Device for volume compensation of damping fluid for a damper

Abstract

The present invention relates to a device for volume compensation of a damping liquid for a damper, which device is capable of reducing the static pressure of the damper to ensure the pressure of a chamber called the negative chamber and serves as a filter for vibrations. The device comprises a hollow cylindrical body (1) containing a damping fluid, at least one of the ends of which is provided with an axial passage for the passage, sealing and guiding of a rod (2), which rod is fixed to the main piston (3), which main piston moves translationally inside the body and divides it into two different working chambers, one working chamber constituting the compression chamber (4) and the other working chamber constituting the expansion chamber (5).

Description

Technical Field

[0001] The present invention relates to the field of dampers present in the suspensions of vehicles, in particular motor vehicles, motorcycles, bicycles and the like.

[0002] The present invention more particularly relates to a device that can compensate for variations in the oil volume (or the volume of any other fluid used) inside a damper, whether this is due to thermal expansion or to the displacement of the piston rod. Background Art

[0003] In a simplified manner, a damper includes at least one hollow cylindrical body containing a damping fluid (such as oil), at least one of whose ends is provided with an axial passage for the passage, sealing and guiding of a rod (which serves to transmit an external force), the rod being fastened to a main piston (which serves to transmit the force generated by internal load losses to the rod), the main piston moving translationally inside the body and dividing it into two different working chambers, one working chamber constituting the compression chamber and the other working chamber constituting the expansion chamber. An energy dissipation device (oil laminate) is directly present inside the main piston or projects outside the body and thus includes an additional hydraulic circuit that allows the oil to circulate between the compression chamber and the expansion chamber. During operation, the internal volume available for the oil varies greatly for two main reasons; on the one hand, the thermal expansion of the oil, which is different from the thermal expansion of the materials of the body and the other components constituting the damper; and on the other hand, the translation of the volume of the rod, which is located locally inside the body during the compression phase and then outside the body during the expansion phase.

[0004] In order to compensate for variations in the oil volume inside a damper, the current state of the art includes a chamber known as a compensation chamber. The compensation chamber is a compressible volume (such as a cylinder containing a gas) of oil (i.e., oil subjected to pressure variations) connected to the main circuit of the damper, which includes a separating device (such as a floating piston or a membrane) between the oil and the compressible or in-compressible element. The compensation chamber can have an initial zero or non-zero static pressure, or be referred to as "open" and thus have a pressure known as constant atmospheric pressure.

[0005] The first solution mainly lies in connecting the compensation chamber to the compression chamber (or, correspondingly, the expansion chamber). In this case, the compensation chamber must have a static pressure (the initial pressure not due to piston movement) greater than the maximum dynamic pressure (the pressure generated due to piston movement) in the compression chamber (or, correspondingly, the expansion chamber). Otherwise, the displacement of the piston will result in the compression of the compensation chamber, rather than the displacement of the oil through the energy dissipation device, that is, a "spring" - type behavior contrary to the sought - after "damper" type. The required increased static pressure for operating this solution leads to the following phenomena: the restoring force of the damper rod, which can typically reach 300 N (an example of a rear damper of a mountain bike); the increased threshold for joint movement (referred to as "stiction"); and an increased risk of leakage. These phenomena will directly cause deterioration in performance in terms of comfort (referred to as damper sensitivity), adhesion, and reliability.

[0006] The second solution mainly lies in connecting the compensation chamber after the energy dissipation device. Thus, the pressure loss generated by the device can reduce the maximum dynamic pressure experienced by the compensation chamber and can correspondingly reduce its required static pressure. The second solution does not completely suppress the static pressure but reduces it by about three times. However, this involves the use of a remote energy dissipation device.

[0007] In addition, apart from the problem of increased static pressure, the existing problem is that it is impossible to immediately ensure what is called a negative volume change in the compensation chamber. During compression (or, correspondingly, expansion), the pressure in the compression chamber (or, correspondingly, the expansion chamber) increases; thus, it is called "positive", while the expansion chamber (or, correspondingly, the compression chamber) is called "negative". If the compensation chamber is not directly connected (i.e., has a low or negligible pressure loss) to the negative chamber, volume compensation cannot be achieved sufficiently quickly, which can lead to a low pressure in the negative chamber (i.e., a pressure lower than the static pressure of the damper). The low pressure can cause boiling and / or vacuum and lead to cavitation, which damages functional components and reduces performance.

