DAMPING SYSTEM COMPRISING A DUAL-WAY HYDRAULIC DAMPER BODY

Abstract

The invention relates to a damping system (1, 1A) comprising a hollow cylindrical double-walled damper body (2) delimiting an internal volume (3) filled with a damping fluid, a piston assembly comprising a piston (5) arranged to delimit the internal volume into a compression chamber (30) and an expansion chamber (31), the damper body (2) comprising an internal wall (20) and an external wall (21), concentric, delimiting between them a circulation channel for the damping fluid, the damper body (2) having a radial partition (7) connecting the external and internal walls in a sealed manner and dividing the circulation channel into two hydraulic paths distinct from each other and communicating with the compression chamber (30) and the expansion chamber (31), the external wall (21) comprising at least two radial orifices each opening onto one of the hydraulic paths.Figure to be published with the abbreviation: Fig. 1.

Description

Title of the invention: DAMPING SYSTEM COMPRISING A DOUBLE HYDRAULIC SHOCK ABSORBER BODY TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the field of damping systems for vehicles, and in particular for cycles and the like.

[0002] The invention relates more particularly to a damping system comprising a hollow cylindrical double-walled damper body delimiting an interior volume filled with a damping fluid, a piston assembly comprising a piston rod mounted to slide axially through the damper body and a piston, integral with the piston rod, arranged within the interior volume so as to delimit the latter into a compression chamber and an expansion chamber, the damper body comprising an internal wall and an external wall, concentric, delimiting between them a corridor for circulation of the damping fluid, communicating with the compression chamber and the expansion chamber. STATE OF THE ART

[0003] Double-walled shock absorbers (commonly referred to as "twin tube shock absorbers") comprise an inner tube delimiting a volume of internal fluid (oil), an outer tube delimiting a fluid circulation corridor, at least one flow passage extending through the inner tube to allow fluid communication between said volume of internal fluid and the fluid circulation corridor. These shock absorbers are further provided with a remote reservoir (commonly referred to as a "piggy back") for managing the fluid contained in the internal volume when the shock absorber is compressed. The reservoir is mounted at the end of the shock absorber and connected to the volume of internal fluid and to the fluid circulation corridor by at least one orifice provided at the end. During the compression phase, the fluid is sent to the piggy back to return to the expansion chamber via the fluid circulation corridor delimited by the outer tube.

[0004] The disadvantage of double-walled shock absorbers lies in the imposed position of the external reservoir, namely a position at the end of the shock absorber. Due to this end positioning, these shock absorbers are dependent on the space available at the level of the cycle frame, and prove to be unsuitable and unadaptable to certain cycle frames.

[0005] The invention aims to remedy these problems by proposing a damping system adaptable to any type of cycle frame. SUBJECT OF THE INVENTION

[0006] To this end, and according to a first aspect, the invention proposes a damping system comprising a hollow cylindrical double-walled damper body delimiting an interior volume filled with a damping fluid, a piston assembly comprising a piston rod mounted to slide axially through the damper body and a piston, integral with the piston rod, arranged within the interior volume so as to delimit the latter into a compression chamber and an expansion chamber, the damper body comprising an inner wall and an outer wall, concentric, delimiting between them a circulation corridor for the damping fluid, the inner wall comprising at least a first communication orifice ensuring communication between the circulation corridor and the compression chamber and at least a second communication orifice ensuring communication between the circulation corridor and the expansion chamber,the outer wall comprising an orifice for communication with the circulation corridor. The damping system is remarkable in that the shock absorber body comprises a radial separating partition sealingly connecting the outer and inner walls together and dividing the circulation corridor into two hydraulic channels separate from each other, one of the hydraulic channels communicating with the compression chamber through the first orifice, the other hydraulic channel communicating with the expansion chamber through the second orifice formed in the inner wall, the outer wall comprising at least two radial orifices, one of the radial orifices opening onto the hydraulic channel communicating with the compression chamber, the other orifice opening onto the hydraulic channel communicating with the expansion chamber.

[0007] Thus, thanks to the presence of the separating partition, two hydraulic paths independent of each other, namely a compression path and an expansion path, are created, the outlet orifices of each of these paths being able to be provided at any point of the shock absorber. The position of the reservoir or any other external equipment intended to be coupled to the double-wall shock absorber is thus no longer limited to the sole end position as encountered with the double-wall shock absorbers of the prior art.

[0008] Advantageously, the damping system comprises an annular seal interposed radially between the inner wall and the outer wall, said seal forming the separating partition. This arrangement has the advantage of simplifying the manufacture and assembly of the constituent parts of the shock absorber body.

