FR2909429A1 - Force transmission structure`s part assembling joint for vehicle, has sheath made of elastomeric material molded with insert and forming wall for hydraulic fluid chambers communicating with each other via channels - Google Patents

Abstract

The invention relates to a hydro-elastic articulation comprising at least one internal reinforcement (1), a cage (2), an outer sleeve (4), and a lining (5) made of elastomer material molded with at least one insert constituted by the cage (2) and delimiting hydraulic fluid chambers communicating with each other through channels.According to the invention, the assembly formed by the lining (5) and each insert has a reserve of axial molding to the inside which each chamber (6) and each channel (30) are closed off or delimited in an axial direction by closure means (3) filling for example the function of a fluid distributor.

Description

1 STRUCTURALLY OPTIMIZED HYDRO-ELASTIC JOINT AND METHOD THEREOF

MANUFACTURING.

  The invention generally relates to vibration control techniques, and in particular to a hydro-elastic articulation designed to assemble two parts of a force transmission structure, in particular of a motor vehicle, and to dampen vibrations transmitted from one of these parts to another. More specifically, the invention relates, according to a first of its aspects, a hydro-elastic articulation having first and second axial ends spaced from each other along a longitudinal axis, and comprising, at increasing radial distance of this axis, at least one internal reinforcement, an intermediate frame with a window or "cage", and an outer sleeve, this articulation further comprising a lining of molded elastomer material with at least one molding insert selected from the group consisting of internal frame, the cage and the outer sleeve, this lining at least partially forming a wall for at least two chambers of hydraulic fluid that interacts with each other through at least one channel.

  A hydro-elastic joint of this type is described in particular in the patent document; FR 2 830 911, other examples of joints being given in patent documents US Pat. No. 4,971,456, FR 2 853 379 and EP 0 499 996.

  Traditionally, the chambers of these joints are defined by reentrant radial spaces, dug between the arms of the cage. Correlatively, the manufacture of these joints requires the use of drawer molds, which have the disadvantage of being expensive, bulky and relatively complex use.

The invention is based on a questioning of the supposed inevitable character of the standard structure of the hydro-elastic joints, and the disadvantages associated with this structure.

To overcome these, the articulation of the invention, moreover in accordance with the generic definition given in the preamble above, is essentially characterized in that it further comprises closure means, in that The assembly formed by the packing and each insert has an at least substantially axial molding reserve, and in that each chamber and each channel are defined inside the mold reserve and are closed or delimited at In the preferred embodiment of the invention, the molding reserve and the closure means together define, in angular zones that are offset, one of the other around the longitudinal axis and alternately, at least two free spaces of higher volumes and two free spaces of lower volumes, each free space of higher volume accommodating at least one of said cham bres, and at least one free space of lower volume hosting said channel.

To do this, it is possible to provide that the molding reserve has, at the first axial end of the hinge, an opening which is closed axially by the closure means, this opening being for example annular.

On the other hand, the second axial end that each chamber has at the second axial end of the hinge may be closed axially by the lining. In at least one possible embodiment of the invention, the closure means comprise a plastic deformation of the outer sleeve resulting from a radial necking. In other possible embodiments of the invention, the closure means comprise, for example, an insert, driven axially into the molding reserve, this insert comprising at least one end blocking axially the opening of the reserve. molding. It is then conceivable to provide that the base of the insert has a peripheral groove in which is fitted the first axial end of the cage, and that this base forms a mechanical bridge between the first axial end of the cage and a first end. of the inner frame and / or the outer sleeve. The base of the insert may also have an inner flange radially closer to the axis than the first axial end of the cage and adapted to form a stop radial movement limitation of the inner armature relative to the sleeve. It is also possible to provide that the cage and the sleeve or the cage and the internal armature are connected to each other by their respective second axial ends and thus form a single piece.

Furthermore, the gasket may have at least one pressure relief valve adapted to communicate two chambers with each other directly in case of overpressure, the insert bearing an axial rib adapted to retain an edge of a lip of this valve.

In an advantageous embodiment of the invention, at least one of the elements constituted by the internal reinforcement, the cage, the sleeve, and the insert is made of a polymeric material, preferably by molding.

