Damping Device

Abstract

Specifically, the damping device, advantageously in the form of a silencer, for damping or avoiding pressure impulses such as pulsations in a fluid supply circuit, comprises a damping housing (10), a damping tube (28) extending in the damping housing (10) having an inlet (20) and an outlet (22) for the fluid flow to be damped, and at least one branch opening (30), the branch opening forming a fluid-guiding connection between the interior of the damping tube (28) and a damping volume (38) enclosed between the damping tube (28) and the damping housing (10), characterized in that each of the branch openings (30) has a tubular connecting portion (32) with a definable length and a definable diameter, the connecting portion opening into the damping volume (38).

Description

[Technical field]

[0001] The invention specifically relates to a damping device, advantageously in the form of a silencer, for damping or avoiding pressure impulses such as pulsations in a fluid supply circuit, comprising a damping housing, a damping tube extending within the damping housing having an inlet and an outlet for the fluid flow to be damped, and at least one branching opening, the branching opening forming a fluid-guiding connection between the interior of the damping tube and a damping volume enclosed between the damping tube and the damping housing. [Background technology]

[0002] The damping device known from DE 10 2015 000 418 A1 comprises a damping housing enclosing a damping space, the damping housing having at least one fluid inlet and fluid outlet as well as a damping tube located between them in a flow path, the damping tube having at least one branch opening through the tube wall in a region located within its length to form a Helmholtz resonator and leading to a Helmholtz volume inside the damping housing, and a fluid filter is arranged in the flow path extending between the fluid inlet and the fluid outlet inside the damping housing. The integration of the fluid filter into the damping housing allows a particularly compact construction and increases operational reliability by eliminating the need for connecting piping between the filter and the damper that would otherwise be necessary.

[0003] A liquid sound damper is known from DE 10 2009 021 683 A1, which comprises a damping tube having a main dimension defining a housing longitudinal axis and at least one radial opening extending in the damper housing in the direction of the housing longitudinal axis between an inlet opening and an outlet opening, the liquid sound damper comprising a device in the damping tube for varying the position and / or size of the opening. In this way, it is possible to adaptively optimize the damping of the liquid sound damper during operation of the pressure fluid system.

[0004] A damping device, preferably in the form of a silencer, known from DE 10 2018 003 848 A1, comprises a damping housing surrounding a damping space, which has at least one fluid inlet and at least one fluid outlet as well as a fluid receiving space extending between the fluid inlet and the fluid outlet, and during operation of the device, a fluid flow comes from the fluid inlet, crosses the damping space and goes to the fluid outlet, and a wall part of the fluid receiving space extends as a guiding element in at least one direction of extension transverse to the direction of the fluid flow. Thus, in the damping space, advantageously a number of guiding elements are provided, by which the fluid flow can flow and which vary the flow rate of the fluid flow in different regions. This increases the damping efficiency of the damping device. Based on such a form of the damping device, at least the damping housing can be advantageously additively manufactured in a 3D printing method, being integrally formed with the guiding element. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] DE 10 2015 000 418 A1 [Patent Document 2] DE 10 2009 021 683 A1 [Patent Document 3] DE 10 2018 003 848 A1 Summary of the Invention [Problem to be solved by the invention]

[0006] Starting from this prior art, the object underlying the invention is to provide a damping device which can be manufactured easily and inexpensively and which has improved damping properties compared to the prior art. [Means for solving the problem]

[0007] This problem is solved by a damping device having the features of claim 1 as a whole. Effect of the Invention

[0008] According to the characterizing feature of claim 1, the respective branch opening has a tubular connecting portion with a definable length and a definable diameter, which opening into the damping volume provides an individual tube piece which, as a vibrable body in itself, correspondingly damps the fluid flowing through it. Advantageously, the longitudinal axis of each tubular connecting portion lies perpendicular to the longitudinal axis of the damping tube, the longitudinal axis of which has an orientation defining a main flow direction for the fluid crossing the damping tube.