[0009] Advantageously, the first and / or second communication orifice(s) is (are) arranged to form a radial fluid passage through the internal wall.

[0010] According to a particularly advantageous variant, the internal wall has a series first and second communication orifices distributed axially. The first and second communication orifices are calibrated to have increasingly smaller diameters towards the ends of the shock absorber body. Thanks to the double-wall architecture of the shock absorber body and the separating partition, the first and second communication orifices, thus arranged, form double progressive hydraulic stops, namely in compression and in expansion. When the piston moves in compression, the first communication orifices gradually close, thus increasingly reducing the passage of fluid from the compression chamber to the associated hydraulic path and therefore increasingly increasing the braking. This results in progressive braking of the piston rod in compression.Similarly, when the piston moves in expansion, the second communication orifices gradually close, increasingly reducing the passage of fluid from the expansion chamber to the associated hydraulic channel and therefore increasingly increasing the braking. This results in progressive braking of the piston rod in expansion.

[0011] In order to prevent the suction effect of the piston during compression or expansion, a discharge valve is advantageously provided in the compression and expansion chambers respectively, at each end of the shock absorber body.

[0012] Advantageously, the first and / or second communication orifice(s) is (are) arranged to form an axial fluid passage through the internal wall.

[0013] Advantageously, the damping system comprises a sleeve for connecting a reservoir (or any other equipment) external to the internal volume of the shock absorber body, said connecting sleeve being rotatably mounted on a lateral portion of the external wall of said shock absorber body and arranged to ensure fluid communication between the external reservoir (or other equipment) and each of the hydraulic channels. Thanks to the connecting sleeve, the orientation of the external reservoir (or other equipment) connected to the shock absorber body can be adapted to the cycle on which the damping system is mounted.

[0014] Advantageously, the damping system comprises means for axially locking the connecting sleeve on the damper body.

[0015] Advantageously, the connecting sleeve comprises an annular body for holding on the shock absorber body, provided, on its internal face, with two circumferential grooves, and on its external face, with a radial end piece crossed from one side to the other by two fluid passage channels, each channel opening into one of the grooves.

[0016] According to another aspect, the invention provides a damping system comprising a hollow cylindrical double-walled damper body delimiting an interior volume filled with a damping fluid, a piston assembly comprising a piston rod mounted to slide axially through the damper body and a piston, integral with the piston rod, arranged within the interior volume so as to delimit the latter into a compression chamber and an expansion chamber, the shock absorber body comprising an inner wall and an outer wall, concentric, delimiting between them a circulation corridor for the damping fluid, the inner wall comprising at least a first communication orifice ensuring communication between the circulation corridor and the compression chamber and at least a second communication orifice ensuring communication between the circulation corridor and the expansion chamber, the outer wall comprising a communication orifice with the circulation corridor, the damping system being remarkable in that it comprises a sleeve for connecting a reservoir (or other equipment) external to the internal volume of the shock absorber body,rotatably mounted on a lateral portion of the external wall of said shock absorber body and arranged to provide fluid communication between the external reservoir (or other equipment) and each of the hydraulic channels.

[0017] Other advantageous and non-limiting characteristics of this aspect of the invention may be provided, taken alone or in any technically feasible combination: - the connecting sleeve is free to rotate around its axis. - the connecting sleeve is free to rotate through a 360° rotation degrees around its axis. - the damping system includes means for axially locking the connecting sleeve on the shock absorber body. - the connecting sleeve comprises an annular body for holding on the shock absorber body, provided, on its internal face, with two circumferential grooves, and on its external face, with a radial end piece crossed from one side to the other by two fluid passage channels, each channel opening into one of the grooves. - the shock absorber body comprises a radial separating partition connecting the outer and inner walls together in a sealed manner and dividing the circulation corridor into two hydraulic channels separate from each other, one of the hydraulic channels communicating with the compression chamber through the first orifice, the other hydraulic channel communicating with the expansion chamber through the second orifice formed in the inner wall, the outer wall comprising at least two radial orifices, one of the radial orifices opening onto the hydraulic channel communicating with the compression chamber, the other orifice opening onto the hydraulic channel communicating with the expansion chamber. - the damping system includes an interposed annular seal radially between the inner wall and the outer wall, said joint forming the dividing wall. - the first and / or second communication orifice(s) is (are) arranged to form a radial fluid passage through the internal wall. - the first and / or second communication orifice(s) is (are) arranged to form an axial fluid passage through the internal wall. - the internal wall has a series of first and second communication orifices distributed axially, said first and second communication orifices being calibrated to form double progressive hydraulic stops. - a discharge valve is provided in the compression and expansion chambers, at each end of the shock absorber body. BRIEF DESCRIPTION OF THE FIGURES