The invention further relates to a method of manufacturing a hydroelastic joint having first and second axially spaced apart ends along a longitudinal axis, and comprising, at increasing radial distance from this axis, at least one internal reinforcement, an intermediate frame with a window or "cage", and an outer sleeve, this articulation further comprising a lining of molded elastomer material with at least one molding insert selected from the group comprising internal frame, cage and outer sleeve, said liner at least partially forming a wall for at least two chambers of hydraulic fluid, characterized in that it comprises an operation of molding in one operation the packing on the cage and the outer sleeve and / or the inner frame.

In this case, the demolding operation can be performed by relative distance, along the longitudinal axis, of the mold and the assembly formed by the lining and each insert, possibly accompanied by a rotation about this axis and / or elastic deformation of the liner. Other characteristics and advantages of the invention will emerge clearly from the desc: iption which is made hereinafter, as an indication and in no way limiting, with reference to the accompanying drawings, in which: - Figure 1 is a view in axial section of a hinge according to a first possible embodiment of the invention; FIG. 2 is a cross-sectional view of the articulation illustrated in FIG. 1, this section being taken along the plane indicated by the arrows II-II of FIG. 1; FIG. 3 is a view in axial section of the articulation illustrated in FIG. 1, this section being taken along the plane indicated by the arrows III-III of FIG. 2; - Figure 4 is an axial sectional view of a hinge according to a second possible embodiment of the invention; FIG. 5 is a cross-sectional view of the articulation illustrated in FIG. 4, this section being taken along the plane indicated by the arrows V-V of FIG. 4; FIG. 6 is a view in axial section of the articulation illustrated in FIG. 4, this section being taken along the plane indicated by the arrows VIVI of FIG. 5; - Figure 7 is an exploded perspective view in partial section of a hinge according to a third possible embodiment of the invention; FIG. 8 is a perspective view of a single piece forming the cage and the outer sleeve of the articulation illustrated in FIG. 7, seen on the side of its first axial end; FIG. 9 is a perspective view of a single piece forming the cage and the outer sleeve of the articulation illustrated in FIG. 7, seen on the side of its second axial end; FIG. 10 is a perspective view of the part illustrated in FIG. 9, cut along an axial plane; - Figure 11 is a sectional view along an axial plane of the part illustrated in Figure 9; Figure 12 is a partially cut away perspective view of the liner and the set of inserts it presents in the third illustrated embodiment of the invention; - Figure 13 is a perspective view of the liner of a joint known in the prior art; FIG. 14 is a sectional view along an axial plane of the liner and the set of inserts it presents in the third illustrated embodiment of the invention; FIG. 15 is a cross-sectional view of the liner and the set of inserts which it presents in the third embodiment of the invention; - Figure 16 is a perspective view of the insert, forming a distributor; FIG. 17 is a view from above of the dispenser 10 illustrated in FIG. 16; Fig. 18 is an enlarged view of a detail of Fig. 16; - Figure 19 is a perspective view partially exploded and cut away of a hinge 15 according to the invention; - Figure 20 is a perspective view of a hinge according to the invention; Fig. 21 is a cross-sectional view of the hinge shown in Fig. 20; FIG. 22 is a sectional view of the articulation illustrated in FIG. 20, the section being taken along a first axial plane; FIG. 23 is another sectional view of the articulation illustrated in FIG. 22, the section being taken along a second axial plane different from the first one; - Figure 24 is a sectional view of a variant of the joint illustrated in Figures 22 and 23; Fig. 25 is an enlarged view of the detail indicated by XXV in Fig. 24; - Figure 26 is an axial sectional view of a hinge according to a fourth possible embodiment of the invention; FIG. 27 is a cross-sectional view of the articulation illustrated in FIG. 26, this section being taken along the plane indicated by the arrows XXVII-XXVII of FIG. 26; and FIG. 28 is a view in axial section of the articulation illustrated in FIG. 26, this section being taken along the plane indicated by the arrows XXVIII-XXVIII of FIG. 27. As previously announced, the invention relates to a hydro-elastic joint generally shaped hollow cylinder (Figure 20) and having. axial ends B and H spaced from each other along a longitudinal axis Y and by convention respectively designated as lower and upper. As shown in particular in FIGS. 1, 4, 7, and 26, this articulation comprises at least, at increasing radial distance from this axis Y, an internal reinforcement 1, an intermediate frame 2 with a window, and an external sleeve 4. L window frame 2, more commonly known as a "cage", may be essentially formed of two rings 20B and 20H connected by axial arms 21 (FIG. 11). This joint also comprises a lining 5 made of elastomeric material and, optionally, additional parts 7a to 7d (FIG. 7) which do not specifically belong to the invention.

