Silencer

• US 20030173146A1
• Filed: 02/13/2003
• Published: 09/18/2003
• Est. Priority Date: 06/13/2001
• Status: Active Grant

• Current Assignee: Woco Industrietechnik GmbH (WOCO GmbH & Company KG)
• Original Assignee: WOCO Franz-Josef Wolf & Company GmbH
• Inventors: Gartner, Udo, Hohmann, Josef, Wolf, Anton, Wolf, Franz Josef
• Granted Patent: US 6,802,388 B2
• Time in Patent Office: Days
• US Class Current: 181/224
• CPC Class Codes: F01N 1/02 by using resonance
• CPC Class Codes: F01N 1/06 by using interference effect
• CPC Class Codes: F02M 35/1211 by using inserts in the air intake flow path, e.g. baffles, throttles or orifices; Flow guides F02M35/1244 takes precedence
• CPC Class Codes: F02M 35/1216 by using a plurality of holes, slits, protrusions, perforations, ribs or the like; Surface structures; Turbulence generators
• CPC Class Codes: F02M 35/1227 by using multiple air intake flow paths, e.g. bypass, honeycomb or pipes opening into an expansion chamber
• CPC Class Codes: F02M 35/1266 comprising multiple chambers or compartments

Abstract

The invention relates to a silencer (1) for noise-laden gas pipes, especially for a suction pipe and/or an exhaust pipe of an internal combustion engine, comprising an outer pipe (2) with an inlet side (3) and an outlet side (4), a plurality of diaphragm rings (9, 9′, 9″, 9′″,9″″) each with an outer surface connected (5) to the inner surface of the outer pipe (2),at least one insert (6) with an outer surface connected (7) to the inner surface of the outer pipe (2) and/or the diaphragm rings (9, 9′, 9″, 9′″, 9″″) and with a plurality of openings (8) which are closed on one side. Said insert (6) forms sub-pipes for the gas flow in the silencer, and the openings (8), which are closed on one side, open into the sub-pipes, the depth thereof being /4 in relation to the wavelength of a frequency to be silenced. At least one perforated wall (10, 10′, 11, 11′), extends between at least two diaphragm rings (9, 9′, 9″, 9′″, 9″″) whereby an outer surface is connected (7) to at least one inner surface of the two diaphragm rings (9, 9′, 9″, 9′″, 9″″), wherein at least one resonance cell is fixed between the two diaphragm rings (9, 9′, 9″, 9′″, 9″″) of the perforated wall (10, 10′, 11, 11′) and the outer pipe (2).

Claims

1. Noise damper (1) for pipelines carrying noise-laden gasses, particularly for an intake line and/or exhaust gas line of an internal combustion motor, comprising

an outside pipe (2) with an admission side (3) and a discharge side (4),

a plurality of diaphragm rings (9, 9′

, 9″

, 9′

″

,9″

″

) having a respective outside surface in communication (5) with the inside surface of the outside pipe (2)

and at least one insert (6) having an outside surface in communication (7) with the inside surface of the outside pipe (2) and/or of the diaphragm rings (9, 9′

, 9″

, 9′

″

, 9″

″

) and having a plurality of openings (8) closed at one side, whereby the insert (6) forms sub-lines for the gas flow in the noise damper (1), and the openings (8) closed at one side open into the sub-lines and comprise a depth of λ

/4 with reference to the wavelength λ

of a frequency to be damped, characterized by

by at least one apertured wall (10, 10′

, 11, 11′

) that extends between at least two diaphragm rings (9, 9′

, 9″

, 9′

″

, 9″

″

) with an outside surface in communication (7) with at least the inside surface of the two diaphragm rings (9, 9′

, 9″

, 9″

′

, 9″

″

), whereby at least one resonance chamber is defined between the two diaphragm rings (9, 9′

, 9″

, 9′

″

, 9″

″

), the apertured wall (10, 10′

, 11, 11′

) and the outside pipe (2).

2. Noise damper according to claim 1, characterized in that the insert (6) comprises essentially plate-shaped inside walls that are provided at both sides with the openings (8) closed at one side, that are arranged essentially cross-shaped or star-shaped in radial crossection and that preferably extend over essentially the entire axial length of the outside pipe (2).

3. Noise damper according to claim 2, characterized in that the openings (8) closed at one side are arranged offset relative to one another at both sides of an inside wall.

4. Noise damper according to one of the preceding claims, characterized in that the openings (8) closed at one side are arranged essentially in rows from the admission side (3) to the discharge side (4), whereby the depth of the openings (8) closed at one side are [sic] the same within a row and different from row to row, preferably with increasing depth from the admission side (2) [sic] to the discharge side (4).

5. Noise damper according to one of the preceding claims, characterized in that the distance between the diaphragm rings (9, 9′

, 9″

, 9′

″

, 9″

″

) differs, preferably increasing from the admission side (3) to the discharge side (4).

6. Noise damper according to one of the preceding claims, characterized in that at least one resonance chamber and at least one hole (13, 13′

) in the apertured wall (11, 11′

) of the resonance chamber form a Helmholtz resonator that can be tuned to a frequency band to be damped via the volume of the resonance chamber, the crossectional area of the hole (13, 13′

) in the apertured wall (11, 11′

) of the resonance chamber and the wall thickness of the apertured wall (11, 11′

) of the resonance chamber in the region of the hole (13, 13′

).

7. Noise damper according to claim 6, characterized in that the wall thickness of the apertured wall (11, 11′

) amounts to 0.6 through 5 mm, preferably 1 through 3 mm.

8. Noise damper according to one of the preceding claims, characterized in that one or more apertured walls (10, 10′

, 11, 11′

) arranged following one another from the admission side to the discharge side extends or, respectively, extend over the entire axial length of the outside pipe (2), preferably concentrically within the outside pipe (2).

9. Noise damper according to claim 7 or 8, characterized in that a plurality of resonance chambers are provided, whereby frequency bands to be damped by neighboring resonance chambers preferably at least partially overlap and/or the resonance chambers form reflection sound dampers and/or absorption sound dampers.

10. Noise damper according to one of the preceding claims, characterized in that the diaphragm rings (9, 9′

, 9″

, 9′

″

, 9″

″

) are provided with openings closed at one side that open into the sub-lines and also comprise a depth of λ

/4, whereby the depth preferably increases from the admission side (3) to the discharge side (4).

11. Noise damper according to one of the preceding claims, characterized in that the outside pipe (2) , the diaphragm rings (9, 9′

, 9″

, 9′

″

, 9″

″

), the insert (6) and/or the apertured wall or, respectively, the apertured walls (10, 10′

, 11, 11′

) is or, respectively, are fashioned of a metal, particularly aluminum, a heat-resistant plastic, particularly a fiber-reinforced plastic, hard rubber and/or a ceramic, such as a porous sintered material.

12. Noise damper according to one of the preceding claims, characterized in that the outside pipe (2), the diaphragm rings (9, 9′

, 9″

, 9′

″

, 9″

″

), the apertured wall (10, 10′

, 11, 11′

) and/or the insert (6) are integrally formed, preferably as an aluminum diecasting.

13. Noise damper according to one of the preceding claims, characterized in that the outside pipe (2), the insert (6), the openings (8) closed at one side in the insert (6) and/or the holes (12, 12′

, 13, 13′

) in the apertured wall (10, 10′

, 11, 11′

) is or, respectively, are essentially rotationally symmetrical, preferably circular, in radial section.