DE102008033802B4 - Suction line element for an internal combustion engine - Google Patents

Abstract

For suction-side air duct for an internal combustion engine certain, equipped with means for sound attenuation line element (1, 1 '), which means by at least one whose peripheral region at least partially performing energy absorbing, air-permeable layer (4) are formed with at least one, fulfilling a supporting function , layer (2) provided with openings (3) and consisting of an air-impermeable material, characterized in that the layer (2) is represented by a planar network of webs.

Description

The invention relates to a conduit element according to the preamble of claim 1.

It is known that the air intake pipe of an internal combustion engine due to its connection with the engine compartment pressure pulsations subject, which lead to the formation of standing waves and vibration excitations of the pipe, the air column within the pipe and adjacent components, so that there is a need, the associated sound radiation to reduce. A particularly disadvantageous sound radiation from the intake is felt out into the environment.

From the DE 10 2004 014 314 A1 is known for guiding the intake air for an internal combustion engine line element known in the circumferential direction airtight, made of PA (polyamide) or PP (polypropylene), produced by injection molding and porous, made of PP or PE (polyethylene), in one Extrusion method has produced wall sections. Based on the area ratio of the air-impermeable and the porous wall sections, which is assumed to have an average pore width of about 30 microns, the damping properties of such a conduit element can be influenced. To connect the different wall sections adhesive or welded connections or latchable connections are proposed. Due to the comparatively small pores, a vibration excitation of adjacent components of the engine compartment should also be avoided, as should intake of hot air from the engine compartment. A disadvantage of this embodiment is that the air-permeable and the air-impermeable wall sections have different strength properties, but in the operation of the internal combustion engine are exposed to their vibrations and in particular mechanically claimed equally. According to the concrete dimensioning of the wall thicknesses, this can lead to damage.

From the DE 103 39 082 A1 is an intake system for an internal combustion engine consisting of a filter housing and this input side upstream, made of spun or woven sheep wool known for the management of raw air pipe known. The sheep wool comes without treatment, for example by impregnation used and can only be equipped for stabilization with a support grid or inserted support wires. Although an effective soundproofing can be achieved with such a pipe, problems arise due to the comparatively low strength or durability of such a pipe compared to mechanical stresses of a steam jet cleaning device in a motor wash. There are weather- and pest-related decomposition risks which can limit the service life of such a pipe.

In the document JP 2000-282985 A a similar intake manifold for an internal combustion engine is described, which consists of a support structure forming a circumferentially at least partially perforated tube member which is surrounded on the outside by a existing polyethylene, shrinkage by the tubular element in connection standing knitted fabric. This results in similar problems to those of the document DE 103 39 082 A1 ,

That from the document JP S62-174560 A known suction tube shows a multi-layer wall structure, the radially outer and inner layers of a porous material, between which there is a sound absorbing material. Between the latter material and the porous layers is a filter material. This intake pipe thus has a relatively complicated wall structure.

From the document DE 32 34 633 A1 an air filter for an internal combustion engine is known, which has a conically widening in the direction of the filter inlet pipe, which is provided in the input region with two spaced-apart, concentric to the pipe axis arrangement of holes. The total area of the bores of each array is dimensioned according to the 0.02 to 0.04 times the value of the mean cross-sectional area of the inlet pipe, and the distance of the two arrays from the inlet area should be, for example, 0.14 to 0.26 times the total length of the inlet Inlet pipe correspond. In this way, an attenuation of the intake noise, in particular in a frequency range of 315 Hz to 1600 Hz to be achieved by a formation of standing waves is reduced. This known inlet pipe has been designed mainly for sound insulation purposes. According to the specific installation location within an engine compartment, a suction of heated air through said openings can not be excluded, so that the combustion conditions of the combustion chamber of the engine deteriorate due to a lower air supply.

From the document DE 34 31 078 A1 an intake pipe for an internal combustion engine is known, which consists of a porous material such. As an aluminum or ceramic sintered material or a steel mesh material which may be surrounded on the outside by a perforated steel tube for mechanical stabilization.

From the document EP 1 780 398 A1 a suction pipe is known, which consists of a flexible, inside perforated metallic pipe member which is surrounded on the outside by a fiber-forming, a thermal and an acoustic insulation forming tube, which is located within a corrugated tube over which a sufficient strength of the for a Use in engines with charging specific intake pipe is displayed. Also in this intake pipe results in a relatively complicated, inter alia, due to the end-side connection of the different pipe elements structure.

