SOUND REDUCER AND METHOD OF MAKING SAME

Abstract

A sound reducer (10) includes a housing (12) having a jacket (122) extending longitudinally along and rotationally symmetrical about a housing axis. Two end walls (123) are aligned transverse to the housing axis main pipe (18) and penetrating the housing (12) parallel offset to the housing axis with windows (182) formed as pipe wall openings. The main pipe (20) is sealingly fixed in passages penetrating the end walls (123). The end walls (123) have a convex base curvature that is rotationally symmetrical with the housing axis and, in the region of the passages, merge into outwardly pointing pipe sockets (16) that project in one piece and in one material from the respective end wall (123). Annular transition regions (14) are curved concavely in deviation from the convex base curvature with a radius that is at least 1/15 of the radius of the convex curvature of the base curvature.

Claims

1. A sound reducer (10), comprising: a housing (12) having a jacket (122) extending longitudinally along and rotationally symmetrical about a housing axis and further having two end walls (123) aligned transversely to the housing axis, and a main pipe (18) penetrating the housing (12) parallel offset to the housing axis with windows (182) formed as pipe wall openings, the main pipe (20) being sealingly fixed in passages penetrating the end walls (123), wherein the end walls (123) have a convex base curvature that is rotationally symmetrical with respect to the housing axis and, in a region of the passages, merge into outwardly pointing pipe sockets (16) that project in one piece and in one material from the respective end wall (123), respective annular transition region (14) between the pipe sockets (16) and the end walls (123) being curved concavely in deviation from the convex base curvature with a radius that is at least 1/15 of a radius of the convex curvature of the base curvature.

2. The sound reducer (10) of claim 1, wherein the main pipe (18) is fixed in a clamping manner in the pipe socket (16).

3. The sound reducer (10) of claim 1, wherein the main pipe (18) is welded to the pipe sockets (16).

4. The sound reducer (10) of claim 1, wherein the pipe sockets (16) project axially outwards beyond ends (181) of the main pipe (18) and the ends (181) of the main pipe (18) projecting into the pipe sockets (16).

5. The sound reducer (10) of claim 1, further comprising at least one partition wall (20) arranged in the housing (12), the at least one partition wall (20) being penetrated by the main pipe (18), the at least one partition wall (20) being aligned perpendicularly to the housing axis, and subdividing the housing interior into axial sections of different sizes.

6. The sound reducer (10) of claim 5, wherein the partition wall is sealingly connected to at least one of an outside of the main pipe (18) and an inside of the jacket (122).

7. The sound reducer (10) of claim 5, wherein the partition wall (20) is force-fittingly connected to the main pipe (18) and is pressed onto the main pipe (18) by means of an eccentrically arranged through opening.

8. The sound reducer (10) of claim 7, wherein the main pipe (18) has, at least on one side of the partition wall (20) and axially abutting the partition wall (20), a radial projection (22) fixes the partition wall (20) on the main pipe (18) axially in a form-fitting manner.

9. The sound reducer (10) of claim 1, wherein the jacket tapers conically towards its axial ends.

10. The sound reducer (10) of claim 1, wherein the housing (12) is composed of two half shells (12a, 12b) that are connected tightly to one another along their shell edges (121a, 121b).

11. The sound reducer (10) of claim 10, wherein the half-shells (12a, 12b) are products of a deep-drawing process.

12. A method of manufacturing a sound reducer (10), comprising the steps of: providing the two half shells (12a, 12b), providing a main pipe (18) with a partition wall (20) through which the main pipe (18) passes, with the partition wall (20) being sealingly connected to an outside of a pipe wall of the main pipe (18) and aligned perpendicular to a pipe axis of the main pipe (18), clampingly inserting ends (181) of the main pipe (18) into respective pipe sockets (16) of the half shells (12a, 12b) so that shell edges (121a, 121b) of the half shells (12a, 12b) come into contact with one another, and so that an outer edge of the partition wall (20) abut against inner surface of one of the half shells (12b), and sealing the shell edges (121a, 121b) together.

13. The method claim 12, wherein: an end of the main pipe that is closer to the partition wall is inserted into the pipe socket of the associated half-shell to such an extent that the outer edge of the partition wall abuts against an inner wall of a conical region of this half-shell.

14. The method according of claim 13, wherein the inner surface of the half shell has an undercut-free stop in the abutment region.

15. The method of claim 12, wherein the partition wall (20) is first pressed onto the main pipe (18), and the main pipe (18) is provided with at least one radial projection (22) axially abutting the partition wall (20).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 is a perspective view of a sound reducer according to the invention.

[0024] FIG. 2 is a longitudinal section through the sound reducer of FIG. 1.

[0025] FIGS. 3a-3g are cross-sections through the sound reducer of FIGS. 1 and 2 taken along the sectional planes IIIa to IIIg in FIG. 2.

DETAILED DESCRIPTION

[0026] Identical reference signs in the figures indicate identical or analogous elements.

[0027] FIG. 1 is a perspective view of a sound reducer 10 according to the invention, the construction of which can be explained more clearly on the basis of the longitudinal section of FIG. 2, which shows the sound reducer 10 in its approximate final installation orientation. The sound reducer 10 comprises a housing 12 that is constructed from two half-shells 12a, 12b of identical shape in the present embodiment. The half-shells 12a, 12b abut each other with their circular shell edges 121a, b and are welded together along this seam. The half-shells 12a, 12b are formed in such a way that the housing 12 has a rotationally symmetrical jacket 122 in its axial center region. In the embodiment of FIG. 2, the jacket 122 is exactly cylindrical in shape. Laterally adjoining the jacket 122 are end walls 123 that have a convex base curvature, i.e. curved towards the exterior of the housing. This base curvature is also rotationally symmetrical.

