Damping device

Abstract

The invention relates to a damping device, in particular for damping or preventing pressure surges, such as pulsations, in fluid supply circuits, preferably in the form of a silencer, having a damping housing (10) and a damping tube (28) running in the damping housing (10), which has an inlet (20) and an outlet (22) for the fluid flow to be damped, and having at least one branch opening (30), which produces fluid-conducting 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), characterised in that each branch opening (30) has a tubular connection part (32) of predeterminable length and diameter, which opens into the damping volume (38).

Description

[0001] Damping device

[0002] The invention relates to a damping device, in particular for damping or avoiding pressure surges, such as pulsations, in fluidic supply circuits, preferably in the form of a silencer, with a damping housing and a damping tube running in the damping housing, which has an inlet and an outlet for the fluid flow to be damped and with at least one branch opening which establishes a fluid-carrying connection between the interior of the damping tube and a damping volume enclosed between the damping tube and the damping housing.DE 10 2015 000 418 A1 discloses a damping device comprising a damping housing surrounding a damping chamber, which has at least one fluid inlet and one fluid outlet, as well as a damping tube located in the flow path between them. To form a Helmholtz resonator, the damping tube has, in a region within its length, at least one branch opening penetrating the tube wall and leading to a Helmholtz volume within the damping housing. A fluid filter is arranged in the flow path extending between the fluid inlet and fluid outlet within the damping housing. The integration of the fluid filter into the damping housing enables a particularly compact design while simultaneously increasing operational reliability by eliminating the otherwise necessary connecting piping between a filter and a damper.

[0003] DE 10 2009 021 683 A1 discloses a liquid silencer comprising a silencer housing with a main dimension defining a longitudinal axis of the housing and a damping tube extending in the direction of the longitudinal axis of the housing between an inlet opening and an outlet opening in the silencer housing, said damper having at least one radial opening. The liquid silencer has a device for changing the position and / or size of the opening in the damping tube. This makes it possible to adaptively optimize the damping of the liquid silencer during operation of the pressure fluid system.

[0004] DE 10 2018 003 848 A1 discloses a damping device, preferably in the form of a silencer, comprising a damping housing surrounding a damping chamber, which has at least one fluid inlet and at least one fluid outlet, as well as a fluid receiving chamber extending between the fluid inlet and the fluid outlet. During operation of the device, a fluid flow coming from the fluid inlet passes through the damping chamber toward the fluid outlet, and a wall portion of the fluid receiving chamber extends as a guide element in at least one direction of extension transverse to the direction of the fluid flow. Thus, a plurality of guide elements are preferably provided in the damping chamber, against which the fluid flow can flow and which vary its flow velocity in certain regions, thereby increasing the damping efficiency of the damping device.Due to this design of the damping device, at least the damping housing with the guide elements can advantageously be manufactured in a single piece using a 3D printing process. Based on this prior art, the object of the invention is to create a damping device with improved damping properties that can be manufactured easily and cost-effectively.

[0005] A damping device having the features of patent claim 1 in its entirety solves this problem.

[0006] Because, according to the characterizing part of patent claim 1, the respective branch opening has a tubular connecting part of a predeterminable length and diameter that opens into the damping volume, individual pipe sections are created which, as inherently vibrating bodies, dampen the fluid passing through them accordingly. Preferably, the longitudinal axis of each tubular connecting part is perpendicular to the longitudinal axis of the damping pipe, the orientation of which determines the main flow direction for the fluid passing through the damping pipe.

[0007] In particular, the respective branch opening in the damping tube merges seamlessly into the interior of the tubular connecting part, and the geometry of the branch opening is continued in the adjoining connecting part. Preferably, the respective tubular connecting part merges seamlessly and integrally into the damping tube in the area of ​​the associated branch opening, and all components of the damping device—the damping housing, the damping tube, and the branch openings along with the associated tubular connecting parts—are integrated into a single component. The aforementioned components can therefore be quickly and easily adapted to the actual conditions, which helps reduce manufacturing costs.

[0008] In a particularly preferred embodiment of the damping device according to the invention, several branch openings with their respective associated tubular connecting parts pass through the damping tube, and a specially designed connecting part is assigned to each individual frequency of the fluid flow to be damped. In this way, the frequency to be damped can be adjusted via the diameter and length of the respective tubular connecting part, creating a type of multi-Helmholtz resonator. However, to dampen a frequency range, a series of adjacent connecting parts of the same or different types is advantageous. One opening in the damping tube therefore dampens one frequency, and several openings with different cross-sections dampen a frequency range.

[0009] Preferably, 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 have different geometries, efficient damping can be achieved across a very wide frequency spectrum of the vibrations occurring in the fluid flow in the damping tube. In principle, the damping device can contain several connecting parts, particularly for high and low frequencies, which may not even be needed for a specific application; however, they may well be needed for a different application, in which case the tubular connecting parts intended for medium frequency ranges may not be needed.