The document DE 199 43 246 B4 shows an intake manifold, which is intended for use in turbocharger equipped intake manifolds of an internal combustion engine. Here, a central, intended for gas guidance, perforated tube is surrounded on the outside with a plurality of axially successive, and this surrounding resonance chambers. This leads to a comparatively complicated, a considerable volume demanding pipe element.

Finally, from the document DE 35 31 353 C2 a further intake manifold for an internal combustion engine is known, which consists of a gas guide intended, consisting of a plastic perforated, on the outside surrounded by a material consisting of a sound absorbing material consisting of an open-cell foam tube. An outer tube surrounding the tubular element forms a support structure. In particular, due to the multi-layer structure in connection with its frontal connection to subsequent line elements results in a relatively complicated embodiment.

These known forms of intake manifolds are thus not suitable to meet all operational requirements of an internal combustion engine, to which in addition to a sufficient damping capacity a stress-resistant design form and functional aspects that affect the air flow.

It is the object of the invention to design a line element of the type described above with respect to the above-described prior art in a simple manner with regard to an improved suitability for the fulfillment of all operational requirements. This object is achieved with such an intake manifold by the features of the characterizing part of claim 1.

An energy absorbing layer and an apertured layer providing a supporting function are provided, these two layers representing at least part of the wall of the duct element. A wall element shown in this way as part of the line element may in the most general case extend over a part of the circumference of the line element and / or a part of its length. The positioning of the openings can hereby be chosen taking into account the dimensions of the line element and the frequency components to be attenuated of the overall transmitted sound spectrum. The energy absorbing layer is made of an air-permeable material whose principle of action is that irreversible energy is converted into heat, mainly by friction, wherein the supporting function fulfilling layer, apart from said openings, consists of an air-impermeable material, and wherein said Apertures part of the transmitted sound energy is coupled out and radiated into the engine compartment. Due to the support function fulfilling layer, the conduit element has a sufficient strength or mechanical resistance to withstand the stresses of a motor washing, in particular a steam cleaning device without damage. The energy-absorbing layer has such a flow resistance that, despite the openings of the layer which fulfills a support function, a significant intake of warm air into the air flow supplied to the combustion chamber of the engine is not to be feared. The apertured layer fulfills a supportive and protective function for the energy absorbing layer and is formed by a grid of lands.

The features of claims 2 and 3 are directed to alternative, viewed perpendicular to the wall of the conduit element successive arrangements of the at least one energy absorbing layer on the one hand and the at least one, a support function fulfilling layer on the other.

According to the features of claim 4, the supporting function fulfilling layer may extend over the entire length and over the entire circumference of the conduit member, wherein further said openings may be arranged uniformly distributed in the circumferential direction and in the longitudinal direction of the conduit member. Alternatively, in particular in accordance with the sound spectrum to be damped, the openings can also be distributed unevenly over the surface of this layer.

The features of claims 5 to 7 are directed to alternative embodiments of the energy absorbing layer. This may hereafter be made of a porous, open-pore foamed plastic, as consisting of fiber composites layer, for. B. in the form of felts, fleeces or wadding, or as a fabric, knitwear, etc. may be formed. As plastics, also for fibers or fabrics, PP (polypropylene), PES (polyester), PA (polyamide), PPS (polyphenylene sulfide) etc. can be used in this connection. Add fibers from natural fabrics such as wool, cotton.

The supporting function fulfilling layer may consist of a thermoplastic material according to the features of claim 8, with which a sufficient mechanical stability can be represented.

The features of claims 9 to 12 are directed to a further embodiment of the wall of the conduit member. The energy-absorbing layer is then followed by a layer consisting of an air-impermeable material, which, for example, has a membrane-like construction and can be provided with a distribution of openings. The areal distribution of these openings in the membrane may correspond to that of the supportive layer. As a result of this at least partially closed layer resulting from reflections and interference a further energy conversion and thus damping effect. Part of the sound energy transmitted through the wire is also reacted in the energy absorbing layer in this case, whereas another part passes through the openings of the outer layer into the engine compartment. Through openings in the membrane-like layer, the derivation of a part of the energy transmitted in the line element into the energy absorbing layer can be improved.

In an advantageous manner, this membrane-like layer can be made of the same material as the layer fulfilling a supporting function, that is to say consist of a thermoplastic material.

The features of claims 13 and 14 are directed to alternative further embodiments of the energy absorbing layer. This layer may then be modified in its material consistency either stepwise or continuously, for example in the direction of the inner surface of the conduit member towards a homogeneous distribution of properties to the effect that at least an approximate airtightness results on the inside. Such a layer construction can be achieved in many ways, for example by a plurality of different in their material consistency sub-layers are joined together in the context of energy-absorbing layer, by welding, gluing or otherwise. Alternatively, depending on the material nature of the energy absorbing layer, a thermal treatment aimed at densification is also contemplated. The thus resulting, for example, inside layer can in turn be formed closed or provided with a distribution of openings.