[0008] Finally, these solutions do not allow for sufficient management of the vibrations re - transmitted by the rod. If the role of the damper is to effectively damp the movement of the rod (by dissipating energy), ideally, the damper should also allow for filtering its vibrations, that is, not re - transmitting them to the body (via the energy dissipation device). To achieve this, ideally, the volume change generated by the vibrations should be immediately and directly compensated by the compensation chamber. However, in the configurations of the above two solutions, this is not possible because the static pressure of the compensation chamber is too high (greater than the over - pressure generated by the vibrations), or because the compensation chamber is positioned "behind" the energy dissipation device. Not filtering the vibrations leads to limitations in comfort and adhesion performance and causes heating of the oil, thus deteriorating the operational reliability of the damper. Summary of the Invention

[0009] The device according to the invention can connect (or, respectively, disconnect) the compensation chamber directly (i.e., with a low or negligible pressure loss) to the negative (or, respectively, positive) chamber each time the direction of movement of the piston changes, i.e., for each passage from the compression phase to the expansion phase and vice versa (the said passage from one phase to the other is called the transition phase). Thus, the compensation chamber never undergoes a dynamic overpressure (which only exists in the positive chamber), and its static pressure can be chosen to be as low as possible, thereby ensuring optimal functionality (comfort, adhesion, and reliability) without a triggering threshold, without an adhesive connection of the seal, and without a risk of leakage.

[0010] Furthermore, the direct connection (low or negligible pressure loss) can ensure the minimum pressure in the negative chamber, and thus, this pressure is equal to the static pressure of the compensation chamber, which reduces the risk of cavitation.

[0011] Finally, the device according to the invention allows for a direct connection (i.e., with a low or negligible pressure loss) between the compression chamber, the expansion chamber, and the compensation chamber during a phase change (i.e., during a change in the direction of the piston). Thus, during the said short transition phase, the oil is exchanged only between the above three chambers and in a manner with a low or negligible pressure loss. In this range of use, regardless of whether it is in compression or in expansion, and regardless of the passage speed from one phase to the other, these movements of the piston (referred to as low-amplitude oscillations or vibrations) are thereby filtered out. Thus, neither energy dissipation nor force transmission to the body occurs. Therefore, the performance in terms of comfort, adhesion, and reliability (without heating the engine oil) is significantly improved.

[0012] To achieve this, the device according to the invention comprises at least one hollow cylindrical body containing a damping fluid (such as oil), at least one of its ends being provided with an axial channel for the passage, sealing, and guiding of a rod, which is fastened to a main piston that moves translationally within the body and divides it into two different working chambers, one working chamber constituting the compression chamber and the other working chamber constituting the expansion chamber. The energy dissipation means (oil laminate) is directly present inside the main piston or projects outside the body and thus includes a hydraulic circuit that allows the oil to circulate between the compression chamber and the expansion chamber.

[0013] According to the first feature, the device includes a compensation chamber which is directly connected (i.e., with low or negligible pressure loss) to the compression chamber and the expansion chamber via one or more internal channels located in the rod and / or in the piston and thus one or more orifices leading to the compression chamber and to the expansion chamber in the area of the rod and / or the piston. These orifices are called compensation orifices. Thus, according to an advantageous embodiment, the compensation chamber will be fastened to the rod which is positioned opposite the piston and outside the body. However, the compensation chamber can be positioned anywhere and any type of connection can be used according to common practice, which makes it possible to achieve the above - mentioned specific features.

[0014] According to the second feature, the device includes one or more rigid components called sliders (in the rest of this specification and for the sake of simplicity, will be referred to as "slider", whether it is single or multiple), which can freely translate axially along the rod (and the body), around the piston and / or the rod or within the piston and / or the rod, and between two end positions, one towards the compression chamber called the "expansion position" and the other towards the expansion chamber called the "compression position". In its expansion position (or, correspondingly, compression position), the said slider closes (or actuates the means for closing) the compensation orifice of the expansion chamber (or correspondingly, the compression chamber) and releases (or actuates the means for releasing) the compensation orifice of the compression chamber (or, correspondingly, the expansion chamber). Since the compensation orifices and the slider are positioned in such a way that it is not possible to close both the compensation orifice of the compression chamber and the compensation orifice of the expansion chamber simultaneously, and the sum of the free cross - sections of these orifices (i.e., those not closed by the slider) always allows the direct passage of oil (i.e., with lower or negligible pressure loss). Since the slider is a rigid component, completely closing the compensation orifice of the compression chamber (or, correspondingly, the expansion chamber) necessarily and immediately causes the opening of the compensation orifice of the expansion chamber (or, correspondingly, the compression chamber). According to an advantageous embodiment, the slider and the piston and / or the rod can be of complementary shapes which allow the orifices to be closed in a progressive manner and allow the orifices to be completely closed before any physical contact between different components.

[0015] Thus, since the slider is freely translatable, when the damper starts the compression phase (or, correspondingly, the expansion phase), the increase in pressure (dynamic pressure) in the compression chamber (or, correspondingly, the expansion chamber) generates a force which will move the slider towards its compression position (or, correspondingly, the expansion position), thus closing the compensation orifice of the compression chamber (or, correspondingly, the expansion chamber) and opening the compensation orifice of the expansion chamber (or, correspondingly, the compression chamber). Thus, the compensation chamber will be directly connected to the expansion chamber (or, correspondingly, the compression chamber), i.e., the chamber called negative, but will have no connection with the compression chamber (or, correspondingly, the expansion chamber) (i.e., the chamber called positive).

[0016] According to the third feature, if another solution is implemented for managing the variation of the oil volume, or if such management is unnecessary and thus there is no compensation chamber directly connected to the rod and / or the main piston, the piston includes one or more channels allowing a direct connection between the compression chamber and the expansion chamber, which can ensure the above-mentioned vibration filtering function.