[0009] In particular, the respective branch opening of the damping tube seamlessly transitions into the inner space of the tubular connecting part, and the geometric shape of the branch opening is continued in the subsequently provided connecting part. Advantageously, the respective tubular connecting part transitions integrally and seamlessly into the damping tube in the area of ​​the assigned branch opening, and all components of the damping device in the form of a branch opening, including the damping housing, the damping tube as well as the assigned tubular connecting part, are integrated as one component. Thus, said components can be quickly and easily adapted to actual conditions, which helps to reduce production costs.

[0010] In a particularly advantageous embodiment of the damping device according to the invention, the damping tube is penetrated by a respective assigned tubular connection section of a number of branching openings, with a specially formed connection section being assigned to each individual frequency of the fluid flow to be damped. In this way, the frequencies to be damped can be adjusted over the entire diameter and length of the tubular connection section, so that a kind of multi-Helmholtz resonator is generated. However, to damp a frequency range, a row of connection sections, of the same or different types, arranged next to each other, is preferred. An opening of the damping tube thus damps a frequency, and a number of openings with different cross sections damp a frequency range.

[0011] Advantageously, at least some of the connecting parts used are geometrically different from one another, and preferably all of the connecting parts are different from one another. If all of the connecting parts are formed differently from one another in terms of their geometric shape, then it is possible to efficiently damp a very wide frequency spectrum of the fluid flow vibrations occurring in the damping tube. In principle, several connecting parts, in particular for high and low frequencies, can be provided inside the damping device, which may not be required at all for a particular application case, but are very often required in other applications. There may well be cases in which a tubular connecting part provided for the mid-frequency range is not required.

[0012] Thus, the connection portion with a small inner diameter and a large length is advantageously suited to attenuate low frequencies of the fluid flow better than a connection portion with a large inner diameter and a short structural length, which is responsible for attenuating high frequencies.

[0013] In order to improve the damping effect in the event of strong pressure pulsations in the fluid flow, it may be advantageous if the wall thickness of the damping housing is made thicker in relation to the wall thickness of the damping tube.

[0014] If connecting parts of different shapes are arranged in a row along the damping tube while maintaining an individual mutual distance, said distance being preferably equal, and if a further row with connecting parts is provided on the opposite side of the damping tube next to the first row, then reliable damping can be achieved on a large scale within the very broadly drawn frequency spectrum of the fluid in the presence of slight natural vibration behavior of the damping tube. It has been found to be advantageous from the viewpoint of the desired vibration behavior to design the number of connecting parts in a row differently from the number of connecting parts in the further row.

[0015] In a particularly advantageous embodiment of the damping device according to the invention, the damping housing and the damping tube together with the connection part of the damping tube are manufactured in one piece by additive manufacturing, which makes it possible to adapt the structural dimensions of the damping device to many application cases without having to change the basic structure of the damping device and at low manufacturing costs, which is not found in the prior art.

[0016] In a further particularly advantageous embodiment of the damping device according to the invention, the damping volume bounded by the damping housing and the damping tube is configured toroidally with a longitudinal extension parallel to the possible fluid flow direction that is greater than transverse to said fluid flow direction. In particular, in the region of the deflection points of the damping housing, i.e. in the region of the inlet and outlet of the damping tube, a homogenized flow guidance of the fluid introduced via the tubular connections into the damping space is provided. This increases the overall damping performance of the damping device according to the invention.

[0017] The damping device according to the invention is explained in more detail below on the basis of an embodiment shown in the drawing. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a reduced perspective view of the entire damping device. [Diagram 2] FIG. 2 is an enlarged longitudinal sectional view of the damping device shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] FIG. 1 shows a perspective external view of the entire damping device, reduced in scale with respect to FIG. 2. The cylindrical damping housing 10 is formed with an outer wall 12 that is smooth towards the outside and is constructed symmetrically. Towards the free end of the damping housing 10, the outer wall 12 runs in a rounded arc and ends in an end-side closing wall 14. The closing wall 14 is pierced by a central opening 16 in the middle, into which an internal threaded section 18 is received. The internal threaded section serves for the connection of a pipe, not shown in detail. The pipe, as part of a fluid supply circuit, supplies the fluid flow to be smoothed or damped. This fluid flow is thus relieved of pressure impulses, such as pulsations, and the fluid flow is again led away from the damping housing 10 on the opposite side. As viewed towards the drawing, the central opening 16 on the right side forms a fluid inlet 20 for the fluid flow, and the central opening 16 on the left side, which is formed in the same way in this respect, serves as a fluid outlet 22. Via this fluid outlet, the fluid flow is again led away from the damping housing 10. However, in view of the axially symmetrical construction of the entire damping device, it is also possible to reverse the flow direction so that the fluid enters via the outlet 22 and leaves the damping housing 10 via the inlet 20.