All layers of the wall structure of the line element can according to the features of claims 14 and 15 cohesively or positively connected with each other. For example, the energy-absorbing layer can be positioned in an injection mold and then a thermoplastic, the outer layer performing plastic are injected. However, there are also other, readily available to the skilled artisan common bonding techniques into consideration.

According to the features of claims 16 to 17, the outside openings of the layer fulfilling a supporting function are covered by cover plates while leaving one air gap each in the edge area. The air gap is dimensioned such that a sufficient cross-section is provided for coupling out a partial energy of the energy conducted via the line element. The cover plates covering the openings in a direction perpendicular to the surface of the conduit member provide enhanced protection of the energy absorbing layer from the stresses of engine wash. The cover plates can advantageously be formed with the same material as the outer layer of the conduit element and communicate with the latter via webs.

A further sound-absorbing effect can be achieved with the features of claim 18 in that an air gap is set up between the layer fulfilling a support function and the energy-absorbing layer.

Further modifications of the wall structure of the conduit element according to the features of claim 19 are possible, according to which, for example, the energy-absorbing layer is subdivided into sublayers leaving air gaps, and an air gap is also provided between an inner, air-impermeable layer and the energy-absorbing layer.

According to the features of claims 20 and 21, the conduit element may be subdivided in the longitudinal direction or in a cross section into segments which are detachably or non-detachably connected to one another.

The invention will be explained in more detail below with reference to the embodiment shown in the drawings. Show it:

1 a perspective view of a first embodiment of a conduit element according to the invention;

2 a perspective view of a second embodiment of a conduit element according to the invention;

3 a sectional view of the conduit element according to a sectional plane III-III of 2 ,

With 1 is in 1 designates a line element in its entirety, which serves to guide sucked, intended for the operation of an internal combustion engine air. It has, for example, a circular cross-section. The wall of the pipe element 1 consists of a radially outer layer 2 , in which, for example, evenly distributed openings 3 are formed, this layer 2 Incidentally, consists of an air-impermeable material, such as a thermoplastic material.

Radial on the inside is connected to the layer 2 a layer 4 from an air-permeable material, for. As an open porous material, a fibrous or fabric-like material or the like. The radial inside of the layer 4 is with a membrane-like, for example made of a thermoplastic plastic layer 5 overdrawn. The outer layer 2 is dimensioned with the proviso that it forms a support layer for the radially inner layers, so that the strength properties of the conduit element 1 preferably through this outer layer 2 be determined. In the layer 5 Radial, not shown in the drawing openings may be formed, the size and area distribution of the openings 3 are modeled. Through the inner, mostly smooth layer 5 a lowest possible flow resistance is provided. This layer 5 further serves to provide a retention and protection function on the substance of the layer 4 exercise. The layer 5 also serves to transmit sound energy resulting from the operation of the internal combustion engine in the form of pressure pulsations on the air-permeable layer 4 in which this energy is at least partially dissipatively implemented. According to the thickness of this layer 4 as well as their material parameters, this sound energy occurs only attenuated from the openings 3 the outer layer 2 out.

According to the surface properties and the hardness of the layer 5 Further, depending on the geometric dimensions of the interior of the conduit member 1 as well as the frequency band of the pressure pulsations, portions thereof are converted by reflection and interference.

In the in the 2 and 3 Embodiment shown are functional elements with those of 1 match, correspondingly designated, so that it can be dispensed with in this respect repeated description.

From the one who 1 This line element is different 1 in that the openings 3 the radially outer layer 2 leaving each one air gap 6 with cover plates 7 are covered. These cover plates 7 have a planar extension, that of the individual openings 3 is equal to or may be slightly larger than this dimensioned.

The between the cover plates 7 and the outer surface of the layer 2 existing air gaps 6 are dimensioned such that a substantially obstruction-free air exchange between the environment and the air-permeable layer 4 over the openings 3 is possible. The cover plates 7 are the same material as the outer layer 2 trained and stand with this over bridges 8th in firm connection with the edges of the openings 3 are integrally formed on this layer.

The mode of action in the 2 and 3 illustrated line element 1' in fact corresponds to that according to 1 but with the cover plates 7 an improved protection against the mechanical stresses of a steam jet cleaning is given.