[0018] Other characteristics and advantages of the invention will emerge from the detailed description of the invention which follows, given by way of example and with reference to the appended figures in which:

[0019] [Fig.l] [Fig.l] represents a damping system according to a first exemplary embodiment of the invention;

[0020] [Fig.2] [Fig.2] represents a damping system according to a second exemplary embodiment of the invention;

[0021] [Fig.3] [Fig.3] represents the damping system of [Fig.2] provided with a rotating sleeve;

[0022] [Fig.4] [Fig.4] represents a sectional view of the damping system of the [Fig.3] along axis IV-IV;

[0023] [Fig.5] [Fig.5] represents a partial perspective view of the damping system of [Fig.3];

[0024] [Fig.6] [Fig.6] represents a sectional view of the damping system of the [Fig.5] along the VLVI axis;

[0025] [Fig.7] [Fig.7] represents a sectional view of a damping system according to another exemplary embodiment of the invention;

[0026] [Fig.8] [Fig.8] represents a perspective sectional view of the damping system of [Fig.7];

[0027] [Fig.9] [Fig.9] represents a sectional view of a damping system according to another exemplary embodiment of the invention.

[0028] For clarity, identical or similar elements of the different embodiments are identified by identical reference signs throughout the figures. DETAILED DESCRIPTION OF THE INVENTION

[0029] In relation to [Fig.l], a damping system 1 is described comprising, in general, on the one hand a hollow cylindrical damper body 2 delimiting an interior volume 3 filled with a damping fluid, and on the other hand a piston assembly comprising a piston rod 4 mounted to slide axially through the damper body 2 and a piston 5 secured to the piston rod 4. The piston 5 is arranged within the interior volume 3 so as to delimit the latter into a compression chamber 30 and an expansion chamber 31.

[0030] As shown in [Fig.l], the shock absorber body 2 is double-walled. It comprises an inner wall 20 and an outer wall 21, concentric, delimiting between them a circulation corridor 60 for the damping fluid. In the illustrated embodiment, the outer wall 21 surrounds as a whole, i.e. radially and axially, the inner wall 20.

[0031] According to the invention, the shock absorber body 2 comprises a radial separating partition 7 sealingly connecting the internal and external walls 20, 21 to each other, thus dividing the circulation corridor 6 into two hydraulic channels 60, 61 distinct from each other.

[0032] One of the hydraulic channels 60 thus communicates with the compression chamber 30 through orifices 10 while the other hydraulic channel 61 communicates with the expansion chamber 31 through orifices 11 formed in the internal wall 20. In the illustrated embodiment, the orifices 10 and 11 are carried by the internal wall 20 to define axial fluid communications between the chambers and the associated hydraulic channels. In the illustrated example, the internal wall 20 comprises a plurality of orifices 10, 11 communicating respectively with the compression and expansion chambers. It is of course obvious that an internal wall can be provided comprising a single orifice 10 opening into the compression chamber and a single orifice 11 opening into the expansion chamber without departing from the scope of the invention.

[0033] The external wall 21 comprises two series of orifices 12, 13 forming radial fluid openings, one of the series of orifices 12 opening onto the hydraulic channel 60 communicating with the compression chamber 30, the other series of orifices opening onto the hydraulic channel 61 communicating with the expansion chamber 31. The two series of orifices are advantageously located in the vicinity of the separating partition 7, on either side of the latter. Although not shown, the orifices of the two series of orifices 12, 13 are intended to communicate fluidically with an external reservoir or any external hydraulic element connected to the shock absorber body. As for the internal wall 20, it can be provided that the external wall 31 comprises a single orifice 12 opening onto the hydraulic channel 60 and a single orifice 13 opening onto the hydraulic channel 61 without going outside the framework of the invention.

[0034] In the embodiment illustrated in [Fig. 1], the separating partition 7 is formed by a radial rib connecting the inner wall 20 and the outer wall 21 right through and advantageously formed in one piece with both of the inner and outer walls. It is of course obvious that the damping system 1 is not limited to this form of separating partition and that other arrangements can be provided as long as the fluid separation of the circulation corridor is carried out in a sealed manner. The separating partition can thus be formed by an O-ring as in the embodiment illustrated in [Fig. 2] and which will be described later.