[0017] According to a particular embodiment, the slider is in contact with the body in the radial direction. Thus, the friction existing between the slider and the body (however small this frictional force may be) hinders the movement of the slider. Therefore, when the piston moves towards the compression chamber (or, correspondingly, the expansion chamber), even before the pressure in the compression chamber (or, correspondingly, the expansion chamber) increases significantly, the slider resisting the movement moves relative to the piston towards the expansion chamber (or, correspondingly, the compression chamber). Thus, this phenomenon accelerates the positioning of the slider and thus shortens the duration of the transition phase.

[0018] According to a particular embodiment, the slider is located outside the piston, i.e., it does not pass through the piston. Thus, it is impossible for the piston to be in direct radial contact with the body; the slider necessarily exists between the two components. This embodiment leads to a simplification of the main piston while ensuring the above-mentioned particular embodiment.

[0019] According to a particular embodiment, the compensation orifice exists only on the piston. This embodiment leads to a simplification of the form of the rod and the slider.

[0020] According to a particular embodiment, the slider and the piston are integral. Thus, the "piston / slider" translates directly on the rod including the compensation orifice. This embodiment leads to a reduction in the number of components.

[0021] According to a particular embodiment, the slider passes through the piston with a discontinuous cross-section (e.g., cylindrical). This embodiment leads to the isolation of the instantaneous forces between the slider and the rod, the piston, and the body (radially), and thus ensures that the translation of the device has an optimized quality, thereby ensuring responsiveness.

[0022] According to a particular embodiment, the slider closes an oil volume that decreases as the slider approaches its end position. The shape of the slider is such that, corresponding to its end position, the volume is closed before the "solid" interaction of the slider with the piston and / or the rod. The confinement of this volume creates a hydraulic stop. The oil volume is connected to a hydraulic circuit that is connected to the negative chamber and includes a check-type device (valve, ball / spring, specific fitting, etc.), and the check-type device can resupply the oil volume during the phase change and move the slider again. This type of behavior of the progressive hydraulic stop can eliminate any risk of impact, noise, or vibration associated with reaching the end position of the slider; the operation of the device is softer and quieter.

[0023] Thus, according to the first embodiment, the present invention relates to a device for volume compensation of damping liquid for a damper, in particular for a suspension assembly of a bicycle and other vehicles, the device comprising at least one hollow cylindrical body containing a fluid, at least one of the ends of the body being provided with an axial channel for the passage, sealing and guiding of a rod, the rod being fastened to a main piston, the main piston being translatable inside the body and dividing it into two different working chambers, one working chamber constituting a compression chamber and the other working chamber constituting an expansion chamber, characterized in that the device comprises:

[0024] - On the one hand, a compensation chamber, the compensation chamber being directly connected (i.e., with very small or negligible pressure losses) to the compression chamber and the expansion chamber via one or more internal channels located in one or both of the rod and the piston and thus via one or more orifices (referred to as compensation orifices) leading to the compression chamber and to the expansion chamber in the region of the rod and / or the piston,

[0025] - And, on the other hand, one or more rigid members, referred to as sliders, the sliders being able to translate freely along the axial direction of the rod (2) and the axial direction of the body, around the piston and / or the rod, or inside the piston and / or the rod, and between two end positions, one end position being towards the compensation chamber (correspondingly, the other end position being towards the expansion chamber) referred to as the "expansion position", wherein the slider closes (or actuates the device for closing) the compensation orifice of the expansion chamber (5) (or, correspondingly, the compression chamber) and releases (or actuates the device for releasing) the compensation orifice of the compression chamber (or, correspondingly, the expansion chamber), the compensation orifices and the sliders being positioned such that it is not possible to close both the compensation orifice of the compression chamber and the compensation orifice of the expansion chamber simultaneously, and the sum of the free cross-sections (i.e., not closed by the slider) of the compensation orifices still allowing for the direct passage of oil (i.e., with small or negligible pressure losses).

[0026] According to another embodiment, the present invention also relates to a device for volume compensation of damping liquid for a damper, in particular for a suspension assembly of a bicycle and other vehicles, the device comprising at least one hollow cylindrical body containing a fluid, at least one of its ends being provided with an axial channel for the passage, sealing and guiding of a rod, the rod being fastened to a main piston, the main piston being translatable inside the body and dividing it into two different working chambers, one working chamber constituting a compression chamber and the other working chamber constituting an expansion chamber, characterized in that the device comprises:

[0027] - On the one hand, the compensation chamber and the expansion chamber are directly connected to each other (i.e., having a small or negligible pressure loss) or via one or more internal channels located in the rod and / or the piston, and thus connected to each other via one or more orifices leading to the compression chamber and to the expansion chamber in the region of the rod and / or the piston,

[0028] - And, on the other hand, one or more rigid members called sliders, which can freely translate axially along the rod and the axial direction of the body, around the piston and / or the rod, or within the piston and / or the rod, and between two end positions, one end position facing the compensation chamber called the "expansion position" (correspondingly, the other end position facing the expansion chamber called the "compression position"), wherein the slider closes (or actuates the means for closing) the orifice of the expansion chamber (or, correspondingly, the compression chamber), and releases (or actuates the means for releasing) the orifice of the compression chamber (or, correspondingly, the expansion chamber), the orifices and the slider are positioned such that it is impossible to simultaneously close the compensation orifice of the compression chamber and the compensation orifice of the expansion chamber, and the sum of the free cross-sections of the compensation orifices (i.e., not closed by the slider) still allows the direct passage of oil (i.e., having a small or negligible pressure loss).