[0010] Accordingly, the connecting parts with a small inner diameter and a long length are better suited for damping low frequencies of the fluid flow than connecting parts with a large inner diameter and a short length, which are preferably responsible for damping high frequencies.

[0011] In order to improve the damping effect when strong pressure pulsations occur in the fluid flow, it can preferably be provided to increase the wall thickness of the damping housing compared to the wall thickness of the damping tube.

[0012] If several connecting parts of different designs are arranged in a row along the damping tube, maintaining discrete spacings from one another, which are preferably equal, and if another row of connecting parts is present on opposite sides of the damping tube next to the one row, a highly reliable damping can be achieved within a very broad frequency spectrum for the fluid with low natural vibration behavior of the damping tube. With regard to the desired vibration behavior, it has proven advantageous to design the number of connecting parts in one row differently from the number of connecting parts in the other row.

[0013] In a particularly preferred embodiment of the damping device according to the invention, the damping housing and the damping tube with its connecting parts are manufactured in one piece using an additive manufacturing process, which allows the size of the damping device to be adapted to a variety of applications at low manufacturing costs without having to deviate from the basic design of the damping device. This has no equivalent in the prior art.

[0014] In another particularly preferred embodiment of the damping device according to the invention, the damping volume defined by the damping housing and the damping tube is designed toroidally, with a greater longitudinal extent parallel to the possible fluid flow direction than transverse to it. Particularly in the area of ​​the deflection points in the damping housing, i.e., in the area of ​​the inlet and outlet of the damping tube, a more even flow of the fluid introduced into the damping chamber via the tubular connecting parts is achieved, which increases the overall damping performance of the damping device according to the invention.

[0015] In the following, the damping device according to the invention is explained in more detail using an embodiment according to the drawing.

[0016] Figure 1 shows the damping device as a whole in a reduced scale and in perspective view; and

[0017] Figure 2 is an enlarged longitudinal section through the damping device according to Figure 1.

[0018] Figure 1 shows the damping device as a whole on a smaller scale than Figure 2 and in a perspective external view. The cylindrical damping housing 10 is formed on the outside with a smooth outer wall 12 and is constructed symmetrically. Towards the free end faces of the damping housing 10, the outer wall 12 tapers in an arc-shaped manner into a front end wall 14, through which a central opening 16 passes, with a received internally threaded part 18, which serves to connect a piping (not shown in detail), which, as part of a fluidic supply circuit, supplies a fluid flow to be smoothed or dampened, which is thus freed from pressure surges such as pulsations and is led out of the damping housing 10 opposite.In this case, as viewed in the direction of the figures, the right-hand central opening 16 forms the fluid inlet 20 for the fluid flow, and the central opening 16 on the left, which is of identical design, serves as the fluid outlet 22, through which the fluid flow is led out of the damping housing 10. However, given the axially symmetrical design of the damping device as a whole, it is also possible to reverse the flow direction, so that fluid flows in via the outlet 22 and out of the damping housing 10 via the inlet 20.

[0019] As shown in particular in longitudinal section in Figure 2, the damping housing 10 has a central cylindrical wall section 24 with a constant wall thickness, and this wall section 24 merges at the end in the direction of the respective end wall 14 into a type of cover part 26 with a comparatively increased wall thickness. A cylindrical damping tube 28 runs through the damping housing 10 as a whole, which merges at the end into an associated cover part 26, and at the free end faces, the damping tube 28 opens into the respective internally threaded part 18, which is thus received in the respective cover part 26. In its central receiving area, the damping tube 28 has a wall thickness that is somewhat greater than the wall thickness along the cylindrical wall section 24 of the damping housing 10. In this respect, the damping tube 28 is also connected to the inlet 20 and the outlet 22 of the damping housing 10.As further shown in Figure 2, individual through-branch openings 30 with a predeterminable inner diameter are provided in the damping tube 28. Adjoining the respective branch opening 30, preferably integrally connected to the damping tube 28, are individual tubular connecting parts 32 whose axial length can be predetermined, but whose inner diameter is adapted to the inner diameter of the respective branch opening 30.

[0020] As can also be seen from Figure 2, the individual longitudinal axes 34 of branch opening 30, along with the associated connecting part 32, are perpendicular to the central axis 36 of the damping tube 28, along which the fluid flow to be damped flows from the inlet 20 toward the outlet 22. This results in a sharp, right-angled deflection of the fluid flow from the damping tube 28 toward the respective outlet of a tubular connecting part 32 to a damping volume 38 located between the damping tube 28 and the inner peripheral damping housing 10. Thus, each connecting part 32 forms a fluid-carrying tubular connection between the interior of the damping tube 28 and the damping volume 28 designated therein, into which fluid flows from the damping tube 28 during operation of the damping device.