[0028] However, the rotational symmetry of the end walls 123 is broken in an off-center (bottom of the figures) region by the fact that the end walls 123 transition, via a concavely curved transition region 14, into pipe sockets 16 that form passages through the end walls 123 that are coaxial with each other and offset parallel to the axis of symmetry of the jacket 122.

[0029] The housing 12 is penetrated by a main pipe 18 that is fixed with its ends 181 in a force-fit, in particular clamping, manner in one of the respective pipe sockets 16. The frictional connection acts fully around the circumference of the main pipe 18, so that the passages formed by the pipe sockets 16 into the interior of the housing are thereby sealed. In the embodiment shown, the pipe sockets 16 project axially outward beyond the ends 181 of the main pipe 18. In this area, supply lines adapted in circumference to the main pipe 18 can be fixed by clamping and/or by material-fit (e.g. welding or bonding).

[0030] The wall of the main pipe 18 comprises several apertures that connect its interior with the interior of the housing in a fluid-conducting manner. The openings have different functions. The windows 182 arranged at the top and sides of the main pipe 18 in FIG. 2 allow sound waves to enter the interior of the housing, which acts as a resonator chamber. The holes 183 arranged at the bottom in FIG. 2, on the other hand, serve to extract liquid that may accumulate in the lower region of the resonator chamber and that is extracted due to the jet pump effect of the fluid flowing through the main pipe 18.

[0031] In the embodiment shown, the interior of the housing is divided into two separate resonator chambers by a partition wall 20. The partition wall 20 is in sealing contact with the main pipe 18 by which it is penetrated on the one hand, and with the inner wall of the jacket 122 on the other hand. Both sealing attachments preferably are made in a force-fit manner. However, a form fit is possible alternatively or preferably additionally. In the embodiment shown, this is realized in the area where the partition wall 20 abuts against the main pipe 18, as indicated by the magnifying window in FIG. 2. Here, the main pipe has radial projections 22 laterally of and adjacent to the partition wall 20, by means of which the axial position of the partition wall 20 is (additionally) secured.

[0032] FIGS. 3a-3g show details of the concave transition area between pipe socket 16 and end wall 123 by means of seven cross-sections through the sound reducer of FIGS. 1 and 2 along section lines IIIa to IIIg in FIG. 2. The completely undercut-free shaping of the half shells 12a, 12b can be seen, which makes it possible to manufacture these components as deep-drawn elements.

[0033] In the preferred manufacturing process, the partition wall 20 is first pressed onto the main pipe 18. For this purpose, a radial projection 22 previously applied to the main pipe 18 can serve as a stop for the press-on process. However, it is also possible to position the partition wall 20 precisely axially without such a radial projection. Then, on the other side of the pressed-on partition wall, a (further) radial projection 22 can be produced, for example by crimping or compressing the main pipe 18, in order to additionally fix the pressed-on partition wall axially in a form-fitting manner. This (further) projection can also be dispensed with if the press-fitting process is appropriately designed. The assembly part consisting of the main pipe 18 and the partition wall 20 is then inserted into one of the half shells 12a, 12b, the front end of the main pipe 18 being inserted from the inside (i.e. from the later interior of the housing) into the corresponding pipe socket 16 and pressed therewith. In the cross-section of FIG. 2, the assembly part consisting of main pipe 18 and partition wall 20 preferably is inserted into the half shell 12b on the right in FIG. 2. In the process, the outer edge of the appropriately dimensioned partition wall 20 also comes into sealing, frictional contact with the inner wall of the shell 122, which can (not shown in FIG. 2) be provided here with a stop to improve the sealing contact. However, such a stop should preferably be designed to be free of undercuts with regard to the manufacturing process of the half-shells. In a subsequent step, the second half-shell is pushed onto the free, rear end of the main pipe 18 in an analogous manner until the shell edges 121a, b lie against each other and can be welded together.

[0034] To connect the sound reducer 10 to a fluid line system, for example to the exhaust line of a motor vehicle or the refrigerant line of an air conditioning system, connection pipes on the system side can be inserted into the projecting areas of the pipe sockets and fixed there with a force fit and/or material bond. The inner and outer diameters of the connecting pipes preferably correspond to the inner and outer diameters of the main pipe 18 so that the flowing fluid has a constant channel diameter.

[0035] Of course, the embodiments discussed in the specific description and shown in the figures are only illustrative examples of embodiments of the present invention. One skilled in the art is provided with a wide range of possible variations in light of the present disclosure. In particular, it is not mandatory to make the jacket 122 cylindrical, as shown. In particular, with respect to a sealing abutment of the partition wall 20 against the inner wall of the jacket, it may be favorable to select a jacket shape that tapers conically toward the axially outward directions. Such a design also simplifies the formation of undercut-free stops for the abutment of the partition wall 20 against the inner side of the jacket 122.

LIST OF REFERENCE SIGNS

[0036] 10 sound reducer [0037] 12 housing [0038] 12a, b half shells [0039] 121a, b shell edges [0040] 122 jacket [0041] 123 end wall [0042] 14 transition region [0043] 16 pipe socket [0044] 18 main pipe [0045] 181 end of 18 [0046] 182 windows [0047] 183 hole [0048] 20 partition wall [0049] 22 radial projection