[0029] Other advantageous and non-limiting features according to these two embodiments are obtained individually or in any technically possible combination:

[0030] - The slider contacts the body in the radial direction.

[0031] - On the one hand, the slider is locally positioned between the piston and the body, and on the other hand, the compensation orifices are only present on the piston.

[0032] - The slider and the piston form a single piece, i.e., the piston / slider translates around the rod.

[0033] - The slider passes through the piston with a non-continuous cross-section (e.g., cylindrical).

[0034] - The slider closes the oil volume on the compression side (or, correspondingly, the expansion side during the expansion phase) during the compression phase, and this volume decreases as the slider approaches its end position. The shape of the slider is such that the volume becomes closed before the "solid" interaction between the slider and the piston and / or the rod. The oil volume is connected to the expansion chamber (or, correspondingly, the compression chamber) via a hydraulic circuit, and the hydraulic circuit also includes a check-type device that only allows oil to move from the expansion chamber (or, correspondingly, the compression chamber) towards the volume.

[0035] - The slider and the piston and / or the rod have complementary shapes that allow the orifices to be closed in a progressive manner and to be completely closed before any solid contact between different components.

[0036] - The compensation chamber is fixed to the rod and is positioned opposite the piston and outside the body.

[0037] - The slider is arranged to freely translate through a passage formed in the region of the piston, which passage is different from the internal passage.

[0038] According to another embodiment, the present invention also relates to a device for volume compensation of a damping liquid for a damper, in particular for a suspension assembly of a bicycle and other vehicles, the device comprising

[0039] - At least one hollow cylindrical body that contains fluid and has at least one end provided with an axial passage for the passage, sealing and guiding of the rod, the rod being fastened to a main piston that translates within the body and divides it into two different working chambers, one working chamber constituting a compression chamber and the other working chamber constituting an expansion chamber, the compression chamber and the expansion chamber being directly connected to each other via one or more internal passages for the fluid to pass through the piston and via one or more compensation orifices leading to the compression chamber and to the expansion chamber in the region of the piston, and via a shut-off valve for the compensation orifices leading to the compression chamber and to the expansion chamber.

[0040] - At least one rigid member that is inserted between the shut-off valves leading to the compression chamber and to the expansion chamber, the rigid member being capable of translating in the axial direction of the rod and in the axial direction of the body between a first end position and a second end position, in the first end position, the compensation orifice leading to the expansion chamber is closed by the dedicated valve, while the compensation orifice leading to the compression chamber is not closed by the dedicated valve, in the second end position, which is called the compression position, the compensation orifice leading to the compression chamber is closed by the dedicated valve, while the compensation orifice leading to the expansion chamber is not closed by the dedicated valve, the compensation orifices and the rigid member being positioned such that it is not possible to simultaneously close both the compensation orifice leading to the compression chamber and the compensation orifice leading to the expansion chamber, and such that the sum of the cross-sectional areas of the compensation orifices not closed by the unactuated rigid member still allows oil to pass directly through.

[0041] The remarkable feature of the present invention is that the rigid member is arranged to freely translate through a passage formed in the region of the piston, which passage is different from the internal passage.

[0042] According to other advantageous and non-limiting features of the present invention, obtained individually or in any technically possible combination:

[0043] - The shut-off valve includes two flexible plates fixed on either side of the piston and fastened to the piston, the plates being able to move from a closed position to an open position, in which closed position the plates are arranged to rest against the piston so as to close the compensation orifice, and in which open position the plates are moved away from the piston under the thrust of a rigid member, thereby releasing the compensation orifice.

[0044] - The rigid member includes a pin that translates through a passage in the piston.

[0045] - The shut-off valve is arranged at the end of the piston, and the shut-off valve and the rigid member form a single piece.

[0046] - The passage for the translation of the rigid member is formed between the piston and the piston body.

[0047] - The rigid member contacts the body in the radial direction.

[0048] - The rigid member passes through the piston with a non-continuous cross-section (e.g., cylindrical).

[0049] - The rigid member closes the oil volume on the compression side (or, correspondingly, the expansion side during the expansion phase) during the compression phase, the oil volume decreasing as the rigid member approaches its end position, the shape of the rigid member being such that the volume is closed before the "solid" interaction between the rigid member and the piston, the oil volume being connected via a hydraulic circuit to the expansion chamber (or, correspondingly, the compression chamber), the hydraulic circuit also including a check-type device that allows oil to move only from the expansion chamber (or, correspondingly, the compression chamber) towards the volume.

