EP2913513B1 - Air intake noise damper - Google Patents

Description

The invention relates to an intake silencer for a fluid line and a heater with the intake silencer.

It is known to use auxiliary heaters in motor vehicles. To avoid noise pollution from the existing in the vehicle aggregates of the heater, it is particularly known to arrange in the intake of a fluid, such as air, mufflers, because the intake is known to be a significant source of noise in the near field of the intake of the heater, it comes in the operation of the Heater and the necessary for combustion intake of combustion air to intake noise in different frequency ranges.

In the near field of the intake mouth arise noise with predominantly low-frequency frequency components, which are caused in particular by the combustion noise of the heater. Furthermore, noises arise with predominantly higher-frequency frequency components, which are caused in particular by a fan of the heater which heats the fluid, which are comparable to a turbine noise.

As a general state of the art for information, the publications DE 10 2008 020 721 A1 and FR 2 392 228 A1genannt.

The publication DE 10 2010 049 578 A1 discloses a muffler assembly having a fluid conduit through which a fluid, in particular air, is guided. The fluid line has seen in the flow direction to a fluid drain and a fluid supply. The fluid, in particular the air, thus flows from the fluid supply to the fluid outlet. Sound propagation from an aggregate connected to the fluid outlet, such as a heater, for example, takes place in the opposite direction, which is defined as the sound emission direction. The fluid line is surrounded by a resonator arrangement which has three resonator tubes connected in series and arranged concentrically with one another. The first resonator tube of the resonator arrangement is connected in a sound-transmitting manner to the fluid line via a connection opening in a wall. Only a small fluid exchange takes place via the connection opening, since the resonator arrangement has no outflow. The silencer arrangement also has absorption devices that can be designed for different frequencies.

Also known are the publications DE 10 2012 000 806 A1 and US 5,952,625 A , each revealing a resonator system in which components for forming the respective body of the resonators can be pushed each other.

The invention is based on the object to further reduce the noise of the known muffler assemblies. Furthermore, the muffler assembly should be made compact and inexpensive and easy to manufacture. In addition, the silencer assembly should only have a low weight and be produced with low material costs.

The starting point of the invention is a silencer assembly comprising an insertion part, which is pushed in a state of assembly of the silencer assembly in a housing part, wherein the housing part has a fluid channel in which a fluid in the axial direction of the silencer assembly from an inflow opening to an outflow opening flows, and at the same time acts as a resonator tube for propagating in the fluid channel sound waves.

According to the invention, the fluid channel comprises a first channel segment which is open on both sides as an inflow channel with the inflow opening for the fluid, and a second channel segment which is open on both sides coaxially with the first channel segment as a feed channel with the outflow opening for the fluid, so that the inflow opening and the outflow opening are arranged on one side of the muffler assembly, since the fluid channel is deflected within the housing part on a side opposite the insertion part via a U-shaped connection opening, wherein in the assembled state, a closing element closes the housing part at one end, without closing the U-shaped connection opening , wherein the housing part and the insertion part before the assembled state each have an open resonator chamber for each one branched off from the fluid channel branch resonator, in the assembled state by inserting the insertion part in the Housing part are closed and sound transmitting with the functioning as a resonator tube fluid channel in operative connection.

According to the object of the invention, the noise development is substantially reduced by such a silencer assembly, wherein two resonator chambers are designed as branch resonators and a resonator tube by simple assembly, each providing the appropriate attenuation of sound waves. The muffler assembly is thereby formed very compact, wherein the resonator tube and one of the resonator chambers are applied in the housing part, while the other resonator is applied in the insertion part, wherein advantageously the two resonator chambers are formed only by the assembly.

This embodiment has the advantage that the fluid channel is designed to be longer overall, since two channel segments are formed running substantially over the entire length of the muffler assembly. Due to the deflection, there is also an increase in the sound attenuation within the fluid channel, wherein the inflow channel is also advantageously used for collecting condensate.

Advantageously, the two components, the housing part and the insertion part, interlock with one another in such a way that two components of the silencer assembly which can be produced relatively simply and inexpensively can be produced. These components also have a low weight, since only a small amount of material is necessary. The two components, the insertion part and the housing part are designed such that they are in an advantageous manner after assembly in corresponding operative connection.

In a preferred embodiment of the invention it is provided that a lying on a midpoint in the axial direction longitudinal axis of a second housing part opening, which forms a feed channel of the fluid channel, is arranged eccentrically with respect to a center of the lying in the axial direction longitudinal axis of the resonator chambers of the branch resonators. This embodiment has the advantage that within the cylindrical muffler assembly, the feed channel is not in the center of the muffler assembly, in other words, the feed channel is arranged eccentrically with respect to the mufflers of the prior art. The eccentric arrangement of the feed channel has the advantage that a larger space is available for the resonator chambers above the longitudinal axis of the feed channel, so that a larger volume is available within the resonator chambers of both branch resonators, which is available to form a plurality of sub-chambers available. The advantageous effects of these sub-chambers are explained in more detail in the description.

A further advantageous embodiment of the invention is that the housing part before the assembled state has an open resonator chamber which comprises a housing part plate extending in the axial direction, which already forms two partial chambers in the resonator chamber.

The advantage becomes particularly apparent in connection with the insertion part, which has a push-in plate, which is inserted in the assembled state into the resonator chamber designed as a branch resonator coaxially with the housing part plate extending in the axial direction. Advantageously, three partial chambers are thus formed in the assembly state in the resonator chamber, which are connected to the fluid channel via a connection opening and in turn via connection openings according to the principle of reflection of sound in conjunction.

