SOUND REDUCER, METHOD OF MAKING SAME, AND FLUID CONDUIT SYSTEM INCLUDING SUCH A SOUND REDUCER

Abstract

A sound reducer (10) has a housing (14) with a housing wall bounding an interior space (141). The housing wall has a mantle (142) extending longitudinally along a housing axis. Two end walls (143) are transverse to the housing axis. A main tube (12) extends through the interior space (141) and has a first and second ends (121). Windows (22) are formed as tube wall openings within the interior space (141). The first end (121) of the main tube (12) is fixed at a first passage (18a) through the housing wall, and the second end (122) of the main tube (12) is fixed at a second passage (18b) through the housing wall. At least the second passage (18b) passes eccentrically through one of the end walls (143). The main tube (12) is curved in a main plane and the first passage (18a) passes through the mantle (142).

Claims

1. A sound reducer (10), comprising: a housing (14) with an interior space (141) and a housing wall bounding the interior space (141), the housing wall comprising a mantle (142) extending longitudinally along a housing axis with a mantle inner surface rotationally symmetrical about the housing axis and two end walls (143) aligned transverse to the housing axis, each of the end walls defining an associated end wall inner surface, and a main tube (12) extending through the interior space (141) and having a first end (121), a second end (121), and windows (22) formed as tube wall openings within the interior space (141) and, the first end (121) of the main tube (12) being fixed in or at a first passage (18a) passing through the housing wall and the second end (122) of the main tube (12) being fixed in or at a second passage (18b) passing through the housing wall, with at least the second passage (18b) passing eccentrically through one of the end walls (143), wherein the main tube (12) is curved in a main plane and the first passage (18a) passes through the mantle (142).

2. The sound reducer (10) of claim 1, wherein the housing axis lies in the main plane of the main tube (12) and the centers of the passages (18a, 18b) lie on different sides of the housing axis.

3. The sound reducer (10) of claim 1, wherein axial directions of the first and second ends (121, 122) of the main tube (12) are perpendicular to each other.

4. The sound reducer (10) of claim 3, further comprising windows (22) arranged on radially outer and radially inner apex lines of the main tube (12), in each case in relation to the curvature of the main tube (12), and adjacent to the passages (18a, 18b) and offset from one another in such a way that in each orientation of the sound reducer (10) with vertical alignment of one of its main tube ends (121, 122) one of the windows (22) is positioned at a lowest point of the main tube (12) within the interior space (141).

5. The sound reducer (10) of claim 1, wherein the ends (121, 122) of the main tube (12) engage positively in the passages (18a, 18b).

6. The sound reducer (10) of claim 5, wherein the ends (121, 122) of the main tube (12) project through the passages (18a, 18b).

7. The sound reducer (10) of claim 1, wherein the main tube (12) is fit positively into a contour of the interior space (141) so that edges of the first and second ends (121, 122) lie flush against the edges of the passages (18a, 18b).

8. The sound reducer (10) of claim 7, wherein the edges of the first and second ends (121, 122) of the main tube (12) are corrugated for form-fit adaptation to curvatures of the inner surfaces of the mantle and end walls (142, 143).

9. The sound reducer (10) of claim 8, wherein areas of the main tube (12) between the first and second ends (121, 122) pass through the interior space (141) otherwise without contact.

10. The sound reducer (10) of claim 1, wherein housing (14) consists of first and second interconnected axial half-shells (14a, 14b), the first axial half shell (14a) carrying the first passage (18a) and the second axial half shell (14b) carrying the second passage (18b).

11. The sound reducer (10) of claim 10, wherein the first and second half-shells (14a, 14b) are identically shaped except for the position of their passages (18a, 18b).

12. The sound reducer (10) of claim 11, wherein the first and second half-shells (14a, 14b) have local wall thickenings (20) in regions of the mantle of the first half-shell (14a) having the first passage (18a) and in regions of the end wall of the second half-shell (14b) having the second passage (18b), the respective passage (18a, 18b) passing through the wall thickenings.

13. A fluid conduit system comprising the sound reducer (10) of claim 1 through which a gaseous fluid can flow, and connecting tubes (24) fluid-tightly connected to the ends of the main tube (12) of the sound reducer (10).

14. The fluid conduit system of claim 13, wherein the connecting tubes (24) are inserted into the ends (121, 122) of the main tube (12).

15. The fluid conduit system of claim 13, wherein the connecting tubes (24) are butt welded to the ends (121, 122) of the main tube (12).

16. The fluid conduit system of claim 13, wherein the connecting tubes (24) are plugged onto the ends (121, 122) of the main tube (12).