[0050] - The rigid member and the piston have complementary shapes that allow the orifice to be closed in a progressive manner and to be fully closed before any solid contact between the different components.

[0051] - The device includes a compensation chamber that is directly connected (i.e., with low or negligible pressure losses) to the compression chamber and the expansion chamber.

[0052] - The compensation chamber is connected to the compression chamber and the expansion chamber via an axial internal passage of the rod, the axial internal passage being fluidly connected to the internal passage of the piston.

[0053] - The compensation chamber is fastened to the rod and is positioned opposite the piston and outside the body. Description of the Drawings

[0054] This drawing illustrates the present invention:

[0055] Figure 1 and Figure 2 is a simplified schematic view in longitudinal section of a damper intended for use during the compression phase ( Figure 1) and expansion phase ( Figure 2 ) during the positioning of the main components and detailing the locations of the chambers known as positive and negative;

[0056] Figure 3 is a simplified schematic diagram of the main elements of a damper equipped with an internal compensation chamber in longitudinal section;

[0057] Figure 4 is a simplified schematic diagram of the main elements of a damper equipped with an external compensation chamber in longitudinal section;

[0058] Figure 5 is a simplified schematic diagram of a first embodiment of the present invention in longitudinal section;

[0059] Figure 6 、 Figure 7 、 Figure 8 and Figure 9 is a simplified schematic diagram of the first embodiment of the slider in longitudinal section, detailing the fluid in the compression phase ( Figure 7 ), expansion phase ( Figure 9 ) and the transition phase ( Figure 6 and Figure 8 ) during the hydraulic path taken;

[0060] Figure 10 is a simplified schematic diagram of a variant of the invention in longitudinal section, in which the volume of the rod in the damper is unchanged;

[0061] Figure 11 and Figure 12 The second embodiment of the slider is in the compression stage ( Figure 11 ) and expansion phase ( Figure 12 ) during a simplified schematic diagram in longitudinal section;

[0062] Figure 13 is a simplified schematic illustration of a third embodiment of the slider (in this case, in the position during the expansion phase) in longitudinal section;

[0063] Figure 14 、 Figure 15 、 Figure 16 and Figure 17 The third embodiment of the slider is in the compression stage ( Figure 15 ), expansion stage ( Figure 17 ) and the transition phase ( Figure 14 and Figure 16 ) during a simplified schematic diagram in longitudinal section;

[0064] Figure 18 、 Figure 19 、 Figure 20 and Figure 21is a perspective view of the rod / piston assembly according to the fourth embodiment ( Figure 18 ), and simplified perspective views in longitudinal section during the compression phase ( Figure 19 ) and the expansion phase ( Figure 20 ).

[0065] For the sake of clarity, the same or similar elements (i.e., elements with the same function) in different figures are denoted by the same reference numerals in all figures. Detailed Description of the Invention

[0066] Figure 1 、 Figure 2 、 Figure 3 and Figure 4 are two-dimensional schematic views showing the damper in a simplified cross-section in order to define and name the various elements common in the damper, and their functions have been described above. Throughout the text, these elements are provided with capital letters in order to indicate that they are precisely defined. All these elements are referenced in the drawings.

[0067] For all the drawings, the double arrow indicates the direction of movement of the rod 2 and thus the direction of movement of the piston 3 connected thereto.

[0068] For all the drawings, (-) indicates low pressure, i.e., a pressure less than or equal to the static pressure of the damper. It should be remembered that the static pressure of the damper is the initial pressure in the absence of movement of the rod 2.

[0069] For all the drawings, (+) indicates overpressure, i.e., a pressure greater than or equal to the static pressure of the damper.

[0070] Figure 1 、 Figure 2 、 Figure 3 and Figure 4 and all other drawings show the above elements, such as the body 1 containing the damping fluid, the rod 2 (whose function is to retransmit the external force), the piston 3 or the main piston (whose function is to transmit the force generated by the internal pressure loss to the rod), the compression chamber 4 (whose pressure increases during the compression phase and decreases during the expansion phase), the expansion chamber 5 (whose pressure increases during the expansion phase and decreases during the compression phase), the energy dissipation device 6, the hydraulic circuit 7 allowing the oil to circulate between the compression chamber and the expansion chamber, the compensation chamber 8 capable of compensating for the change in the oil volume inside the damper, and the separation device between the oil and the compressible element of the compensation chamber, which is called the floating piston 9, for the sake of simplicity, even if there are other systems (membranes, etc.).

[0071] Figure 3 A damper is specifically shown in which the compensation chamber 8 is directly connected to the compression chamber. The disadvantages of this solution have been described above.

[0072] Figure 4A damper is particularly shown, whose compensation chamber 8 is connected "behind" the energy dissipation device 6, and its advantages and limitations have been described above.

[0073] Figure 5 is a two-dimensional schematic view showing an embodiment of a damper that meets all the requirements of the invention.