[0020] In particular, as shown in FIG. 2 in longitudinal section, the damping housing 10 has a central cylindrical wall section 24 with a constant wall thickness, which merges at the end in the direction of the respective end-side closing wall 14 into a kind of lid section 26 with an enlarged wall thickness in relation to the wall section 24. A cylindrical damping tube 28 runs through the damping housing 10 as a whole. At the end, the damping tube merges into each assigned lid section 26, and at the free end, the damping tube 28 opens into the respective internal thread section 18, which is thus received in the respective lid section 26. In its central receiving area, the damping tube 28 has a wall thickness that is in each case selected to be somewhat thicker than the wall thickness along the cylindrical wall section 24 of the damping housing 10. As such, the damping tube 28 is also connected to the inlet 20 as well as to the outlet 22 of the damping housing 10. As can further be seen from Fig. 2, individual through branch openings 30 are introduced into the attenuation tube 28 with a definable inner diameter. Each branch opening 30 is followed by an individual tubular connecting portion 32, which is advantageously integrally connected to the attenuation tube 28. The axial structural length of the tubular connecting portion is definable, but the inner diameter of the tubular connecting portion is equal to the inner diameter of the respective branch opening 30.

[0021] As can be seen further from FIG. 2, the respective longitudinal axis 34 of the branch opening 30 with the assigned connecting portion 32 lies perpendicularly on the central axis 36 of the damping tube 28. Along the central axis of the damping tube the fluid flow to be damped reaches in the direction from the inlet 20 to the outlet 22. As such, the fluid flow leaves the damping tube 28 and in the direction of the respective outlet of the tubular connecting portion 32 makes a sharp right-angled turn towards the damping volume 38, which is located between the damping tube 28 and the damping housing 10 on the inner circumference side. As such, each connecting portion 32 forms a fluid-conducting pipe connection between the interior of the damping tube 28 and the thus designated damping volume 28, into which the fluid from the damping tube 28 flows correspondingly later during operation of the damping device.

[0022] As such, the respective assigned tubular connection parts 32 of the multiple branch openings 30 penetrate the attenuation tube 28, with a uniquely formed connection part 32 being assigned to each frequency range or each individual frequency of the fluid flow to be attenuated. The connection parts 32 are thus formed with different lengths and together with the assigned branch openings 30 partition individual diameters for fluid branching from the main fluid flow in the attenuation tube 28. Advantageously, as shown in FIG. 2, all connection parts 32, including the branch openings 30, differ from each other in terms of their geometric shape, thus allowing further frequency ranges of fluid pulsations to be attenuated or smoothed. Tests have shown that connection parts 32 with a small internal diameter and a large length attenuate low frequencies of the fluid flow better than connection parts 32 with a large internal diameter and a short length, which are predominantly involved in attenuating high frequencies. Furthermore, in order to improve the attenuation action when strong pressure pulsations in the fluid flow occur, the wall thickness of the tubular connection parts can be thickened with respect to the wall thickness of the attenuation tube 28. However, for damping purposes in this embodiment, the wall thickness of the tubular connecting portions 32 is made thinner than the wall of the damping housing 10 and the wall of the damping tube 28. As such, however, the wall thickness selected for all connecting portions 32 is made the same with respect to wall thickness as used in the damping housing 10 shown in FIG.

[0023] Furthermore, it has been found to be advantageous for the damping action if a number of connecting portions 32 having different configurations are arranged in a row along the damping tube 28 while maintaining an individual mutual spacing, which spacing is advantageously equal. For example, looking towards Fig. 2, the damping tube 28 has on its upper side two connecting portions 32 with assigned branch openings 30 in the damping tube 28. In contrast to this, on the opposite lower side the damping tube 28 has a further row with connecting portions 32, here in the form of three connecting portions 32 with assigned branch openings 30.