Furthermore, in a preferred embodiment of the invention, the insertion part, which has the resonator chamber designed as a branch resonator, seen in the axial direction formed of two consecutive discs. The two successive discs are arranged at their inner diameters on a cylindrical wall, wherein the wall forms a nozzle opening of the insertion part extending in the axial direction of the muffler assembly. In the wall connecting openings are formed to two sub-chambers, which are connected via the connection openings with the fluid channel and in turn according to the principle of reflection of sound in conjunction. Advantageously, the insertion part is thus already designed as a component so that a closed resonator chamber is created by simple insertion into the housing part, which ensures a sound attenuation of propagating into the muffler assembly sound.

In an advantageous manner, first the second branch resonator, then the first branch resonator and finally the resonator tube develop their damping effect in the acoustic emission direction, the sound waves being transmitted radially into the branch resonators.

The invention will be explained below in an embodiment with reference to the accompanying drawings. The FIGS. 1 to 11 show a series type 100 of the muffler assembly. The FIGS. 12 to 14 show a prototype of the muffler assembly P100.

Figur 1

eine perspektivische Ansicht eines Gehäuseteils einer Schalldämpfer-Baugruppe;

Figur 2

eine perspektivische Ansicht eines Einschubteils der Schalldämpfer-Baugruppe;

Figur 3

eine perspektivische Ansicht eines Abschlusselementes einer SchalldämpferBaugruppe;

Figur 4

eine Ansicht in das Innere der Gehäuseteils gemäß Figur 1;

Figur 5

eine perspektivische Ansicht der Schalldämpfer-Baugruppe in ihrem Zusammenbauzustand und in ihrer bevorzugten Einbausituation;

Figur 6

einen Schnitt in einer vertikalen Ebene durch ein in Einbausituation seitlich angeordnetes Befestigungselement gemäß Figur 5, wobei die SchalldämpferBaugruppe gegenüber Figur 5 um 90° nach unten verdreht dargestellt ist;

Figur 7

einen Schnitt durch die Schalldämpfer-Baugruppe gemäß Figur 5 in einer vertikalen Ebene, durch die Mitte der Schalldämpfer-Baugruppe;

Figur 8

ein erstes Absorptionselement;

Figur 9

eine Ansicht in das Innere des Gehäuseteils ausgehend von einem in einer vertikalen Ebene verlaufenden Schnitt quer zur axialen Erstreckung der Schalldämpfer-Baugruppe im Zusammenbauzustand, wobei der Schnitt im Bereich eines zweiten segmentartigen Ausschnittes des ersten Absorptionselementes gemäß Figur 8 gelegt ist;

Figur 10

eine Ansicht in das Innere des Einschubteiles im Bereich von zwei Scheiben des Einschubteiles, mittels eines in einer vertikalen Ebene verlaufenden Schnitts gemäß Figur 6, quer zur axialen Erstreckung der Schalldämpfer-Baugruppe im Zusammenbauzustand;

Figur 11

ein zweites Absorptionselement;

Figur 12

eine Schalldämpfer-Baugruppe im Zusammenbauzustand als Prototyp (ohne Abschlusselement) in einer perspektivischen Außenansicht analog zu Figur 5;

Figur 13

einen in einer vertikalen Ebene verlaufenden Schnitt oberhalb des ersten Absorptionselementes durch den Prototypen, quer zur axialen Erstreckung der als Prototyp ausgebildeten Schalldämpfer-Baugruppe gemäß Figur 12, jedoch bei einer um circa 90° nach unten gedrehten Schalldämpfer-Baugruppe; und

Figur 14

eine Ansicht in das Innere des Gehäuseteils ausgehend von einem, in einer vertikalen Ebene verlaufenden Schnitt, quer zur axialen Erstreckung der als Prototyp ausgebildeten Schalldämpfer-Baugruppe im Zusammenbauzustand (ohne Abschlusselement) gemäß Figur 12 und 13, wobei der Schnitt im Bereich des zweiten segmentartigen Ausschnittes des ersten Absorptionselementes gelegt ist.

Show it:

FIG. 1

a perspective view of a housing part of a muffler assembly;

FIG. 2

a perspective view of a insertion part of the muffler assembly;

FIG. 3

a perspective view of a closing element of a muffler assembly;

FIG. 4

a view into the interior of the housing part according to FIG. 1 ;

FIG. 5

a perspective view of the muffler assembly in its assembled state and in its preferred installation situation;

FIG. 6

a section in a vertical plane through a laterally arranged in the installation situation fastener according to FIG. 5 , where the silencer assembly opposite FIG. 5 is shown rotated by 90 ° down;

FIG. 7

a section through the muffler assembly according to FIG. 5 in a vertical plane, through the center of the muffler assembly;

FIG. 8

a first absorption element;

FIG. 9

a view into the interior of the housing part starting from a running in a vertical plane section transverse to the axial extent of the muffler assembly in the assembled state, wherein the section in the region of a second segment-like cutout of the first absorption element according to FIG. 8 is laid;

FIG. 10

a view into the interior of the insertion part in the range of two slices of the insertion part, by means of a running in a vertical plane section according to FIG. 6 transverse to the axial extent of the muffler assembly in the assembled state;

FIG. 11

a second absorption element;

FIG. 12

a silencer assembly in the assembled state as a prototype (without end element) in a perspective exterior view analogous to FIG. 5 ;

FIG. 13

a section running in a vertical plane above the first absorption element through the prototype, transverse to the axial extent of the designed as a prototype muffler assembly according to FIG. 12 but with a silencer assembly turned down by about 90 °; and

FIG. 14

a view into the interior of the housing part starting from a running in a vertical plane section, transverse to the axial extent of the prototype formed muffler assembly in the assembled state (without closing element) according to FIGS. 12 and 13 , wherein the section is placed in the region of the second segment-like cutout of the first absorption element.