[0035] The movement of the fluid during a compression stroke and respectively during the retraction of the piston rod 4 within the shock absorber body is represented by arrows. It is thus represented, during a compression stroke, the circulation of the fluid through the radial orifices 12 of the internal wall 20, then the hydraulic channel 60 to exit through the orifice 12 of the external wall 21, while during the retraction of the piston rod 4, the fluid circulates passes through the orifice 11 of the internal wall 20, then the hydraulic channel 61 to exit through the radial orifice 13 of the external wall 21.

[0036] [Fig. 2] illustrates another example of an embodiment of a damping system IA according to the invention. The system differs from that just described in particular by the arrangement of the double wall and the position of the communication orifices between the chambers 60, 61 and the internal wall 20.

[0037] In this example, the shock absorber body 2 comprises two axially opposite end walls connected to each other by a double lateral wall, namely an internal wall 20 and the external wall 21, delimiting between them a circulation corridor extending axially.

[0038] The internal wall 20 is provided with at least one orifice, in the example illustrated several orifices 10a, 11a, some ensuring communication between the hydraulic channel 60 and the compression chamber 30, the others ensuring communication between the hydraulic channel 61 and the expansion chamber 31. The communication orifices 10a, 11a thus define radial fluid communications between the chambers and the associated hydraulic channels.

[0039] The damping system IA also differs from that illustrated in [Fig.l] by the configuration of the separating partition 7, the latter being formed by an annular seal 7A interposed radially between the inner wall 20 and the outer wall 21. In the example illustrated, the O-ring is held between two radial fins 8, 9 extending between the inner wall 20 and the outer wall 21. Advantageously, the radial fins 8, 9 are carried by the outer wall 21, and are integral with the outer wall 21. The presence of fins 8, 9 has the advantage of ensuring a axial locking of the seal.

[0040] According to a particularly advantageous configuration, the damping system according to the invention comprises a connecting sleeve 14 allowing the connection of an external reservoir (not shown) to the internal volume 3 of the damper body 2, namely the expansion chamber 31 and the compression chamber 30. Such a connecting sleeve 14 is illustrated mounted on the damper body 2 of the damping system 1A of [Fig. 2]. It is of course obvious that the connecting sleeve 14 is not limited to this configuration of the damper body 2, and that it can be implemented on the damper body 2 of the damping system 1 of [Fig. 1] as well as with any other damping system according to the invention (such as for example that illustrated in Figures 7 and 8). It can also be used with a damping system not comprising a separating partition such as the damping system 100 illustrated by way of example in [Fig. 7].

[0041] The connecting sleeve 14, arranged to ensure fluid communication between the external reservoir and the compression and expansion chambers 31 via the hydraulic channels 60, 61, is mounted on the lateral external wall 21 of said shock absorber body 2. It is mounted free to rotate around the external wall 21 following a rotational movement of 360 degrees. The presence of the sleeve thus makes it possible to choose the angular position of the external reservoir or of the external hydraulic element connected to the shock absorber body manually, while making it possible to adapt the handling of the external element to the user (left-handed or right-handed) and to his environment (space, available volume, interaction, etc.).

[0042] As illustrated in Figures 3 to 6, the connecting sleeve 14 comprises an annular holding body 15 on the shock absorber body 2, extended by a radial connection end piece 16 to which the external reservoir is intended to be connected. The holding body 15 is provided, on its internal face, with two circumferential grooves 15a, 15b. The radial end piece 16 is traversed right through by two fluid passage channels 16a, 16b, each channel opening respectively into one of the grooves.

[0043] Advantageously, the damping system IA comprises means for axially locking the connection sleeve 14 on the damper body 2, in order to prevent the sleeve from moving along the damper body 2 as well as a possible break in the fluid connection between the external reservoir and the compression and expansion chambers 30, 31 of the damper body 2.

[0044] Thanks to the connecting sleeve, the orientation of the external reservoir can be adapted to the frame of the cycle on which the damping system is mounted.

[0045] Figures 7 and 8 illustrate another example of an embodiment of a damping system IB according to the invention. This uses the arrangement of the double wall of the embodiment of the system 1 of [Fig.l]. It differs therefrom, however, in that the internal wall 20 is provided on the one hand with orifices 10, 11 defining axial fluid communications between the chambers and the hydraulic passages and on the other hand with orifices 10a, 11a, defining radial fluid communications between the chambers and the associated hydraulic passages. The system 1B further comprises compensation (or unloading) valves 18, 19, of annular shape in the illustrated example, arranged in the compression and expansion chambers, at each end of the shock absorber body, opposite the axial orifices 10, 11. In the illustrated example, the compensation valve 18 arranged in the compression chamber is shown closed while the compensation valve 19 arranged in the expansion chamber is shown open. This state is obtained just after reaching the hydraulic expansion stops, ieat the start of the compression phase. The compensation valve 18 will open while the compensation valve 19 will close at the very start of the expansion phase, just after reaching the hydraulic compression stops.