The lining 5 is obtained by molding in a mold which are also introduced, as inserts, one or more elements selected from the assembly comprising the inner armature 1, the cage 2 and the outer sleeve 4.

This packing 5 at least partially forms a wall for a plurality of hydraulic fluid chambers 6, which communicate with each other at least in pairs through one or more channels 30. With this arrangement, the relative radial movements between the inner armature 1 and the outer sleeve 4 cause, in a manner known per se, volume variations of the different chambers, thus a flow of hydraulic fluid between the various chambers 6 through the channels 30 of the dispenser. Relative radial movements between the inner armature 1 and the outer sleeve 4 can thus be attenuated and frequency-filtered thanks to the inertial resistance offered by the channels 30 to the circulation of the fluid between the different chambers 6. The packing 5, which has an inner portion 51 10 and a peripheral portion 52, can in particular connect the cage 2 to the inner frame 1 (Figures 1, 4, 15) or connect the cage 2 to the outer sleeve 4 (Figure 26). In the first case, the peripheral portion 52 of the gasket 5 typically forms an inner wall 15 for the chambers 6, while in the second case, the inner portion 51 of the gasket 5 forms a radially outer wall for the chambers 6. In addition to the elements previously mentioned, the articulation comprises closure means 3, which can assume various forms. Furthermore, the assembly formed by the liner 5 and each insert has a molding reserve at least substantially axial. The "mold reserve" is the volume left free of any material in a molding operation, thanks to the presence in the mold of a core occupying this volume. By convention, a molding reserve "at least substantially axial" in the sense of the present description is a molding reserve which is strictly axial or which, failing this, has only helical radial cavities or of sufficiently large dimensions. low for the demolding operation can be performed by relative distance, along the longitudinal axis Y, of the mold and the assembly formed by the liner 5 and each insert, possibly accompanied by a rotation around this Y axis and / or elastic deformation of the liner 5. Each chamber 6 and each channel 30 can thus be defined inside the mold reserve and are closed or delimited, at least in an axial direction, by the shutter means 3. Each of the elements 1 to 5 of the joint has a lower axial end 1B to 5B, and an upper axial end 1H to 5H.

As shown in pairs in FIGS. 1 and 3, 4 and 6, 22 and 23, and 26 and 28, the molding reserve and the closure means 3 together define free spaces of different volumes in respective angular zones that are offset. one of the other around the longitudinal axis Y. The relatively large free spaces, each of which houses a chamber 60, alternate with the relatively small volume free spaces, at least one of which houses the channel 30.

More specifically, in the embodiments comprising two chambers 6 (FIGS. 1 to 6), the mold reserve and the closure means 3 together define two relatively large free spaces alternating with two relatively small volume free spaces. and in the embodiments comprising four chambers (FIGS. 7 to 12 and 14 to 28), the molding reserve and the closure means 3 together define four relatively large free spaces alternating with four relatively large free spaces. small. In all cases, the molding reserve has, at the lower axial end B of the joint, at least one opening 60 (see for example Figure 12) which allows the release of the liner 5 and the assembly 35 its inserts along the Y axis, and which is closed axially by the closure means 3.

This structure thus differs fundamentally from the structure of a known hinge as illustrated in FIG. 13, in which the lining 5 'defines chambers 6' each of which is bordered both axially and radially. As shown in particular in Figures 1, 4, 14, and 26, the opening 60 left by the molding reserve before the introduction of the closure means 3 may advantageously be annular.