[0021] In this respect, several branch openings 30 with their respective associated tubular connecting parts 32 pass through the damping tube 28, and each frequency range to be damped or each individual frequency of the fluid flow is assigned a specially designed connecting part 32, which is of different lengths and, together with the associated branch opening 30, defines a discrete diameter for the fluid branching from the main fluid flow in the damping tube 28. Preferably, according to the illustration in Figure 2, all connecting parts 32 with their branch openings 30 are geometrically different from one another in order to enable a wide frequency range of fluid pulsations to be damped or smoothed.Tests have shown that connecting parts 32 with a small inner diameter and a long length dampen low frequencies of the fluid flow better than connecting parts 32 with a large inner diameter and a short length, which are primarily responsible for damping high frequencies. Furthermore, to improve the damping effect when strong pressure pulsations occur in the fluid flow, the wall thickness of the tubular connecting parts can be increased compared to the wall thickness of the damping tube 28. In the present exemplary embodiment, however, it is provided for the damping that the wall thickness of the tubular connecting part 32 is thinner than the wall of the damping housing 10 and that of the damping tube 28. In this respect, however, the selected wall thickness is the same for all connecting parts 32, as used in the damping housing 10 according to Figure 2.Furthermore, it has proven advantageous for the damping effect if several connecting parts 32 of different designs are arranged in a row along the damping tube 28 while maintaining discrete, preferably equal, spacings from one another. Thus, as viewed in the direction of Figure 2, the damping tube 28 has two connecting parts 32 on its upper side along with associated branch openings 30 in the damping tube 28. In contrast, the damping tube 28 has another row of connecting parts 32 on the opposite, lower side, this time in the form of three connecting parts 32 along with associated branch openings 30.

[0022] The damping volume 38 delimited by the damping housing 10 and the damping tube 28 is designed toroidally, ie in the transition area between the cylindrical wall section 24 and the cover parts 26, the inner wall of the damping housing 10 is designed such that a torus-like fluid space is created for the damping volume 38 and the annular, concave receiving areas formed in the cover part 26 allow the damping effect for the fluid to be improved even further.

[0023] The damping device according to the figures is manufactured in one piece using an additive manufacturing process, for example, within the framework of a selective laser sintering process from a metal material. This additive manufacturing process is mentioned only as an example, and other suitable 3D manufacturing processes can be used here. In this respect, the damping housing 10 and the damping tube 28 with all its connecting parts 32 are manufactured in one piece, and the two connections in the form of the internally threaded parts 18 allow the assembly and positioning of the silencer to be manufactured within the manufacturing space of the additive manufacturing machine in a particularly simple manner. In this way, the central damping tube 28 with the tubular connecting parts 32 to be attached to the respective branch opening 30 can also be obtained in a particularly advantageous manner.The tubular connecting parts 32 are designed as hollow cylinders, preferably with a circular cross-section. Due to the 3D process, however, the circular shape can be approximated by a polygon.

[0024] Overall, the additive manufacturing process produces a damping device as a whole whose dimensions, including all its components, can be cost-effectively adapted to a wide range of applications. This has no equivalent in the state of the art.

Claims

Patent claims for a damping device, in particular for damping or avoiding pressure surges, such as pulsations, in fluidic supply circuits, preferably in the form of a silencer, with a damping housing (10) and a damping tube (28) running in the damping housing (10), which has an inlet (20) and an outlet (22) for the fluid flow to be damped and with at least one branch opening (30) that establishes a fluid-carrying 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 the respective branch opening (30) has a tubular connection part (32) of a predefinable length and diameter, which opens into the damping volume (38).A damping device according to claim 1, characterized in that several branch openings (30) with their respective associated tubular connection parts (32) extend through the damping tube (28) and that each individual frequency or frequency range of the fluid flow to be damped is assigned a specially designed connection part (32) or a series of connection parts (32). A damping device according to claim 1 or 2, characterized in that at least some of the connection parts (32) used are geometrically different from one another, preferably that all connection parts (32) are different from one another. A damping device according to any one of the preceding claims, characterized in that the connection parts (32) with a small inner diameter and large length are better suited for damping low frequencies of the fluid flow. Fluid flow damping is achieved by connection parts (32) with a large inner diameter and short length, which are responsible for damping high frequencies. A damping device according to one of the preceding claims, characterized in that, to improve the damping effect when strong pressure pulsations occur in the fluid flow, the wall thickness of the damping housing (10) is increased compared to the wall thickness of the damping tube (28). A damping device according to one of the preceding claims, characterized in that several connection parts (32) of different designs are arranged in a row along the damping tube (28) while maintaining discrete distances from one another, which are preferably equal. A damping device according to one of the preceding claims, characterized in that, on opposite sides of the damping tube (28), a further row of connection parts (32) is provided in addition to the first row.A damping device according to one of the preceding claims, characterized in that the number of connection parts (32) of one row differs from the number of connection parts (32) of a subsequent row. A damping device according to one of the preceding claims, characterized in that the damping housing (10) and the damping tube (28) with its connection parts (32) are manufactured in one piece by means of an additive manufacturing process. Damping device according to one of the preceding claims, characterized in that the damping volume (38) bounded by the damping housing (10) and damping tube (28) is designed toroidally with a greater longitudinal extent parallel to the fluid flow direction than perpendicular to it.

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