FR2614674A1 - FLEXIBLE NOISE AND FLOW DAMPER HOSE FOR HYDRAULIC CONNECTIONS - Google Patents

Abstract

A SOFT HOSE 3 ABSORBING NOISE INTENDED TO BE INSERTED IN A DUCT FOR THE TRANSMISSION OF A FLUID AND MORE PARTICULARLY IN A DUCT FOR CONNECTION TO A TAP, INCLUDES AN EXTERNAL SEALING FLANGE 1 AND AN ELASTIC WALL 2 TIGHTLY CONNECTED WITH THE FLANGE DEFINING AN AIR POCKET C. THE WALL OF THE PIPE TAKES, IN THE ABSENCE OF HYDRAULIC PRESSURE, A CONVEX SHAPE WITH RESPECT TO THE INTERIOR WHICH ACTS ON THE OPEN SURFACE OF THE PASSAGE, IN THE SENSE THAT IT MAKES A SECTION OF THE PASSAGE OF SMALL DIMENSION IN RELATION TO THAT REQUIRED BY THE PRESSURE. WHEN THE OPERATING PRESSURE IS APPLIED, THE AIR FROM THE AIR CHAMBER IS COMPRESSED AND THE ELASTIC WALL BECOMES APPROXIMATELY CYLINDRICAL, AS THE LIMITED PASSAGE SECTION EXPANDS AND BECOMES LARGE ENOUGH FOR FLUID CIRCULATION. THE STRUCTURE OF THE SOFT PIPE ALLOWS TO INCREASE THE EFFICIENCY OF CUSHIONING BY THE AIR CHAMBER AND A REDUCTION OF DISTURBANCES TO THE WATER FLOW THANKS TO THE PRESENCE OF THE SOFT SHOCK ABSORBER HOSE.

Description

1.

  The present invention relates to pipes

  ples damping noise and flow disturbances-

  for hydraulic connections and, more particularly

  rement, a mechanical component for pipe of this type for insertion into a hydraulic pipe, more particularly

  rement for use in connection to a tap.

  The shock absorbing pipes are made of a ma-

  elastomeric material configured to be inserted into a hydraulic line, in most cases, into a fitting used to connect the end of a pipe

  flexible to its power source, in order to absorb

  ber rapid fluctuations in pressure and attenuate the noise level of the equipment. To execute this

  function, the shock absorber hoses are capable of trapping-

  ner a certain amount of air in a room defined by a flexible wall. This air functions as an extremely elastic "lung" which absorbs rapid pressure fluctuations under the effect of compression and expansion and prevents their transmission. The effectiveness of a shock absorber hose of this type depends mainly 2. on the quantity of air trapped, that is to say on the volume of the air chamber. In known embodiments, the deformable walls of these damping pipes form, in the absence of pressure, for the greater part of their extension, a cylinder having an internal diameter

  adequate to allow a channel of suitable size.

  Therefore, the cylinder has an outside diameter which is only relatively slightly less than

  that of the pipe in which the flexible pipe is in-

  serene. The air chamber consists of a torol-

  relatively limited dal, interposed between the cy-

  flexible lindrics and the pipe wall.

  As soon as the system pressure is between 300 and 400 kPa, the air surrounding the flexible wall is

  greatly compressed with two unfortunate consequences.

  On the one hand, the volume of the air chamber is greatly reduced and on the other hand, the flexible wall, initially of cylindrical shape, takes a notable concavity which is

  prone to vortices and cavities, hence the increase

  tion of the resistance opposed to the flow of the fluid

and noise generation.

  What you need is a cushioned hose

  higher efficiency without increase

manufacturing costs.

  According to the present invention, the flexible wall of the flexible pipe has, in the absence of hydraulic pressure, a strongly convex shape relative to the interior which is substantially curved towards its axis and which forms a limited section of channel, of small size. compared

  to that required under the expected hydraulic pressure.

  Because. of its distinct form and according to the pre-

  sente invention, the pipe defines, in the absence of pres-

  sion, a seemingly unacceptable throttling and too restrictive for the passage of fluid. However, when the system is subjected to operating pressure, this 3. causes the air in the chamber to be compressed by the deformation movement of the flexible wall of the pipe. The wall flexes to become approximately cylindrical under the expected normal operating pressure, and therefore stops the constriction. In this way, the flexible wall of the pipe takes a shape which causes a reduced disturbance of the flow of water, and at the same time, the air chamber defined by the flexible wall has a volume much larger than the corresponding volume. of the air pocket of a flexible pipe having the construction of the prior art and therefore offers efficiency

  much larger as a sound absorbing system.