[0074] To achieve this, the device according to the invention comprises at least one hollow cylindrical body 1 containing a damping fluid, at least one of the ends of the body being provided with an axial channel for the passage, sealing and guiding of a rod 2, which rod is fastened to a main piston that moves translationally inside the body 1 and divides it into two different working chambers, one working chamber constituting a compression chamber 4 and the other working chamber constituting an expansion chamber 5. The energy dissipation device 6 projects outside the body 1 and thus comprises a hydraulic circuit 7 that allows oil to circulate between the compression chamber and the expansion chamber.

[0075] According to this embodiment, the device comprises: a compensation chamber 8 that is directly connected to the compression chamber 4 and the expansion chamber 5 via an internal channel 10 located in the rod 2 and / or in the piston 3 and thus via one or more compensation orifices 11 that lead to the compression chamber 4 and to the expansion chamber 5 in the region of the piston 3. The slider 12 is a first embodiment, the operation of which is detailed in Figure 6 、 Figure 7 、 Figure 8 and Figure 9 In this case, the slider 12 is a single piece that moves translationally freely around the piston 3. In this embodiment, the slider 12 is formed by a rigid part that forms a sleeve arranged between the body 1 and the piston 3, and the parts forming the sleeve have lower flanges at each end, which lower flanges form shut-off valves for the compensation orifices 11. Thus, in this embodiment, the shut-off valves form a single piece with the rigid part that forms the sleeve.

[0076] In Figure 6 、 Figure 7 、 Figure 8 and Figure 9 the dashed arrows indicate the path and the direction of displacement of the oil.

[0077] Figure 6Corresponding to the start of the compression phase, i.e., the instantaneous compression phase. The rod 2 moves towards the compression chamber (on the right side in this example). The pressure in the compression chamber increases, which causes the oil to shift from the compression chamber towards the expansion chamber through the compensation orifice 11 and the internal passage 10. Thus, the oil does not pass through the energy dissipation device (external in this case); there is no energy loss, no damping, and thus no reaction force against the displacement of the rod 2. Therefore, the filtering phenomenon occurs. During the compression phase, the rod 2 enters the body. Therefore, the oil volume replaced by the volume of the entering rod 2 must leave the body because there is an "incompressible" fluid. Thus, as shown by the dashed arrow, the said oil volume travels from the compression chamber towards the compensation chamber via the internal passage 10.

[0078] Figure 7 Corresponding to the "actual" compression phase, i.e., immediately following the closing of the compensation orifice 11 by the slider 12 on the compression side. With the closing of the compensation orifice 11, the oil cannot directly re-enter the expansion chamber but is forced to move towards the external energy dissipation device. Thus, energy dissipation occurs. Thereby, the damping phenomenon appears. Since there is a piston rod 2 in the expansion chamber, the volume of oil displaced by the movement of the piston 3 towards the compression chamber is larger than the volume of oil available in the expansion chamber. Then, the excess oil returns to the compensation chamber via the compensation orifice 11 and the internal passage 10 opening on the expansion side.

[0079] Figure 8 Corresponding to the start of the expansion phase, i.e., the instantaneous expansion phase. The rod 2 moves towards the expansion chamber (to the left in this case). The pressure in the expansion chamber increases, which causes the oil to shift from the expansion chamber towards the compression chamber through the compensation orifice 11 and the internal passage 10. Thus, the oil does not pass through the energy dissipation device; there is no energy loss, no damping, and thus no reaction force against the displacement of the rod 2. Therefore, the filtering phenomenon occurs. During the expansion phase, the rod 2 leaves the body. Therefore, the oil volume released by the volume of the rod 2 must be compensated. Thus, as shown by the dashed arrow, the said oil volume travels from the compensation chamber towards the compression chamber via the internal passage 10.

[0080] Figure 9 Corresponding to the "actual" expansion phase, i.e., immediately following the closing of the compensation orifice 11 by the slider 12 on the expansion side. With the closing of the compensation orifice 11, the oil cannot directly re-enter the compression chamber but is forced to move towards the external energy dissipation device. Thus, energy dissipation occurs. Thereby, the damping phenomenon appears. Since there is a rod 2 in the expansion chamber, the volume of oil displaced by the movement of the piston 3 towards the expansion chamber is smaller than the volume of oil available in the compression chamber. Therefore, the said oil volume is compensated by the displacement of oil from the compensation chamber towards the compression chamber via the compensation orifice 11 and the internal passage 10 opening on the compression side.

[0081] Figure 10Shows an embodiment of the invention without a compensation chamber. In this example, the rod 2 is "continuous". Thus, its movement does not cause any change in the available volume of the oil. In this case, the invention can be used for the sole purpose of achieving the above-described filtering phenomenon. In this case, the same type of slider 12 as described above is used to implement the solution. Its advantage lies in its simple shape and in contacting the body, by virtue of the friction it has, it is naturally and quickly positioned in the correct position to allow the closing and releasing of the compensation orifice 11.

[0082] Figure 11 and Figure 12 Shows a second embodiment of the slider 12. In this case, the slider 12 and the piston 3 form a single piece. Thus, the "piston 3 / slider 12" translates directly on the rod 2. This embodiment results in a reduction in the number of components.