Moreover, as shown by these same figures, the upper axial end 6H of each chamber 6 is preferably closed axially by the lining 5. In the embodiment illustrated in FIGS. 1 to 3, the closure means 3 are in fact constituted by a plastic deformation of the outer sleeve resulting from a radial necking. On the other hand, the free spaces of higher volume, which form the chambers 6 (FIG. 1), are obtained by providing that the lining 5, in the corresponding angular zones, extends axially only over a short distance and only near the upper end H of the joint, while the voids of lower volume, which form the channels 30 (Figure 3), are obtained by providing that the lining 5, in the corresponding angular areas, s' extends axially over a greater distance, from the upper end H to near the lower end B of the joint. The other figures, with the exception of FIG. 13 which does not relate to the invention, illustrate embodiments in which the closure means consist of an insert 3. This insert is pressed axially into the reserve. molding and comprises a base 31 which axially closes the opening 60 of this molding reserve.

In the embodiment illustrated in FIGS. 4 to 6, the free spaces of higher volume, which form the chambers 6 (FIG. 4), are obtained by providing that the insert 3, in the corresponding angular zones 5, does not extends axially only over a short distance and in the vicinity only: of the lower end B of the articulation, whereas the free spaces of lower volume, which form the channels 30 (FIG. 6), are obtained by providing that the In the corresponding angular areas, the inserted piece 3 extends axially over a greater distance, from the lower end B to near the upper end H of the hinge. Figures 7 to 12 and 14 to 25 illustrate a third embodiment for a hinge according to the invention, with more elaborate features which are detailed below. In this embodiment, and as best shown in FIGS. 14, 15, 16, 22, and 23, the fragmentation of the total volume, initially occupied by the molding reserve, in smaller volumes constituting chambers 6 and 30 is made almost exclusively by the insert 3 which thus acts as a distributor. Furthermore, to prevent damage to this joint in the event of a violent shock causing excessive overpressure of the fluid in one of the chambers 6, the Molded lining 5 has, in a manner known per se, one or more relief valves 53 adapted to communicate with each other, directly, two different chambers 6. As shown in particular in FIGS. 8 to 11, the cage 2 and the sleeve 4 are preferably connected to one another by their respective upper axial ends 2H and 4H, so that they form only one of the two elements. 12 only part and that they can be manufactured together, in particular by molding. More generally, the cage 2, the sleeve 4, the distributor 3 and / or the annular base 31 may advantageously be made of aluminum or of a polymeric material. These parts can be obtained by molding and have relatively elaborate forms allowing them to easily perform multiple functions.

The manufacture of the hinge can be further simplified by introducing the outer sleeve 4, as an additional insert, into the mold for molding the liner 5 of elastomeric material. The base 31 of the insert 3 takes the form of an annular flange forming an integral part of this part 3, the latter ensuring a: distributor function. This part or distributor 3, more specifically illustrated in FIGS. 16 to 18, has multiple functions and has a relatively elaborate structure for this purpose. Firstly, the collar 31 of this distributor 3 has an internal rim 311 disposed at a greater radial distance from the Y axis than the lower axial end 2B of the cage 2, this internal rim being intended to limit the deflection radial part 7a connected to the inner armature 1, and therefore to constitute a stop limiting the radial clearance of the inner armature 1 relative to the sleeve 4.

At its upper axial end 3H, the distributor 3 has pads 33 intended to be applied to the elastomer seal 5 to seal between the chambers 6 of each pair of adjacent chambers.

The flange 31 of the distributor 3 furthermore has an internal peripheral groove 312 in FIG. 23) 2909429 13 in which the lower axial end 2B of the cage 2, which is thus rigidly connected, is fitted by the base of the part. annular insert 3 that forms the flange 31, at the lower axial end 4B 4B of the sleeve 4. The distributor 3 has, on its inner face, bosses 35 parallel to the Y axis (at the draft angle by) and intended to be applied on the arms 21 of the cage 2 (FIG. 21) to ensure, on the one hand, the angular setting of the distributor 3 relative to the cage 2 around this axis Y and on the other hand the cohesion radial of this distributor and the cage vis-à-vis the radial forces exerted between the inner armature 1 and the sleeve 4.

In order to prevent an overpressure valve 53 of the molded lining 5 from being accidentally adhered to the internal face of the sleeve 4 during the molding of this lining, and to guarantee the geometry of this valve, each valve 53 is dimensioned so as to be separated by a non-zero distance from the inner face of the sleeve 4. It is then possible to provide that each valve 53 cooperates with the bottom of a countersink 32 dug in the inner face of the distributor 3 between two adjacent chambers, on the generator of a boss 35.