  The present invention will be well understood during

  the following description made in conjunction with the drawings

  attached in which: Figure 1 is a longitudinal sectional view taken along line I-I of Figure 2 of a damper pipe according to the present invention; Figure 2 is a cross-sectional view taken along a line II-II of Figure 1;

  Figures 3 to 5 are cross-sectional views

  tudinal identical to those of Figure 1, a second, a third and a fourth embodiment of the present invention; Figure 6 is a longitudinal sectional view taken along line VI-VI of Figure 7 of a fifth embodiment incorporating external stabilizing fins; Figure 7 is a cross-sectional view taken along line VII-VII of Figure 6; Figure 8 is a longitudinal sectional view taken along line VIII-VIII of Figure 9

  of a sixth embodiment incorporating fins

  your internal stabilization; Figure 9 shows a segment of a cross section taken 4. along line IX-IX of Figure 8; and Figure 10 is a cross-sectional view similar to Figure 9, showing a seventh embodiment incorporating internal stabilizing fins. In Figures 1 and 2, the letter T indicates a pipe section (represented by a dashed line) into which the shock absorbing pipe has been inserted. This can generally represent any type of pipe in a hydraulic connection. One intended use concerns a section of

  eccentric coupling used to connect a robi-

  net at the power source, for example, a tap

bathtub mixture.

  The shock-absorbing pipe 3 is represented by the

  solid lines under the conditions of its installation when

  that it is not subjected to hydraulic pressure. The pipe 3 is made of elastic rubber or other suitable elastic material and has a sealing flange 1 dimensioned so as to be inserted in the pipe T by abutting against the latter in a leaktight manner. The flexible wall 2 extends between the two flanges 1 and has a shape

  appreciably convex relative to the longitu-

  interior dinal. In the form described, the section

  longitudinal of flexible wall 2 is approximate-

  lie an arc. Wall 2 defines a narrow passage in the cross-section of the pipe

  as illustrated in figure 2. The diameter of the step-

  wise is obviously insufficient to allow the not-

  wise of the expected hydraulic flow. In fact, in the form in which it is represented, the surface of the limited section of the wall 2 does not even reach the twentieth part of the surface of the pipe T. The pipe 3 is inserted into the pipe T 5. when it is empty, and for this reason, the chamber or pocket C forming between the walls of the pipe T, that is to say the flange 1 which is against it, and the wall

  flexible 2, fills with air at atmospheric pressure.

  This is intended to operate in an inner tube

  to get the effect of a noise damping pipe.

  As can be observed, the inner tube C has a much larger volume than that which would be encountered in

  a pipe of the conventional type, which has, at rest,

  kings substantially cylindrical flexible - and an outside diameter only slightly smaller than that of the pipe T.

  When the hydraulic pressure (included normal-

  between 300 and 400 kPa) is applied to line T

  and that the air present in the chamber C undergoes a compression

  corresponding sion, chamber C is reduced in volume

  and the flexible walls expand, taking the form

  indicated by line 2 'in phantom.

  Therefore, the diameter of the limited section

  defined by the flexible wall 2 increases and becomes sufficient

  to allow passage from the orifice

  tense. However, no concavity is formed in the flexible walls and therefore the flow

  is not disturbed by vortices and cavities.

  On the other hand, the volume of the air chamber C, reduced as a result of the pressure applied, becomes close to the volume

  already presented by the air chambers of the damped hoses

  sors known at rest, in idle conditions, and therefore is much larger than the volume of the air chamber of these known shock absorbers under the same pressure, which gives better efficiency at operating pressure. The effectiveness of the shock absorber hose

is considerably increased.

  In the embodiment shown in fig.

  res 1 and 2, the air chamber C is closed by a flange 1 6.

  resting on the inner surface of the wall of the container

  pick T. If one does not wish to depend on this seal to have an efficient operation of the damping pipe, one can use the second embodiment illustrated in FIG. 3 in which the flanges 11 are connected to the

  flexible wall 12 and are connected to the ends of a tu-

  be 13, which may be of metal, plastic or other suitable non-porous material, which closes the

  air chamber C without depending on external forces.

  In this case, the assembled pipe 11-13 can be inserted into the pipe T. In a similar manner, in a third mode

  shown in FIG. 4, the flanges 21 connected

  tees at the flexible wall 22 are closed, for example vulcanized inside the internal part of a tube

  made of elastomer 23 which closes the air chamber C. The chamber

  air breeze C can in this case also be divided into several sections; for example, the flexible wall 22 can form, relative to the center of the tube 23, a shape

  lenticular similar to those used in some

  some packing materials. In the second and third-

  me embodiments illustrated in Figures 3 and 4 and also in the form which is now discussed,

  o the air chamber C consists of a lenticular form

  air, the air trapped in chamber C can be replaced

  created by another gas. In addition, the chamber C can also be pressurized before introduction of the pressure into

  line T by closing the chamber in an environment

  under pressure or by introducing into chamber C

  a substance which is predisposed to emit progressively

a gas.