FIG. 1 shows a perspective view of a housing part 10 of a muffler assembly 100, in particular an assembly of a Ansauggeräuschdämpfers for a heater, in particular for a heater. The intake silencer or the silencer assembly is referred to below as the silencer 100 shortened.

It will be explained below that the muffler 100 according to the invention, in addition to the advantageous design and arrangement of the components 10, 20, 30, S1, S2 of the muffler assembly 100, achieves a broadband attenuation of sound waves L, wherein the muffler 100 in certain areas, the operating principle of Absorption or reflection as well as the combination of absorption and reflection uses.

In the foreground the FIG. 1 is a bottom of the muffler 100 visible. In the embodiment, in the later installation situation on the side (in FIG. 1 shown above) of the muffler 100, a fastener 10E arranged. The fastening element 10E is advantageously connected in one piece with the body of the housing part 10. The housing part 10 and thus the entire muffler 100 can be connected via the fastening element 10E with a body or the like. It is understood that the fastening element 10E can also be arranged at a different location of the housing part 10 of the silencer 100.

The housing part 10 has a fluid channel which comprises a first channel segment 10A, in particular an inflow channel and a second channel segment 10B angled away from the first channel segment 10A as a feed channel. In FIG. 1 Within the feed channel 10B, an axially extending projection 10B-12 is visible. In these channels 10 A, 10 B, fluid, in particular combustion air flows to the heater connected to the muffler 100.

FIG. 2 shows in a perspective view an insertion part 20 of the muffler 100. The exact arrangement of the insertion part 20 within the housing part 10 will be explained in more detail.

The insertion part 20 comprises a nozzle 20A-1 provided with a nozzle 20A, which is integrally connected to a first disc 20B-1. The first disk 20B-1 is located in the axial direction with respect to the nozzle opening 20A-1 of the nozzle 20A parallel to a second disk 20B-2 spaced from the first disk 20B-1. About the nozzle 20A, the muffler 100 is connected to the heater. The nozzle 20A is in principle on the side of the insertion part 29, an extension of the second channel segment 10B of the fluid channel.

A ridge 20G arranged in the installation situation on the underside of the insertion part 20 separates two sub-chambers 20E-1 and 20E-2 of a small resonator chamber 20E (of a second branch resonator R2) with a small volume from each other and at the same time ensures stability.

The smaller volume of the small resonator chamber 20E refers to the larger volume of a large resonator chamber 10C (a first branch resonator R1), and the branch resonators R1, R2 will be discussed in more detail.

Disposed on the second disc 20B-2 is a push-in shield 20F which extends in the assembled state inside the muffler 100 in the axial direction, the function of the push-in shield 20F being discussed in more detail below.

Between the disks 20B-1 and 20B-2, a cylindrical wall 20C is provided on the inner diameter of the disks 20B-1 and 20B-2, and in the wall 20C in the radial direction, the axially extending nozzle port 20A-1 communicating holes 20D-1 and 20D -2 are arranged, which will also be discussed in more detail later. In FIG. 2 only one of the connection openings 20D-1 is visible.

The communication ports 20D-1, 20D-2 provide access to the small, lower volume sub-chambers 20E-1 and 20E-2 of the small resonator chamber 20E as described in the description of FIG FIG. 10 will be explained in more detail.

FIG. 3 shows in a further perspective view of the lid 30 as a final element, which in the assembled state of the muffler 100 according to FIG. 5 closes the housing part 10 on one end, without the connecting opening S11 according to FIG. 7 close.

At the other end, the housing part 10 is according to FIG. 5 in the assembled state by the insertion part 20 according to FIG. 2 closed, wherein the first disc 20B-1 of the insertion part 20 is flush with the edge of the housing part 10, as in FIG. 5 is shown in a slightly perspective side view of the muffler 100.

FIG. 4 shows to further explain the construction of the housing part 10 in yet another perspective view, a view into the interior of the housing part 10th

In the FIG. 4 shown position of the housing assembly 10 corresponds to the later installation situation of the muffler 100. It is clear that the supply channel 10B below and the fastener 10E are arranged laterally. It is also clear that the large resonator chamber 10 C is arranged in the installation situation of the muffler 100 above.

The viewing direction of the viewer in the interior of the housing part 10 is according to FIG. 4 Starting from the nozzle 20A directed towards the lid 30, wherein the lid 30 in FIG. 4 not mounted yet. The housing part 10 comprises the gap-like inlet channel 10A which is open on both sides and, in the assembled state, has a first housing part opening 10A-1 at one end and an inlet opening 10A-11 (see FIG FIG. 5 ) and at the other end in the assembled state to form a communication opening S11, as will be explained, is closed by the lid 30.

The housing part 10 further comprises the circular feed channel 10B, which is also initially open on both sides, and in the assembled state on one side by means of the lid 30 (see FIG. 7 ) is closed and is open on the other side facing the nozzle 20A, since there the insertion part 20 is inserted into the housing part 10, wherein the open nozzle opening 20A-1 forms an outflow opening 10B-11 for the fluid.

In addition, the housing part 10 has a third substantially circular resonator chamber opening 10C-1, which forms the access to the large resonator chamber 10C.

The large resonator chamber 10C forms a second branch resonator R2 of a plurality of sub-chambers 10C-I, 10C-II, 10C-III, as shown in FIG FIG. 9 is clarified.