As a variant, the distributor may have a window instead of the counterbore, each valve 53 then cooperating directly with the internal face of the sleeve 4 as soon as this valve has been brought closer to this internal face by the radial stress which is applied to the articulation 30 before use. In both cases, the distributor 3 preferably carries an axial rib 321 adapted to retain the upper edge 531 of the lip of this valve 53. The flange 31 (Figure 23) comprises in. in addition to an external peripheral groove 313, in which the lower end 4B of the sleeve 4, 2909429 14 itself hollowed out by an internal peripheral groove 41 is applied, which is applied to a protuberance 314 of this collar 31. This arrangement leads to the development of an axial force 5 of support of the collar 31 against the respective ends 2B and 4B of the cage 2 and the sleeve 4, this support force can be used to ensure the axial compression of O-rings arranged on the one hand between the end 2B of the cage 2 and the collar 31 and on the other hand between the end 4B of the sleeve 4 and the same collar 31. The O-ring formed between the end 2B of the cage 2 and the flange 31, barely visible in FIGS. 22 and 23, is arranged at the bottom of the internal peripheral groove 312 of the flange 31 and clearly visible in FIG. 25 which illustrates a variant embodiment of the seal between 'extr mite 4B of the sleeve 4 and the flange 31. According to this variant, a thin layer of elastomer lining 5 is deposited on the inner lateral face of the sleeve 4 and in particular at the bottom of the inner peripheral groove 41 of this sleeve, the seal being made by radial compression of this lining layer 5 between the protrusion 314, in this case rounded, of the collar 31 and the bottom of the groove 41 of the sleeve 4. Finally, the external face of the distributor 3 is hollowed out with 34 for example evacuation formed on the back of the bosses 35 and the same direction, and allowing the hydraulic fluid present in excess of 30 chambers 6 to evacuate them during the introduction of the distributor 3 in the annular space 60 , while possibly applying a slight overpressure to the fluid remaining trapped. The method of manufacturing the hydroelastic joint corresponding in particular to this embodiment is preferably implemented by manufacturing the internal reinforcement 1, for example in the form of a section of metal tube, by manufacturing in one piece ( FIGS. 8 to 11) the cage 2 and the outer sleeve 4 by injection of aluminum or a mechanically resistant polymer into a first mold, by manufacturing the distributor 3 (FIGS. 16 to 18) by injection of aluminum or aluminum; a mechanically resistant polymer in a second mold, forming by molding in a third mold the lining 5 on the inserts constituted by the internal reinforcement 1, the cage 2 and the sleeve 4 (FIGS. 14 and 15), by unmolding this piece by relative distance, along the longitudinal axis Y, of the third mold and the gasket 5 with its inserts, immersing the molded part 15 with the gasket in the hydraulic fluid, and introducing the distributor r 3 and its closure flange 31 in the annular opening 60 of the molded part with the seal, still immersed in the hydraulic fluid. FIGS. 26 to 28 illustrate a fourth embodiment for a hinge according to the invention, in which the insert 3 also fulfills the role of distributor, at least in combination with the internal frame 1. In this embodiment , the inner armature 1 and the cage 2 are connected to each other by their respective upper axial ends 1H and 2H (Figure 28), so that they form a single piece and that they can be manufactured together, in particular by molding.

The insert 3, which forms a distributor, is inserted axially into the molding reserve between the internal reinforcement 1 and the cage 2, each chamber 6 thus having a radially inner wall partially formed by this part 3 and a wall radially. outer formed by the packing 5.

The molding reserve is thus divided into four chambers 6 which communicate with each other, at least in pairs, via channels 30 defined between the shoulders of the internal reinforcement 1 and the shoulders of the insert 3.