  In FIG. 5, the flexible wall 32 which connects the flanges 31, instead of having the shape of an arc of a circle, looks more like a hydrodynamic nozzle. In this case, under experimental conditions, one can obtain 7. an even smaller disturbance in terms of flow

  hydraulics through the shock absorber hose.

  embodiment, the flexible wall 32 expands less than the corresponding wall of the first three embodiments and the limited section is therefore larger than in the previous cases, remaining by itself insufficiently dimensioned for passage from

  the expected source. In this example, the air in the sec-

  tion limited represents about 1/9 of the surface of the pipe T. According to Figures 6 and 7, the flexible wall 42 connecting the outer flanges 41 has fins 43 which extend longitudinally and radially in the direction of the outside. The function of these fins is

  mainly to offer some resistance

  tudinal to the bending directed towards the outside of the wall 42 so as to avoid the deformation and the stresses for the flow of water in its interior. In addition, the fins 43 give the flexible wall 42 a certain support which allows this wall to have a minimum thickness to take full advantage of the possibility of deforming it locally and therefore increasing

the effectiveness of the flexible hose.

  Alternatively, as shown in figures

  8 and 9, the flexible wall 52 which connects the external flanges

  res 51 includes fins 53 which extend longitudinally

  radially and radially outward by forming links

  elastic sounds between diametrically opposite zones of the.

  flexible wall 52. The elastic action of the fins 53, which stiffen and lengthen when the flexible wall moves outward under the effect of pressure

  hydraulic, in addition to the damping effect of the

  air bre. As the elasticity of air is linear while the elasticity of elastomeric materials is not, the damping pipe illustrated in Figures 8 and 9 combines 8.

  timely effect of the two actions, allowing

  nir the very favorable effects of a modified shock absorber.

  As shown in FIG. 10, the flexible wall 62

  which connects the external flanges 61 may also include

  of the fins 63 directed inwards where

  the tubular element 64 is connected to the radial ends-

  ment interns fins 63. This embodiment is particularly advantageous when one wishes a

  moderation of the traction effect of the radial fins.

  Naturally, the different embodiments

  tion of the shock-absorbing pipe, shown separately according to

  the present invention, can be combined with each other.

  In this way, a damping pipe in the form of a pipe

  re hydraulic, according to FIG. 5, can have vulcanized tubular external walls according to FIG. 4 and / or comprise external fins according to FIGS. 6 and 7, or even internal fins according to FIGS. 8, 9 or 10. The presence of front fins 53 or 63 according to FIGS. 8 and 10 is compatible with the presence of external fins 43 according to FIGS. 6 and 7, or also external fins extending radially and

  transversely, or also external fins overlap

  pant longitudinally and transversely to define a

hive-like structure.

  It is also evident that other modes of

  are possible in the area of pre-

  invention. Various constructions can be adopted for the flexible wall and for the external flanges. For example, the flexible wall which has a section in

  circular cut can have a square or polygo-

  nale. Stiffening and strengthening elements

  that can be added to the shock absorber pipe in the different

  your indicated ways, can also have designs

miscellaneous.

26 1 4 6 7 4

9.

Claims (9)

  1 - Flexible pipe (3) damping the noise for insertion into a pipe connection (T), characterized in that it comprises: - annular external flanges (1) and a flexible tubular wall (2) which extends between the external flanges and which partially defines an air chamber (C), - the flexible wall of the flexible pipe having, in the absence of hydraulic pressure, a shape clearly convex relative to its radial center, which causes passage limited size compared to that required by the hydraulic source to be connected at the fitting.   2 - Pipe according to claim 1, characterized   in that the flexible wall has a longitudinal curvature   the, in a section in section, substantially similar to an arc.   3 - Pipe according to claim 1, character-   in that the flexible wall has the profile of a nozzle hydrodynamics (32).   4 - Pipe according to claim 1, characterized   in that the flexible wall has long fins   tudinal (43), substantially radial and directed towards outside.   - Pipe according to claim 1, character-   dried by flexible walls with long fins   gitudinal, substantially radial, directed towards the interior   laughing. 6 - Pipe according to claim 5, characterized   by fins (53) connecting zones diametrically op- flexible wall (52).   7 - Pipe according to claim 5, character-   laughed at by fins which are part of a tubular element interior area. 10.   8 - Pipe according to claim 5, character-   in that the flexible wall has fins   substantially radial outward.   9 - Pipe according to claim 5, character-   in that the outer flanges (21) are connected   to a rigid outer tubular wall (23).   - Pipe according to claim 9, character-   se in that the chamber delimited by the flexible wall and by the walls of the outer tube is filled with a gas   at a pressure higher than atmospheric pressure.   11 - Pipe according to claim 1, characterized in that the outer flanges are tightly connected to an outer tubular wall of a material sealing elastomer.   12 - Pipe according to claim 11, character-   laughed in that the flexible wall and the tubular walls ex-   t defined define a structure having a slow form cular.