It will be in FIG. 4 Furthermore, it is clear that the large resonator chamber 10C is closed on the bottom side. The floor 10C-4 is in the assembled state, such as FIG. 5 in particular illustrated on the side of the lid 30.

It is also in FIG. 4 in conjunction with the FIGS. 1 and 6 visible that the housing part 10 circumferentially has a widening 10C-2, which extends in the axial direction and whose length corresponds to the distance between the two discs 20B-1, 20B-2 of the insertion part 20. This forms in the housing part 10 a paragraph 10C-21, which ensures that the insertion part 20 in the assembled state within the housing part 10 in the axial direction assumes a defined position, in particular in the FIGS. 6 and 7 you can see.

Furthermore, according to FIG. 4 the visible end face 10B-13 of the feed channel 10B also analogous to the expansion 10C-2 relative to the nozzle-side end face 10-1 of the housing part 10 is reset in the upper region, while it is continued in the lower region in the axial direction and the one flush end face 10A-12 to the end face 10-1 of the housing part 10 forms.

The lower part of the feed channel 10B with the end face 10A-12 and the shoulder 10C-21 with the end face 10B-13 of the feed channel 10B are designed to be flush in the assembled state, such as FIG. 6 clarified.

Inside the large resonator chamber 10C is how FIG. 4 Further, a housing part plate 10D arranged, which also extends in the assembled state of the muffler 100 in the axial direction. It can be seen that the in FIG. 4 visible end face 10D-1 of the housing partial shield 10D is reset in the axial direction by an amount relative to the end face 10B-13 of the feed channel 10B, which will be discussed in more detail. In this case, the housing part plate 10D is guided to the bottom 10C-4 of the large resonator 10C and thus already forms two sub-chambers, a third sub-chamber 10C-III and a sub-chamber 10C-II / 10C-I, which in the assembled state by the insertion plate 20F in two further individual chambers 10C-II and 10C-I is divided.

Moreover, in FIG. 4 4 that the center M1 of the axially-central axis of the circular second housing part opening 10B-1 forming the supply passage 10B is eccentrically arranged with respect to the center M2 of the axial center axis of the resonator chamber opening 10C-1 of the resonator chamber 10C.

As a result, within the circular cylindrical embodiment of the resonator chamber opening 10C-1 of the muffler 100, an arrangement of the inflow channel 10A in the lower region is possible, wherein at the same time for the large resonator chamber 10C (FIG. FIG. 4 ) and also the small resonator chamber 20E ( FIG. 10 ) above the second housing part opening 10B-1 around or around the adjoining the second housing part opening 10B-1 nozzle 20A around a large space for the branch resonators R1, R2 is available. The respective installation space is advantageously used for damping low-frequency sound waves L in the large resonator chamber 10C (first branch resonator R1) and high-frequency sound waves L in the small resonator chamber 20E (second branch resonator R2).

FIG. 5 shows the muffler 100 in a perspective view obliquely from above in the assembled state. The arrow P1 shows the flow direction of the fluid in the inflow direction, wherein the inflow passage 10A forms the inflow opening 10A-11. The arrow P2 shows the flow direction of the fluid in the outflow direction, wherein the nozzle 20A forms the outflow opening 10B-11. As already defined, the sound emission direction is opposite to the flow direction of the fluid. The heater not shown is connected to the nozzle 20A.

The propagation of the sound waves L is in the FIGS. 7 and 10 shown with dashed lines L.

The FIG. 6 shows a vertically extending in a plane section through the muffler 100 by the fastener 10E, which in FIG. 6 is arranged below. Across from FIG. 6 Thus, the muffler 100 is shown rotated by 90 ° down, so that the viewer looks at the muffler 100 from above with respect to the installation situation.

The FIG. 7 shows a running in a vertical plane section through the muffler 100 right through the center of the muffler 100. The muffler 100 in FIG. 7 has the same situation as FIG. 5 with the viewer now looking from the side of the muffler 100.

The following description is in a synopsis of FIGS. 6 and 7 ,

It is especially in FIG. 6 visible that the feed channel 10B with its front-side recessed free end of the second housing part opening 10B-1 with the end face 10B-13 with respect to the second disc 20B-2 forms a distance, which will be discussed.

It is especially in FIG. 7 Furthermore, it can be seen that the insertion plate 20F also forms a distance at the front side with its free end opposite the bottom 10C-4 of the large resonator chamber 10C (FIG. FIG. 7 ), which will be discussed later.

The feed channel 10B and the inflow channel 10A form a further resonator chamber in the manner of an angled resonator tube R.

The angled resonator tube R predominantly uses the functional principle of the absorption of sound waves L in the region of the straight feed channel 10B, since it is provided with an absorber element S1.

Since the supply channel 10B is in operative connection with the angled inflow channel 10A, it is seen in the direction of propagation of the sound waves L that the functional principle of the reflection is advantageously used as well.

The sound waves L propagate to the bend between the supply passage 10B and the inflow passage 10A and reach the U-shaped communication opening S11 between the supply passage 10B and the inflow passage 10A, and are strongly reflected on the inner wall of a lid 30, and then further into the inflow passage 10B in that they are reflected on the walls of the inflow channel 10A, 10B, whereby an attenuation of the sound waves L is achieved in an advantageous manner.