[0046] [Fig. 9] illustrates a damping system 100 comprising a single hydraulic channel (double-walled damping body without a separating partition). In this example, the holding body 15 of the connecting sleeve 14 is provided, on its internal face, with a single circumferential groove, the radial end piece being traversed from one side to the other by a single fluid passage channel opening into the groove. As in the example previously described, the connecting sleeve 14A is mounted to rotate freely around the lateral external wall 21 of the damping body following a rotational movement of 360 degrees. Similarly, as previously, means for axially locking the connecting sleeve 14 on the damper body 2 may advantageously be provided, in order to prevent the sleeve from moving along the damper body 2.

[0047] The invention is described in the above by way of example. It is understood that a person skilled in the art is able to carry out different variant embodiments of the invention without departing from the scope of the invention.

Claims

Claims

1. Damping system (1, IA, IB) comprising: - a hollow cylindrical double-walled shock absorber body (2) delimiting an interior volume (3) filled with a damping fluid, - a piston assembly comprising a piston rod (4) mounted to slide axially through the shock absorber body (2) and a piston (5), integral with the piston rod (4), arranged within the interior volume (3) so as to delimit the latter into a compression chamber (30) and an expansion chamber (31), - the shock absorber body (2) comprising an inner wall (20) and an outer wall (21), concentric, delimiting between them a circulation corridor for the damping fluid, the inner wall (20) comprising at least a first communication orifice ensuring communication between the circulation corridor and the compression chamber (30) and at least a second communication orifice ensuring communication between the circulation corridor and the expansion chamber (31), the outer wall (21) comprising a communication orifice with the circulation corridor, characterized in that the shock absorber body (2) comprises a radial separating partition (7) sealingly connecting the external and internal walls together and dividing the circulation corridor into two hydraulic channels distinct from each other, one of the hydraulic channels communicating with the compression chamber (30) through the first orifice, the other hydraulic channel communicating with the expansion chamber (31) through the second orifice formed in the internal wall (20), the external wall (21) comprising at least two radial orifices, one of the radial orifices opening onto the hydraulic channel communicating with the compression chamber (30), the other orifice opening onto the hydraulic channel communicating with the expansion chamber (31).

2. Damping system (1, IA, IB) according to claim 1, characterized in that it comprises an annular seal interposed radially between the inner wall (20) and the outer wall (21), said seal forming the separating partition (7).

3. Damping system (1, IA, IB) according to claim 1 or claim 2, characterized in that the first and / or second communication orifice(s) is (are) arranged to form a radial fluid passage through the internal wall (20).

4. Damping system (1, IA, IB) according to any one of claims 1 to 3, characterized in that the internal wall (20) has a series of first and second communication orifices distributed axially, said first and second communication orifices being calibrated to form double progressive hydraulic stops.

5. Damping system (1, IA, IB) according to any one of claims 1 to 4, characterized in that a discharge valve is provided in the compression and expansion chambers, at each of the ends of the shock absorber body.

6. Damping system (1, IA, IB) according to any one of the preceding claims, characterized in that the first and / or second communication orifice(s) is (are) arranged to form an axial fluid passage through the internal wall (20).

7. Damping system (1, IA, IB) according to any one of the preceding claims, characterized in that it comprises a connecting sleeve (14) of a reservoir or any other equipment external to the internal volume of the shock absorber body (2), said connecting sleeve (14) being rotatably mounted on a lateral portion of the external wall (21) of said shock absorber body (2) and arranged to ensure fluid communication between the reservoir or any other or external equipment and each of the hydraulic channels.

8. Damping system (1, IA, IB) according to the preceding claim, characterized in that it comprises means for axially locking the connecting sleeve (14) on the shock absorber body (2).

9. Damping system (1, IA, IB) according to claim 7 or claim 8, characterized in that the connecting sleeve (14) comprises an annular body for holding on the shock absorber body (2), provided, on its internal face, with two circumferential grooves, and on its external face, with a radial end piece crossed from one side to the other by two fluid passage channels, each channel opening into one of the grooves.

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