[0024] The damping volume 38 bounded by the damping housing 10 and the damping tube 28 is configured toroidally, i.e. in the transition area between the cylindrical wall section 24 and the lid part 26, the inner wall of the damping housing 10 is shaped in such a way that a torus-shaped fluid space arises for the damping volume 38 and the ring-shaped concave receiving area thus formed in the lid part 26 allows for still further improvement of the damping action for the fluid.

[0025] The illustrated damping device is manufactured in one piece by additive manufacturing, for example from a metallic material within the framework of selective laser sintering. Such additive manufacturing is given by way of example only, and other suitable 3D manufacturing methods can also be used here. In this way, the damping housing 10 as well as the damping tube 28 are manufactured in one piece together with all the connection parts 32 of the damping tube 28, and both connections in the form of an internal thread 18 make it particularly easy to construct and position the muffler to be manufactured inside the production space of an additive manufacturing machine. In this way, the central damping tube 28 with the tubular connection parts 32 to be attached to the respective branch openings 30 can also be obtained particularly inexpensively.

[0026] The tubular connecting part 32 is designed as a hollow cylinder, preferably with a circular through-passage cross-section, however, with 3D methods the circular shape can be approximated by a polygon.

[0027] Overall, additive manufacturing provides an entire damping device that can be inexpensively adapted to numerous use cases with all its components in terms of construction dimensions, something that has no equivalent in the prior art.

Claims

1. A damping device, more specifically, a damping device for damping or avoiding pressure shocks such as pulsations in a fluid supply circuit, preferably in the form of a silencer, comprising a damping housing (10) and a damping tube (28) having an inlet (20) and an outlet (22) for a fluid flow to be damped, the damping tube (28) extending within the damping housing (10), wherein the damping tube (28) comprises at least one branch opening (30), the branch opening (30) forming a fluid guide connection between the interior of the damping tube (28) and a damping volume (38) confined between the damping tube (28) and the damping housing (10), in a damping device of the type described above. An damping device characterized in that each of the at least one branch opening (30) has a tubular connecting portion (32) having a defined length and a defined diameter, and the tubular connecting portion (32) opens into the damping volume (38).

2. The damping device according to claim 1, characterized in that each of the multiple branch openings (30) has an assigned tubular connection portion (32) that penetrates the damping pipe (28), and that a connection portion (32) or a row of connection portions (32) is assigned to each individual frequency or frequency range of the fluid flow to be damped.

3. The damping device according to claim 1, characterized in that at least a portion of the connecting portions (32) used are geometrically different from each other, and advantageously all of the connecting portions (32) are different from each other.

4. The attenuation device according to claim 1, characterized in that a connecting portion (32) having a small inner diameter and a large length attenuates the low frequencies of the fluid flow better than a connecting portion (32) having a large inner diameter and a short length that is involved in attenuating high frequencies.

5. The damping device according to claim 1, characterized in that the wall thickness of the damping housing (10) is formed to be thicker than the wall thickness of the damping pipe (28) in order to improve the damping effect when strong pressure pulsations occur in the fluid flow.

6. The damping device according to claim 1, characterized in that a plurality of connecting portions (32) having different shapes are arranged in a single row along the damping tube (28) while maintaining individual intervals between them, and the intervals are advantageously equal.

7. The damping device according to claim 6, characterized in that a further row having a connecting portion (32) is provided on the opposite side of the damping tube (28) in the same row as the one row.

8. The damping device according to claim 7, characterized in that the number of connection portions (32) in one row is different from the number of connection portions (32) in the further rows.

9. The damping device according to claim 1, characterized in that the damping housing (10) and the damping tube (28) are integrally manufactured together with the connecting portion (32) of the damping tube by an additive manufacturing method.

10. The damping device according to any one of claims 1 to 9, characterized in that the damping volume (38), partitioned by the damping housing (10) and the damping tube (28), is configured in a toroidal shape such that, when viewed parallel to the fluid flow direction, it has a longitudinal extension greater than the transverse extension with respect to the fluid flow direction.

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