[0083] Figure 11 Shows this embodiment during the compression phase. It should be noted here that the compensation chamber (not visible in the figure) is connected only to the expansion chamber (to the left) via the internal channel 10.

[0084] Figure 12 Shows this embodiment during the expansion phase. It should be noted here that the compensation chamber (not visible in the figure) is connected only to the compression chamber (to the right) via the internal channel 10.

[0085] Figure 13 Shows a third embodiment of the slider 12. In this case, the slider 12 passes through the piston 3 with a non-discontinuous cross-section (such as cylindrical). This embodiment results in the isolation of the instantaneous forces between the slider 12, the rod 2, the piston 3, and the body (not shown in the figure), and thus ensures an optimized quality and responsiveness of the translation of the device.

[0086] Figure 14 、 Figure 15 、 Figure 16 and Figure 17 Shows this type of "continuous" slider at the beginning of compression ( Figure 14 ), during the compression phase ( Figure 15 ), at the beginning of expansion ( Figure 16 ), and during the expansion phase ( Figure 17Particular embodiments during the period. At the beginning of the expansion phase, the slider 12 closes the oil volume 16 which decreases as the slider approaches its end position (closing the compensation orifice 11). Arrow 15 indicates the direction of movement of the slider 12. The shape of the slider is such that the volume 16 closes before the "physical" interaction between the slider 12 and the piston 3. The confinement of this volume creates a hydraulic stop. The oil volume is connected to a hydraulic circuit 13 which is connected to the expansion chamber and includes a check-type device 14 which can resupply the oil volume during the phase change and can move the slider 12 again. The system operates only on one side of the piston. Since the slider 12 is continuous, there is an equivalent system on the other side of the piston. Thus, a hydraulic circuit equivalent to the hydraulic circuit 13 is connected to the compression chamber. In this embodiment, the slider 12 is formed by a rigid pin passing through a hole formed in the piston 3, which is different from the internal channel 10 for the passage of fluid. The pin is provided at least at the ends of the internal radial extension and the external radial extension, and the extensions ensure the function of the shut-off valve. Thus, in this embodiment, the shut-off valve forms a single piece with the pin.

[0087] Figure 18 , Figure 19 , Figure 20 and Figure 21 shows a fourth embodiment. In this embodiment, the shut-off valve is not fastened to the slider 12 but to the piston 3. More specifically, the shut-off valve includes two flexible plates 120 fixed on either side of the piston 3 and fastened to the piston. The slider 12 includes a plurality of pins located in the expansion chamber 5 and the compression chamber 4 and mounted in a channel 20 passing through the piston 3 and opening on either side of the piston 3. In the embodiment shown in ( Figure 18 ), the piston 3 includes three channels 20 which respectively accommodate the pins and three internal channels 10 for the passage of oil. The length of the pins is sufficient to ensure the "separation" of the plates 120 from the piston 3.

[0088] As Figure 19 and Figure 20 shown, the plates are able to move from the closed position to the open position. In the closed position, the plates are arranged to rest against the piston so as to close the compensation orifice 11, and in the open position, the plates are pushed away from the piston under the thrust of the pins, thus releasing the compensation orifice 11 under the action of the pins.

[0089] Thus, Figure 19 shows the "actual" compression phase. The plate located on the side of the compression chamber 4 rests against the surface of the piston 3 associated therewith, which closes the compensation orifice 11 leading to the compression chamber 4, while the plate located on the side of the expansion chamber 5 is pushed back by the slider 12, thus opening the compensation orifice 11 leading to the expansion chamber 5.

[0090] Figure 20Shows the "actual" expansion phase. The plate on the side of the expansion chamber 5 is placed against the surface of the associated piston 3, which closes the compensation orifice 11 leading to the expansion chamber 5, while the plate on the side of the compression chamber 4 is pushed back by the slider 12, thus opening the compensation orifice 11 leading to the compression chamber 4.

[0091] By selecting the rigidity of the valve and the length of the pin, the responsiveness of the system and its filtering range (filtering frequency and amplitude), i.e., the range in which the expansion chamber 5 and the compression chamber 4 are directly connected, can be adjusted so that the piston cannot transmit force (oil - free movement). Figure 21 Shows the position of the valve during the filtering phase.

[0092] The present invention (and these different embodiments) is particularly applicable to the design of dampers used in the front or rear suspension systems of land vehicles (especially bicycles, motorcycles, cars, etc.).

[0093] The present invention has been described by way of example. It should be understood that those skilled in the art can implement different variants of the present invention.