17. The fluid conduit system of claim 13, designed as a refrigerant circuit of a motor vehicle air conditioning system.

18. A method of manufacturing a sound reducer (10) comprising: providing first and second housing half-shells (14a, 14b), each comprising a mantle (142) extending longitudinally along a shell axis with a mantle inner surface rotationally symmetrical about the shell axis and an end wall (143) oriented transversely to the shell axis with an associated end wall inner surface; providing a main tube (12) curved in a main plane and having first and second ends (121, 122); making a first passage (18a) in an edge region near the end wall of the mantle (142) of the first half-shell (14a) and making a second passage (18b) off-center in the end wall (143) of the second half-shells (14b); pre-fixing the first end (121) of the main tube (12) at the first passage (12); placing the second half-shell (14b) on the first half-shell (14a) so that their mantle edges abut one another, the shell axes lie coaxially with respect to one another in the main plane of the main tube (12), and the second end (122) of the main tube (12) is pre-fixed in or at the second passage (18b), the main tube (12) being pre-fixed in a form-fitting manner in the interior space (141), material bonding of the mantle edges to each other to form the housing (14).

19. The method of claim 18, wherein the pre-fixing the first end (121) of the main tube (12) at the first passage (18a) comprises positively inserting a mounting aid mandrel into the first passage (18a) and the first end (121) of the main tube (12).

20. The method of claim 18, wherein the ends (121, 122) of the main tube (12) prefixed at the passages (18a, 18b) are connected to the housing (14) by a material bond.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is perspective view of a sound reducer according to an embodiment of the invention.

[0026] FIG. 2 is a top view of the sound reducer of FIG. 1.

[0027] FIG. 3 is a cross-section taken along line III-III in FIG. 2.

[0028] FIGS. 4A-4D are cross-sections through an alternative embodiment of a sound reducer according to the invention in four orientations.

[0029] FIG. 5 is a detailed view of the connection point of a sound reducer according to the invention with the connection tube attached,

[0030] FIG. 6 is a detailed representation of the connection point of a sound reducer according to the invention with a butt-welded connection tube,

[0031] FIG. 7 is a detailed view of the connection point of a sound reducer according to the invention with the connection tube inserted,

[0032] FIG. 8 is a detailed view of the connection point of a sound reducer according to the invention with the connection tube inserted,

[0033] FIG. 9 is a section through a further embodiment of a sound reducer according to the invention.

[0034] FIG. 10 is a perspective view of one end of the main tube of the sound reducer of FIG. 9.

DETAILED DESCRIPTION

[0035] Identical reference signs in the figures indicate identical or analogous elements.

[0036] FIGS. 1 to 3 show an embodiment of a sound reducer 10 according to the invention in different representations, namely in perspective in FIG. 1, in plan view in FIG. 2, and in section along the section line III-III of FIG. 2 in FIG. 3. These figures will first be discussed together.

[0037] The sound reducer 10 comprises a main tube 12 that is curved at an angle of 90° so that its two ends, namely its first end 121 and its second end 122, are at right angles to each other. The curvature in the central region 123 of the main tube 12 defines a main plane along which the section in FIG. 3 is guided.

[0038] The main tube 12 is enclosed by a housing 14 that, in the illustrated embodiment consists of essentially identical first and second half-shells 14a and 14b. The half-shells 14a, 14b are placed on each other with their mantle edges and are welded together along this connecting line 16. The resulting housing 14 thus encloses an interior space 141 bounded by a substantially cylindrical mantle 142 and two end walls 143 oriented substantially perpendicular to the cylinder axis or housing axis and having concavely curved inner end wall surfaces.

[0039] Each of the two half-shells 14a, 14b has a passage 18a, 18b. The first passage 18a arranged in the first half-shell 14a is positioned in the housing mantle 142, while the second passage 18b arranged in the second half-shell 14b is positioned in the end wall 143 belonging to the second half-shell 14b. Both passages 18a, 18b are positioned in their respective associated housing wall in close proximity to the respectively other type of housing wall. This means that the first passage 18a, which is arranged in the mantle 142, is positioned close to the end wall 143 associated with the first half-shell 14a, while the second passage 18b, which is arranged in end wall 143 associated with the second half-shell 14b, is positioned close to the mantle 142. The 90° curved main tube 12 therefore passes through the inner space 141 along the longest possible path in the case of a simple curvature.