Claims (15)

  . A hydro-elastic articulation having first and second axial ends (B, H) spaced apart from each other along a longitudinal axis (Y), and comprising, at increasing radial distance from said axis, at least an internal frame (1), an intermediate frame (2) with a window or "cage", and an outer sleeve (4), this hinge also comprising a lining (5) made of molded elastomer material with at least one chosen molding insert in the assembly comprising the inner armature (1), the cage (2) and the outer sleeve (4), this lining (5) forming at least partially a wall for at least two chambers (6) of hydraulic fluid communicating the with each other through at least one channel (30), characterized in that it further comprises closure means (3), in that the assembly formed by the packing (5) and each insert has at least substantially axial molding reserve, and that each chamber (6) and each channel (30 ) are defined inside the mold reserve and are closed or delimited, at least in an axial direction, by the closing means (3).   2. hydro-elastic articulation according to claim 1, characterized in that the mold reserve and the closure means (3) define together, in angular zones offset from one another about the longitudinal axis ( Y) and alternately, at least two free spaces of higher volumes and two free spaces of lower volumes, each free space of higher volume accommodating at least one of said chambers (6), and at least one free space of lower volume accommodating said : channel (30).   3. hydro-elastic articulation according to any one of claims 1 and 2, characterized in that 2909429 18 the molding reserve has, at the first axial end (B) of the hinge, an opening (60) closed axially by the sealing means (3).   4. hydro-elastic articulation according to claim 3, characterized in that: said opening (60) is annular.   5. hydro-elastic joint according to any one of the preceding claims, characterized in that each chamber (6) has, at the second axial end (H) of the joint, a second axial end (6H) closed axially by the packing (5).   6. hydro-elastic articulation according to any one of the preceding claims, characterized in that the closure means (3) comprise a plastic deformation of the outer sleeve resulting from a radial recess.   7. hydro-elastic articulation according to any one of the preceding claims combined with claim 3, characterized in that the closure means (3) comprise an insert, driven axially into the mold reserve, this insert ( 3) comprising at least one base (31) axially closing the opening (60) of the molding reserve.   8. hydro-elastic articulation according to claim 7, characterized in that the base (31) of the insert (3) has a peripheral groove (312) in which is engaged the first axial end (2B) of the cage ( 2), and in that said base (31) forms a mechanical bridge between the first axial end (2B) of the cage (2) and a first end (1B, 4B) of the internal frame (1) and / or the outer sleeve (4). 35   9. hydro-elastic articulation according to any preceding claim combined with claim 7, characterized in that the base (31) of the insert (3) has an inner flange (311) radially closer to the axis (Y) than the. first axial end (2B) of the cage (2) and adapted to form a limit stop radial displacement of the inner armature (1) relative to the sleeve (4).   10. hydro-elastic articulation according to any one of the preceding claims, characterized in that the cage (2) and the sleeve (4) or the cage (2) and the inner frame (1) are connected one to the other by their respective second axial ends (2H, 4H; 2H, 1H) and form a single piece.   11. hydro-elastic joint according to any one of the preceding claims, characterized in that the lining (5) has at least one pressure relief valve (53) adapted to communicate two chambers (6) one with the other directly in case of overpressure, and in that the insert (3) carries an axial rib (321) adapted to retain an edge (531) 20 of a lip of the valve (53).   12. hydro-elastic articulation according to any one of the preceding claims, characterized in that: at least one of the elements constituted by the internal frame (1), the cage (2), the sleeve (4), and The insert (3) is made of a polymeric material, preferably by molding.   13. A method of manufacturing a hydroelastic joint having first and second axial ends (B, H) spaced from each other along a longitudinal axis. (Y), and comprising, at increasing radial distance from this axis, at least one internal reinforcement (1), an intermediate frame (2) with a window or "cage", and an outer sleeve (4), this articulation further comprising a liner (5) of elastomeric material molded with at least one molding insert selected from the group consisting of the inner frame (1), the cage (2) and the outer sleeve (4), said liner (5). ) at least partially forming a wall for at least two chambers (6) of hydraulic fluid, characterized in that it comprises an operation of molding in one operation the packing (5) on the cage (2) and on the sleeve external (4) and / or on the internal armature (1).   14. The manufacturing method according to claim 13, characterized in that the demolding operation is carried out by relative distance, along the longitudinal axis (Y), of the mold and of the assembly formed by the packing (5) and each insert (2, 1), possibly accompanied by a rotation around this axis (Y) and / or an elastic deformation of the lining (5). 15