In the exemplary embodiment, the resonator tube R attenuates sound frequencies in the acoustic wave range within a high-frequency frequency band by approximately 5 kHz, which depends on the volume of the resonator tube R, its cross-section and its length and the internals arranged in the resonator tube R1, such as the arranged first absorber element S1 and the absorber material ,

As an absorber material for the first absorber element S1 in the resonator tube R, an open-celled polyurethane foam based on polyester [polyester-based PU foam] is used. The open-cell PU foam forms cell-like pores, which provide for reflection of the sound waves L in the pores for damping the sound waves L in the high-frequency frequency range by about 5 kHz around. It has been found that for the damping in the resonator tube R, a polyurethane foam based on polyester with a bulk density of about 57 kg / m ³ (+/- 5 kg / m ³ ) according to ISO 845 is particularly suitable.

Advantageously, increases the length of the resonator tube R over conventional mufflers by the selected configuration, since the resonator tube R from the inflow passage 10 A and the angled supply channel 10 B is formed, whereby the noise is reduced compared to the conventional mufflers.

First absorption element S1:

Furthermore, in the FIGS. 6 and 7 illustrated how the first absorption element S1 within the feed channel 10B, here cylindrical, is arranged in FIG. 8 is shown as a detail.

The absorption element S1 extends in its longest extent from the cover 30 to the first disc 20B-2 of the insertion part 20 and is thereby easily positionable in the axial direction within the muffler 100.

The absorption element S1 is advantageously prior to installation a lying in a plane mat predeterminable thickness of about 5-10 mm, in particular 6 mm, which is rolled up for installation to the cylindrical member, so that the axially extending end faces to each other lie. A contact zone S13 forms (FIG. FIGS. 6 ) extending at the axially extending projection 10B-12 (FIG. FIGS. 1 and 6 ), so that the absorbing member S1 is uniquely positioned in the feeding channel 10B and secured against twisting at the same time. This solution is in FIG. 9 also recognizable.

The absorption element S1 according to FIG. 8 has at each end a segment-like cutout S11, S12, wherein seen in the flow direction of the fluid, the first segment-like cutout S11 forms the fluid and sound transmitting connection opening S11 between the inflow passage 10A and the feed channel 10B, as in FIG. 7 is clearly visible.

The second segment-like cutout S12 forms a radially outgoing sound-transmitting connection opening S12 between the inflow channel 10A and the large resonator chamber 10C. About this connection opening S12 takes place almost no fluid exchange, that is, the fluid does not flow into the large resonator 10C.

Second absorption element S2:

In the different sections of the FIGS. 6 and 7 a further absorption element S2 is visible, which is arranged between the discs 20B-1 and 20B-2. The exact arrangement is in the FIGS. 10 and 11 shown and will be explained in more detail in the description of the figures.

FIG. 9 first shows for further explanation a running in a vertical plane section transverse to the axial extent of the muffler 100, wherein the section in the region of second segment-like cutout S12 of the first absorption element S1 analogous to FIG. 4 is laid.

FIG. 9 and FIG. 4 differ in that in FIG. 9 in contrast to FIG. 4 the insertion part 20 is already inserted into the housing part 10 and the first absorption element S1 is already inserted.

On average, the FIG. 9 As a result, the sectional area of the insertion panel 20F in the area of the segment-like cutout S12 and the sectional area of the absorption element S1 are visible.

The insertion plate 20F is inserted with its extending in the axial direction outer end edge in a groove 10C-3, which also in FIG. 7 at least partially visible.

Through the groove 10C-3, the insertion part 20 is advantageously positioned clearly within the large resonator chamber 10C and at the same time seals against the wall of the resonator chamber 10C.

In addition, the insertion part 20 is secured against rotation within the resonator 10C. By the in FIG. 9 shown section is that through the insertion plate 20F of the insertion part 20 within the resonator chamber 10C, three sub-chambers 10C-I; Form 10C-II and 10C-III. It has been found by experiments that it is advantageous that the cross sections of the chambers 10C-I; I0C-II and I0C-III are formed substantially equal in size to effect an efficient sound attenuation.

According to the previous description, the fluid flows in FIG. 9 in the direction of the viewer, while the sound or the sound wave propagates into the feed channel 10B, that is to say into the sheet plane, and radially into the large resonator chamber 10C via the segment-like cutout S12. The resonator chamber 10C with the three large chambers 10C-I; 10C-II and 10C-III forms a resonator tube R of three adjacent large chambers 10C-I; 10C-II and 10C-III, which are interconnected by two connection openings A1, A2.

The first connection opening A1 ( FIG. 7 ) is formed by the gap between the bottom 10C-4 of the large resonator chamber 10C and the free end of the insertion shield 20F.

The second connection opening A2 is located between the end face 10D-1 of the housing partial shield 10D inside the resonator chamber 10C and that of the resonator chamber 10C Wall of the second disc 20B-2 of the insertion plate 20F formed. It has been found that it is advantageous if the cross sections of the connection openings A1, A2 are of substantially equal size, as in the exemplary embodiment shown, in order to bring about efficient sound damping.

In addition, it has been found by experiments that it is advantageous if the cross sections of the connection openings A1, A2 are substantially the cross sections of the chambers 10C-I; 10C-II and 10C-III correspond to a highly effective sound dissipation within the interconnected chambers 10C-I; To reach 10C-II and 10C-III.

The sound wave spreads according to a synopsis of FIGS. 7 and 9 from the nozzle opening 20A-1 of the nozzle 20A from the segment-like opening S12 of the first absorption element in the radial direction branching off through the connection opening S12 into the first chamber 10C-I of the resonator tube R branches off again in the axial direction and passes through the first chamber 10C-I ( FIG. 9 into the leaf plane), after which it deflects through the first connection opening A1 and enters the second chamber 10C-II at the bottom 10C-4 in a reflective manner ( FIG. 9 from the leaf level) and once again deflected via the second connection opening A2 into the third chamber 10C-III (FIG. FIG. 9 into the leaf level). It is understood that the sound waves L also from the walls of the chambers 10C-I; 10C-II and 10C-III are reflected and damped.