[0040] The figures clearly show wall thickenings 20 which each half-shell 14a, 14b carries in the mantle and end wall region in which one of the passages 18a, 18b is formed in at least one of the half-shells 14a, 14b. According to a particularly advantageous manufacturing process, both half-shells 18a, 18b are manufactured with the same tool, in particular a deep-drawing tool, and therefore initially are identical in shape. The passages 18a, 18b distinguishing the two half-shells 14a, 14b were introduced subsequently by machining, in particular by means of drilling.

[0041] FIG. 3 clearly shows four windows 22, via which the interior space 141 is in fluid-conducting communication with the interior of the main tube 12. In this way, a so-called Helmholtz resonator is realized with the sound reducer 10, and the interior space 141 acts as a resonance chamber.

[0042] FIGS. 1 to 3 do not show the sound reducer 10 alone; also shown are the ends of connecting tubes 24 that are inserted from the outside into the passages 18a, 18b and butt-welded to the ends 121, 122 of the main tube 12 (and thereby additionally to the housing 14, in particular to the edges of the passages 18a, 18b).

[0043] FIGS. 4a-4d show an alternative embodiment of a sound reducer 10 according to the invention, in which the ends 121, 122 of the main tube 12 project through the passages 18a, 18b. The connecting tubes 20 are fit onto the ends 121, 122 projecting beyond the housing wall and welded thereto. FIGS. 4a-4d, however, serve primarily to illustrate an arrangement of the windows 22, which is considered advantageous for all embodiments of the sound reducer 10. The windows 22 penetrate the wall of the main tube vertically and are axially elongated in its main plane. This means that they are positioned on the—with respect to the main tube curvature—radially inner and radially outer apex lines. However, they are offset from each other in the direction of extension of the main tube 12. In particular, each of the four windows 22 shown is located in the immediate vicinity of the housing wall nearest to it. It follows that, as illustrated in FIGS. 4a-4d, whenever the sound reducer 10 is aligned with a vertical leg of its main tube, one of the windows 22 (circled in bold in each of the figures) is located at the lowest point of the main tube 12 is arranged in the housing 14. Accordingly, the suction by Bernoulli effect discussed in the general description occurs even at very low levels of liquid accumulated in the interior space 141.

[0044] FIGS. 5 to 8 show various ways of connecting a connecting tube 24 to an end 122 of the main tube 12. In FIG. 5, the connecting tube 24 is butt-welded to the main tube end 122, the end of the connecting tube 24 having an enlarged diameter to avoid a diameter jump inside the connected tubes. FIG. 6 shows a butt weld of the connecting tube 24 onto the main tube end 122, but the main tube 122 protrudes from the housing 14, in contrast to the embodiment of FIGS. 1 to 3. In FIGS. 7 and 8, the connecting tube 20 is inserted into a diameter-expanded main tube end 122, the diameter expansion starting in the interior space 141 in the embodiment of FIG. 7, whereas in the embodiment of FIG. 8 it only starts outside the housing 14.

[0045] FIGS. 9 and 10 illustrate an embodiment where the ends 121, 122 of the main tube 12 do not project into or even through the passages 18a, 18b. Rather, as can be seen in particular in FIG. 10, the end ring surface of the main tube ends 121, 122 is corrugated in such a way that it nestles exactly around the associated passage 18a, 18b against the mantle and associated end wall inner surface. In this regard, there is only one exact position and orientation of the main tube 12 in which it fits within the housing 14. In this position and orientation, the main tube 12 as a whole is positively held by the two half-shells 14a, 14b.

[0046] Of course, the embodiments discussed in the specific description and shown in the figures are only illustrative examples of embodiments of the present invention. The skilled person is provided with a wide range of possible variations in light of the present disclosure. In particular, the relative dimensions of the main tube 12 and the housing 14, as well as the positioning, shaping and dimensioning of the windows 22 and the interior space 141, are open to variations and adjustments resulting in particular from the acoustic requirements in each individual case. Typically, windows in the form of round through openings (holes) or slots are used; however, polygonal or linear (straight or curved) windows can also be used in the context of the invention. With regard to the choice of material, metal is preferred, although embodiments made of plastic are also conceivable.

LIST OF REFERENCE SIGNS

[0047] 10 sound reducer [0048] 12 main tube [0049] 121 first end of 12 [0050] 122 second end of 12 [0051] 123 central area of 12 [0052] 14 housing [0053] 14a first half-shell of 14 [0054] 14a second half-shell of 14 [0055] 141 interior space of 14 [0056] 142 mantle of 14 [0057] 143 end wall of 14 [0058] 16 connection line [0059] 18a first passage [0060] 18b second passage [0061] 20 wall thickening [0062] 22 windows [0063] 24 connection tube