[0094] List of reference numerals

[0095] - 1 Body

[0096] - 2 Rod

[0097] - 3 Piston

[0098] - 4 Compression chamber

[0099] - 5 Expansion chamber

[0100] - 6 Energy dissipation device

[0101] - 7 Hydraulic circuit

[0102] - 8 Compensation chamber

[0103] - 9 Floating piston

[0104] - 10 Internal channel

[0105] - 11 Compensation orifice

[0106] - 12 Slider

[0107] - 13 Hydraulic circuit

[0108] - 14 Check device

[0109] - 15 Displacement direction of the slider - 16 "Restricted" oil volume

Claims

1. A device for volume compensation of damping liquid for a damper, used in all suspension components of bicycles and other vehicles, the device for volume compensation of damping liquid for a damper comprising: - At least one hollow cylindrical body (1), the at least one hollow cylindrical body containing fluid and having at least one end provided with an axial passage for the passage, sealing and guiding of a rod (2), the rod being fastened to a piston (3), the piston moving translationally inside the body and dividing it into two different working chambers, one working chamber constituting a compression chamber (4) and the other working chamber constituting an expansion chamber (5), the compression chamber (4) and the expansion chamber (5) being directly connected to each other via one or more internal passages (10) in the piston (3) for the passage of fluid through the piston (3) and one or more compensation orifices (11) leading to the compression chamber (4) and leading to the expansion chamber (5) in the region of the piston (3). - A shut-off valve for the compensation orifices (11) leading to the compression chamber (4) and leading to the expansion chamber (5). - At least one rigid member (12), the at least one rigid member being inserted between the shut-off valves leading to the compression chamber (4) and leading to the expansion chamber (5), the rigid member (12) being capable of translational movement between a first end position and a second end position in the axial direction of the rod (2) and in the axial direction of the body (1), in the first end position, the compensation orifice (11) leading to the expansion chamber (5) being closed by the shut-off valve and the compensation orifice (11) leading to the compression chamber (4) not being closed by the shut-off valve, in the second end position, called the compression position, the compensation orifice (11) leading to the compression chamber (4) being closed by the shut-off valve and the compensation orifice (11) leading to the expansion chamber (5) not being closed by the shut-off valve, the compensation orifices (11) and the rigid member (12) being positioned such that it is not possible to simultaneously close both the compensation orifice leading to the compression chamber and the compensation orifice leading to the expansion chamber, and such that the total cross-sectional area of the compensation orifices (11) not closed by the unactuated rigid member still allows oil to pass directly through. Characterized in that the rigid member (12) is arranged to move translationally freely through a passage formed in the region of the piston (3) different from the internal passage (10).

2. The device for volume compensation of the damping liquid for a damper according to claim 1, characterized in that, The shut-off valve includes two flexible plates, the two flexible plates being fixed on either side of the piston (3) and fastened to the piston, the plates being capable of moving from a closed position to an open position, in the closed position, the plates being arranged to rest against the piston so as to close the compensation orifices (11), in the open position, the plates moving away from the piston under the thrust of the rigid member, thus releasing the compensation orifices (11).

3. The device for volume compensation of the damping liquid for a damper according to claim 1 or 2, characterized in that, The rigid part (12) includes a pin that translates through a passage in the piston (3) that is different from the internal passage (10).

4. The device for volume compensation of the damping liquid for a damper according to claim 3, characterized in that, The shut-off valve is arranged at the end of the pin.

5. The device for volume compensation of the damping liquid for a damper according to claim 1 or 2, characterized in that, The shut-off valve and the rigid part form a single piece.

6. The device for volume compensation of the damping liquid for a damper according to claim 1 or 2, characterized in that, The passage for the rigid part (12) to translate through is arranged between the piston and the body (1).

7. The device for volume compensation of the damping liquid for a damper according to claim 6, characterized in that, The rigid part (12) contacts the body (1) in the radial direction.

8. The device for volume compensation of damping liquid for a damper according to claim 1 or 2, characterized in that, The rigid part (12) passes through the piston (3) with a non-discontinuous cross-section.

9. The device for volume compensation of damping liquid for a damper according to claim 6, characterized in that: · The rigid part (12) closes the oil volume (16) on the compression side during the compression phase, or on the expansion side during the expansion phase, and the oil volume decreases as the rigid part (12) approaches its end position, · The shape of the rigid part (12) is such that the volume (16) closes before the rigid part (12) has a "solid" interaction with the piston (3), · The oil volume (16) is connected to the expansion chamber (5), or to the compression chamber (4), via a hydraulic circuit (13), and the hydraulic circuit also includes a check-type device that allows oil to move only from the expansion chamber (5), or from the compression chamber (4), towards the volume (16).

10. The device for volume compensation of the damping liquid for a damper according to claim 1 or 2, characterized in that, The rigid part (12) and the piston (3) have complementary shapes, which allows the orifice (11) to be closed in a progressive manner, and the orifice (11) is completely closed before any solid contact between different parts.

11. The device for volume compensation of the damping liquid for a damper according to claim 1 or 2, characterized in that, The device includes a compensation chamber (8) that is directly connected to the compression chamber (4) and the expansion chamber (5).

12. The device for volume compensation of the damping liquid for a damper according to claim 11, characterized in that, The compensation chamber (8) is connected to the compression chamber (4) and the expansion chamber (5) via the internal axial passage of the rod (2), and the internal axial passage of the rod (2) is fluidly connected to the internal passage (10) of the piston (3).

13. The device for volume compensation of damping liquid for a damper according to claim 12, characterized in that: · The compensation chamber (8) is fastened to the rod (2), · The compensation chamber (8) is positioned opposite the piston (3), · And the compensation chamber is located outside the body (1).

Images