It has been ensured that by the described resonator chamber 10C with the three sub-chambers 10C-I; 10C-II and 10C-III sound waves L are attenuated in a low-frequency frequency band in the range of about 200 Hz to 500 Hz. Thus, in the resonator chamber 10C, low-frequency intake noise, which is known near the intake opening of the heater, as is known, in particular, from a rumbling combustion noise, is effectively damped.

The optimal overall length of the resonator tube R was determined by special experiments using a prototype. In addition, the opening size of the connection opening S12 of the segment-like section of the first absorption element S1 was also determined by special experiments by means of the prototype, as will be explained.

FIG. 10 shows for further explanation of the muffler 100 extending in a vertical plane section transverse to the axial extent of the muffler 100, wherein the section is in the region between the two discs 20B-1 and 20B-2 of the insertion part 20.

In this illustration according to FIG. 10 For example, the communication holes 20D-1 and 20D-2 are visible to the sub-chambers 20E-1 and 20E-2 of the small resonator chamber 20E.

These sub-chambers 20E-1 and 20E-2 of the resonator chamber 20E form a second branch resonator R2 radially branching from the feed channel 10B. The second branch resonator R2 is designed such that it uses the principle of operation of the combination of absorption and reflection.

The two sub-chambers 20E-1 and 20E-2 of the small resonator chamber 20E are separated from each other by an upper vertical divider 20H. Thus, between the two disks 20B-1 and 20B-2, another resonator space is formed in the manner of a small resonator chamber 20E with a smaller volume.

The upper vertical divider 20H is starting from the center M1 of the feed channel 10B in FIG FIG. 10 formed in the vertical direction only so long that it does not reach the inner wall of the expansion 10C-2 of the resonator chamber opening 10C-1, so that the two sub-chambers 20E-1 and 20E-2 are still connected to each other in the upper area.

Thereby, on the divider 20H via a slot S23 according to FIG FIG. 11 in the upper region of the sub-chambers 20E-1 and 20E-2, the second absorbent member S2 between the two discs 20B-1 and 20B-2 are easily positioned, with the divider 20H engaging in the slot S23.

The second absorption element S2 forms two wing-like elements S21 and S22 corresponding to the inner contour of the sub-chambers 20E1 and 20E-2, so that the elements S21 and S22 in the two sub-chambers 20E-1 and 20E-2 can be arranged accurately. The second absorption element S2, viewed in the axial direction, has a thickness of approximately 5-10 mm, in particular 5 mm.

The small resonator chamber 20E thus forms, viewed in the propagation direction of the sound waves L, first a resonator chamber without absorption element S2 and then a resonator chamber with the absorption element S2, wherein the small resonator chamber 20E is formed from the two interconnected subcompartments 20E-1 and 20E-2.

The embodiment described and the absorbent internals in the small resonator chamber 20E ensure that the functional principle of the combination of reflection and absorption is utilized by the two chambers 20E-1 and 20E-2 first by reflection and then by the absorber element S2 by absorption becomes.

As already explained, the small resonator chamber 20E is formed relatively large by the eccentric design of the muffler 100 compared to other mufflers from the prior art, so that the damping effect compared to conventional mufflers is further improved. The center point M1 of the axial center axis of the second housing part opening 10B-1 which constitutes the supply passage 10B is positioned as shown in FIG FIG. 10 with respect to the center M2 of the axial center axis of the small resonator chamber 20E eccentrically.

The sound waves L propagate in the small resonator chamber 20E according to FIG FIG. 10 via the connection openings 20D-1 and 20D-2 respectively in the radial direction, wherein it has been found that the segment-like connection openings 20D-1, 20D-2 are advantageously in an angular range between 60 ° to 150 ° and in particular in each case approximately 120 ° be to effect an efficient attenuation of the sound waves L.

In the exemplary embodiment, the small resonator chamber 20E designed as branch resonator R2 likewise dampens sound frequencies in the acoustic wave range within a high-frequency frequency band by approximately 5 kHz, that of the volume of the small resonator chamber 20E, its chamber cross-section, the cross-sections of the connection openings 20D-1, 20D-2 as well as those in FIG Branch resonator R2 arranged internals, such as the arranged second absorber element S2 and the absorber material depends.

As the absorber material for the second absorber element S2 in the resonator chamber 20E, an open-celled polyurethane-based polyurethane foam [polyester-based polyurethane foam] is also used. The open-cell PU foam of the second absorber element S2 likewise forms cell-like pores, which provide for reflection of the sound waves L in the pores for damping the sound waves L in the high-frequency frequency range by approximately 5 kHz. It has been found that for cushioning in the resonator chamber 20E, a polyester-based polyurethane foam having a bulk density of about 120 kg / m ³ (+/- 12 kg / m ³ ) according to ISO 845 is particularly suitable.

It becomes clear that both in the resonator tube R and in the second branch resonator R2 sound waves L in the high-frequency frequency range are attenuated by approximately 5 kHz, but different foams are used. It has been found according to the invention that the other different boundary conditions, such as respectively different volumes, different cross sections of the resonator chambers and respectively different cross sections of the connection openings, different foams conditionalize the desired high-frequency frequency ranges by about 5 kHz in the manner described.