It can be seen from the above statements that the conduit element according to the invention 1 . 1' is particularly adapted to the operating conditions of an internal combustion engine, in particular to a mounting location within an engine compartment. Due to the air-permeable layer 4 is given an effective soundproofing, without it over the openings 3 Excessive intake of hot air and its harmful influence on the available engine power. This is the adapted flow resistance of the layer 4 contrary and it is a suction over the openings 3 completely stopped when the radially innermost layer 5 is formed closed, that is exclusively fulfills the function of a membrane. The air-permeable layer 4 is arranged radially protected on both sides and undergoes in particular by the outer layer 2 a supporting effect. In this way, a sufficient for the vibration stress of a motor operation strength can be displayed.

As far as the conditions of use are comparable, such a line element can also be used generally for media management.

LIST OF REFERENCE NUMBERS

1

line element

1'

line element

2

layer

3

opening

4

layer

5

layer

6

air gap

7

cover plate

8th

web

Claims (21)

For the intake side air duct for an internal combustion engine specific, equipped with means for soundproofing line element ( 1 . 1' ), which means by at least one, the circumferential region at least partially representing energy absorbing, air-permeable layer ( 4 ) formed with at least one, a support function fulfilling, with openings ( 3 ) made of an air-impermeable material ( 2 ), characterized in that the layer ( 2 ) is represented by a planar network of webs. Conduit element ( 1 . 1' ) according to claim 1, characterized in that the layer fulfilling a supporting function ( 2 ) the energy absorbing layer ( 4 ) covered on the outside. Conduit element ( 1 . 1' ) according to claim 1, characterized in that the energy absorbing layer ( 4 ) the layer fulfilling a support function ( 2 ) covered on the outside. Conduit element ( 1 . 1' ) according to any one of claims 1 to 3, characterized in that a sound-absorbing wall construction comprising at least one energy-absorbing layer ( 4 ) and a supportive layer ( 2 ) extends over the entire circumference of the conduit element. Conduit element ( 1 . 1' ) according to one of claims 1 to 4, characterized in that the energy absorbing layer ( 4 ) is formed as a porous, open-pore foamed, consisting of a plastic layer. Conduit element ( 1 . 1' ) according to one of claims 1 to 4, characterized in that the energy absorbing layer ( 4 ) is formed as a layer composed of fiber composites. Conduit element ( 1 . 1' ) according to one of claims 1 to 6, characterized in that the energy absorbing layer ( 4 ) is formed as a fabric or the like. Conduit element ( 1 . 1' ) according to one of Claims 1 to 7, characterized in that the layer fulfilling a supporting function ( 2 ) consists of a thermoplastic material. Conduit element ( 1 . 1' ) according to one of claims 1 to 7, characterized by a further inside layer ( 5 ). Conduit element ( 1 . 1' ) according to claim 9, characterized in that the inside layer ( 5 ) is provided with openings. Conduit element ( 1 . 1' ) according to claim 9 or 10, characterized in that the inside layer ( 5 ) is formed in the manner of a membrane. Conduit element ( 1 . 1' ) according to one of claims 1 to 11, characterized in that the energy absorbing layer ( 4 ) is composed of several, differing with respect to their material parameters sub-layers. Conduit element ( 1 . 1' ) according to one of claims 1 to 11, characterized in that within the energy-absorbing layer ( 4 ) a continuous change of the material parameters is set. Conduit element ( 1 . 1' ) according to one of claims 1 to 13, characterized in that the layers ( 2 . 4 . 5 ) are at least partially materially interconnected. Conduit element ( 1 . 1' ) according to one of claims 1 to 13, characterized in that the layers ( 2 . 4 . 5 ) are at least partially positively connected with each other. Conduit element ( 1 . 1' ) according to one of claims 1 to 15, characterized in that the openings ( 3 ) of the outer layer ( 2 ) on the outside, leaving each one air gap ( 6 ) with cover plates ( 7 ) are covered. Conduit element ( 1 . 1' ) according to claim 16, characterized in that the cover plates ( 6 ) above Footbridges ( 7 ) at the boundary of the openings ( 3 ) are formed, are held. Conduit element ( 1 . 1' ) according to any one of claims 1 to 17, characterized in that between the mutually facing surfaces of the energy absorbing layer ( 4 ) and the supportive layer ( 2 ) a gap is established. Conduit element ( 1 . 1' ) according to one of claims 1 to 18, characterized in that the energy absorbing layer ( 4 ) is subdivided into sub-layers, which are each held at a distance from each other, leaving air gaps. Conduit element ( 1 . 1' ) according to one of claims 1 to 19, characterized by a longitudinal division into frontally interconnectable segments. Conduit element ( 1 . 1' ) according to one of claims 1 to 20, characterized by a transverse division into longitudinally interconnectable segments.

Images