments include a plurality of such passage walls which are provided in mutually displaced spaced relationship at the outside surface between the pipe insert body and the housing and which are thus operative for different frequency ranges. Those acoustic passages which are thus formed by the passage walls thus form further individual acoustic chambers which can therefore be designed as desired for the noises to be influenced or the oscillations to be compensated.

Embodiments include at least one separation wall or passage separation wall or boundary walls arranged in the acoustic passage or passages, which can limit the passage length as required to compensate for given frequencies. The passage separation or boundary walls can also be adapted to be subsequently inserted, for example in the form of a tongue-and-groove connection between the two components.

To enlarge the resonance spectrum to be processed embodiments provide various acoustic passages in various planes which can be connected together by way of a connecting passage, thus for example acoustic passages provided above or below each other in the silencer longitudinal direction.

Embodiments provide that the acoustic passages can be provided on different planes in displaced relationship in respect of height relative to the central longitudinal axis of the damping system, preferably in the form of circumferentially closed damping or acoustic passages. In accordance with the invention the damping system comprises housing and pipe insert body.

The individual acoustic passages preferably extend substantially transversely relative to the longitudinal direction of the system and are preferably provided circumferentially, for example substantially in a plane extending on the pipe insert body, in which respect however individual acoustic passages can be provided on different planes on the pipe insert body. Thus for example a first acoustic passage which is thus an upper passage in the installed position can include an acoustic passage which is provided on the top side of the pipe insert body and which opens by way of a connecting passage extending downwardly in particular transversely relative to the longitudinal direction of the system into a second lower acoustic passage which for example is provided circumferentially at the outer edge of the pipe insert body.

To enlarge the geometrical configuration options in a tight available space an acoustic passage can also have a blind hole which extends vertically downwardly or upwardly or from a first acoustic passage to a second acoustic passage which is arranged in displaced relationship in respect of height in relation to that first acoustic passage, wherein same preferably extends substantially transversely relative to the longitudinal direction.

That blind hole can function as a connecting passage between two acoustic passages or acoustic passage portions which for example are provided on different planes in the broad-band resonator. A still further differentiation or frequency absorption in a tight space can be achieved if an acoustic passage or a further acoustic passage is provided in at least one connecting region of a pipe end. Preferably that acoustic passage is in the form of a circular ring space which particularly preferably is provided in or at a pipe connection of the broad-band resonance silencer. That pipe connection is particularly preferably formed in one piece on the housing.

Embodiments provide between the joint partners, that is to say the insert body and the housing, position fixing means, for example in the form of insert bars on one component, which in the installed position engage into internal grooves on the corresponding other component and which thus ensure more accurate positioning of the insert body in the housing. The bars can be for example in the form of plates secured to the insert body, preferably being formed integrally thereon. Vibrations and oscillations of the bars in operation of the silencer are also prevented by the position fixing means between the insert bar and the housing. In general the insert bars end at least substantially gas-tightly with the housing interior. The ‘installed position’, as also generally in accordance with the invention, respectively relates to the position of the respective component in the broad-band resonance silencer when ready for use.

Preferably the broad-band resonance silencer includes a pipe connection at the inlet end in the flow direction and a pipe connection at the outlet end in the flow direction, for connection to the media-carrying conduits. Preferably those pipe connections are formed on the housing, more specifically in the form of connecting unions in the form of a circular ring, on to which the connecting pipes can be fitted.

At the inlet end of an acoustic passage, at the flow side, inlet openings can be provided in the pipe jacket surface of the insert body. At its inlet end therefore the respective acoustic passage has an inlet opening provided in the pipe jacket surface of the pipe of the insert body. The acoustic passage therefore respectively directly adjoins the pipe of the pipe insert body. The acoustic passage therefore extends with its passage wall directly from the pipe. The at least one or more inlet openings can be in particular in the form of slots and are preferably adapted to the size of the acoustic passage, being therefore approximately as large as the cross-section of the acoustic passage.

At its end opposite the inlet opening the respective acoustic passage is closed so that the sound wave passing into the passage is reflected back into the pipe at the passage end. The passage is therefore in the nature of a lambda/4 passage. The acoustic passage therefore has a closed and interruption-free side wall over its entire length, which is therefore at least substantially or practically completely gas-tight except for the inlet opening of the passage. If the passage wall is formed by two components, for example the pipe insert body and the housing or a housing portion, then those components are at least substantially gas-tightly assembled, particularly preferably by welding.

Embodiments provide that an acoustic passage is subdivided into two acoustic passage portions by at least one separation wall extending transversely relative to the longitudinal axis of that acoustic passage. Preferably those separation walls, for particularly simple adaptation to the respective situation of use, that is to say for simple adaptation of the length of the acoustic passage, can be inserted in connected relationship at different locations to the acoustic passage, for example for compensation of different frequencies.

The broad-band resonance silencer according to the invention is preferably arranged between a turbocharger and an air filter housing of an internal combustion engine to compensate for unwanted resonances.

In addition the invention concerns an internal combustion engine having a broad-band resonance silencer as described hereinbefore.

In the specific description hereinafter reference is made to the accompanying drawings which form a part of this description of the invention and which for illustration purposes show specific embodiments with which the invention can be carried into effect. In this respect directional terminology like for example “upward”, “downward”, “forward”, “rearward”, “front”, “rear” and so forth is used in relation to the orientations of the described Figure or Figures. As components of embodiments can be positioned in a number of differing orientations the directional terminology serves for illustration and is in no way limiting. It will be appreciated that other embodiments can be used and structural or logical modifications can be made without thereby departing from the scope of protection of the present invention. The following description is not to be interpreted in a limiting sense.

In the context of this description the terms “connected”, “joined” and “integrated” are used to describe both a direct and also an indirect connection. Identical or similar components are denoted by identical references in the Figures insofar as that is desirable.

Reference numeral lines join the reference numeral to the part in question. An arrow in contrast which does not touch any part relates to an entire unit towards which it is directed. The Figures moreover are not necessarily true to scale. To illustrate details certain regions are possibly shown on an exaggeratedly large scale. In addition the drawings can be simplified for improved clarity and do not contain every detail which is possibly present in a practical configuration. The terms “upward” and “downward” relate to the view in the Figures.