As mentioned, both in the resonator tube R and in the second branch resonator R2, sound waves L in the higher-frequency range are attenuated by approximately 5 kHz. As a result, high-frequency intake noise, which is known in particular by a turbine-like noise of an intake fan of the heater, is effectively damped in the small resonator chamber 20E near and through the second branch resonator R2 away from the port side intake port of the heater.

The FIGS. 12 to 14 The prototype P100 differs from the series type 100 on the one hand in that in the third chamber 10C-III a displaceable in the axial direction volume controller 10V is arranged, which consists of the housing part 10 is pulled out so that it is displaceable on both sides in the axial direction. By means of the volume regulator 10V, the optimum overall length of the large resonator chamber 10C was determined in order to bring about a highly efficient damping of the sound waves L.

In FIG. 12 is illustrated by the arrow P4, as the volume regulator 10V is reciprocated in corresponding experiments within the third chamber 10C-III, at predetermined cross sections of the chambers 10C-I, 10C-II and 10C-III and at predetermined cross sections of the overflow or connecting openings A1, A2 determine the optimum length of the large resonator chamber 10C formed from the sub-chambers 10C-1, 10C-II and 10C-III with the most efficient attenuation of the sound waves L.

Analogously, as a further difference between the prototype P100 and the series type 100, the first absorption element S1 has likewise been pulled out of the housing part 10, so that by rotation in accordance with the arrow P3 in FIG FIG. 14 it is possible to rotate the segment-like opening S12 of the first absorption element S1 with respect to the first chamber 10C-I of the large resonator chamber 10C.

The necessary open cross-section of the segment-like cutouts S11 and S12 of the first absorption element S1 could thus be determined by corresponding experiments, in which a highly efficient attenuation of the sound waves entering the large resonator chamber 10C and deflected and reflected between the feed channel 10B and the inflow channel 10A through the connection opening L is feasible. As a result, the opening angles of the segment-like cutouts S11 and S12 and also the width of the cutouts S11, S12 necessary in the axial direction were determined.

It is thus inventively contemplated that, depending on the frequencies occurring, leading to the unwanted Ansauggeräuschen, within the Ansauggeräuschdämpfers 100 a controlled system is realized, depending on the detected sound frequencies on the displaceable in the axial direction volume controller 10V or via the rotatable first absorption element S1 an adaptation of the frequencies to be damped within corresponding frequency bands and thus a further optimized sound attenuation takes place.

By the volume regulator 10V, the length of the resonator 20E and the first absorption element S1, the size of the connection opening S12 to the large resonator 10C is variable and adjustable within the planned controlled system. Volumetric regulator 10V and rotatable first absorption element S1 are no longer prototype components in such an embodiment, but instead represent series components.

The described solution according to the invention also has the advantage that the body of the muffler is formed only of three simple components, the housing part 10, the insertion part 20 and the lid 30. By the described insertion of the insertion part 20 in the housing part 10 and placing the lid 30 can be assembled without error by simple installation of the body of the muffler 100 from the worker. The positioning of the housing part relative to the insertion part 20 via the already explained groove 10C-3 on the inner wall of the large resonator 10C. The lid 30 also has appropriate provisions for error-free installation.

The complementation with the absorption elements S1 and S2 is likewise simple, wherein the absorber elements S1 and S2 can be easily and securely positioned by the operator before assembly of the body into the feed channel 10B or into the small resonator chamber 20E.

Thus, with the absorption elements S1 and S2, only a five-part intake silencer is available which, by assembly, forms a large resonator chamber 10C with three sub-chambers 10C-1, 10C-II, 10C-III (branch resonator R1) and a small resonator chamber 20E with two sub-chambers 20E- 1 and 20E-2 (branch resonator R2 is formed.

The angled resonator tube R is already applied in the housing part 10.

The material requirement is small and the space required for reducing the intake noise in the resonator chambers 10C, 20E is particularly large compared to conventional silencers, as the explained eccentric design has been selected.

A complicated nesting of the resonator cavities, which is known from the prior art, is overcome by the inventive solution, whereby the components are simple to produce as individual components and require less material, which also causes a low weight and lower costs.

It has been determined in experiments that the externally recordable noise level is reduced by up to 15 dB compared to conventional silencers.

Another advantage is that an efficient reduction of the noise effect of intake noise is also achieved by the first absorption element S1 in the feed channel 10B, since it has been found that the deflection of the inflow channel 10A into the feed channel 10B also has a reducing and damping effect Sound is effected.

In addition, the inlet channel 10A, which is arranged in the installation situation of the muffler 100 on the underside, acts as a collecting space for condensate possibly occurring within the muffler 100.

It is envisaged to arrange the muffler 100 inclined in the installation situation with respect to an imaginary horizontal, so that accumulating condensate during operation of the heater and the muffler 100 and also outside the operation by the corresponding slope via the inlet opening 10A-11 of the fluid exits.

LIST OF REFERENCE NUMBERS

100

Silencer assembly (series type)

P100

Muffler assembly (prototype)

10

housing part

10-1

face

10A

first channel segment / inflow channel

10A-1

first housing part opening

10A-11

inflow

10A-12

face

10B

second channel segment / feed channel

10B-1

second housing part opening

10B-11

outflow

10B-12

head Start

10B-13

face

M1

Center of the second channel segment 10B

10C

large resonator chamber

10C-1

Resonatorkammeröffnung

10C-2

widening

10C-21

paragraph

10C-3

groove

10C-4

ground

10C-I

first compartment

10C-II

second sub-chamber

10C-III

third compartment

M2

Center of the large resonator chamber opening 10C

10D

Housing part shield

10D-1

face

10E

fastener

10V

volume control

20

insertion part

20A-1

nozzle opening

20A

Support

20B-1

first disc

20B-2

second disc

20C

wall

20D-1

Connection opening as a segmental cutout in Fig. 20C

20D-2

Connection opening as a segmental cutout in Fig. 20C

20E-1

member chamber

20E-2

member chamber

20E

small resonator chamber

20G

web

20H

divider

20F

slide plate

30

cover

A1

first connection opening

A2

second connection opening

P1

Flow direction of the fluid in the inflow direction

P2

Flow direction of the fluid in the outflow direction

P3

Direction of rotation of absorption element s S1

P4

Displacement movement of the volume controller 10V

R

resonator

R1

Abzweigresonator

R2

Abzweigresonator

S1

first absorption element

S2

second absorption element

S11

Connection opening as segment-like section of S1

S12

Connection opening segment-like cutout S1

S13

contact zone

S21

wing-like element

S22

wing-like element

S23

slot

L

sound waves

Claims (8)

1. Silencer assembly (100) containing an insertion part (20) which is fitted into a housing part (10) in an assembled state of the silencer assembly (100), wherein the housing part (10) has a fluid duct in which a fluid flows in an axial direction of the silencer assembly (100), from an inflow opening (10A-11) to an outflow opening (10B-11), and which functions simultaneously as a resonator tube (R) for sound waves (L) which propagate in the fluid duct, characterized in that the fluid duct comprises a first duct segment (10A) which is open on both sides, as an inflow duct with the inflow opening (10A-11) for the fluid, and a second duct segment (10B) which is open on both sides and is located coaxially with respect to the first duct segment (10A) as a feed duct with the outflow opening (10B-11) for the fluid, such that the inflow opening (10A-11) and the outflow opening (10B-11) are arranged on one side of the silencer assembly (100), since the fluid duct is deflected within the housing part (10) by means of a U-shaped connecting opening (S11) on a side opposite the insertion part (20), wherein in the assembled state a closure element (30) closes off the housing part (10) on one end side without in the process closing off the U-shaped connecting opening (S11), wherein before the assembled state the housing part (10) and the insertion part (20) each have an open resonator chamber (10C, 20E) for, in each case, one branching resonator (R1, R2) which branches off from the fluid duct, said branching resonators (R1, R2) being closed in the assembled state by insertion of the insertion part (20) into the housing part (10) and being operatively connected in a sound-transmitting fashion to the fluid duct which functions as a resonator tube (R).
2. Silencer assembly (100) according to Claim 1, characterized in that a longitudinal axis, lying at a central point (M1) in the axial direction, of a second housing opening (10B-1) which forms a feed duct (10B) of the fluid duct is arranged eccentrically with respect to a central point (M2) of the longitudinal axis of the resonator chambers (10C, 20E) of the branching resonators (R1, R2) which lies in the axial direction.
3. Silencer assembly (100) according to Claim 1, characterized in that before the assembled state the housing part (10) has the one open resonator chamber (10C) which comprises a housing sub-plate (10D) which extends in the axial direction and forms two sub-chambers in the resonator chamber (10C) .
4. Silencer assembly (100) according to Claim 1, characterized in that the insertion part (20) has an insertion plate (20F) which in the assembled state is inserted into the resonator chamber (10C) embodied as a branching resonator (R1), in a coaxial direction with respect to the housing sub-plate (10D) which extends in the axial direction, such that in the assembled state three sub-chambers (10C-I, 10C-II; 10C-III) are formed in the resonator chamber (10C) and are connected to the fluid duct via a sound-transmitting connecting opening (S12) and are for their part connected in a sound-reducing fashion via connection openings (A1, A2) according to the operational principle of reflection.
5. Silencer assembly (100) according to Claim 1, characterized in that the insertion part (20) has the other resonator chamber (20E) which is embodied as a branching resonator (R2) and is constructed, when viewed in the axial direction, from two disks (20B-1, 20B-2) which lie one behind the other and are arranged on a cylindrical wall (20C) on their internal diameter, wherein the wall (20C) forms a support opening (20A-1), extending in an axial direction of the silencer assembly (100), of the insertion part (20), wherein in the wall (20C) sound-transmitting connecting openings (20D-1, 20D-2) are constructed to form two sub-chambers (20E-1, 20E-2) which are connected to the fluid duct via the connecting openings (20D-1, 20D-2) and are for their part connected in a sound-reducing fashion according to the operational principle of reflection.
6. Silencer assembly (100) according to Claim 1, characterized in that arranged in the feed duct (10B) of the fluid duct is a first absorption element (S1) which is constructed from a first absorption material, in particular a polyurethane foam based on polyester with a bulk density of approximately 57 kg/m³ (+/- 5 kg/m³), such that the fluid duct which is embodied as a resonator tube (R) achieves a sound-reducing effect according to the operational principles of absorption and of reflection.
7. Silencer assembly (100) according to Claims 1 and 5, characterized in that, in the resonator chamber (20E) of the insertion part (20), the resonator chamber (20E) is arranged only as a partially filling, second absorption element (S2) which is constructed from a second absorption material, in particular a polyurethane foam based on polyester, with a bulk density of approximately 120 kg/m³ (+/-12 kg/m³), such that the resonator chamber (20E) which is embodied as a branching resonator (R2) achieves a sound-reducing effect according to the operational principles of absorption and of reflection.
8. Silencer assembly (100) according to Claims 1 and 3, characterized in that the resonator tube (R) and the second branch resonator (R2) damp high-frequency sound waves (L) within a high-frequency frequency band, while in the first branch resonator (R1) low-frequency sound waves (L) within a low-frequency frequency band are damped.

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