Proportional rolling shock absorber

Abstract

The variable damping damper is an invention designed to improve the performance of linear-acting suspensions or shock absorbers by modulating the oil flow. This applies to shock absorbers and hydraulic forks equipped with a gas accumulator. The principle of the invention is to use the movement of the gas accumulator piston to move a variable-section needle within the hydraulic rod volume compensation channel, regulating the flow rate according to the suspension compression. Applications include general mechanics, public transportation (rail, bus), automobiles, bicycles and motorcycles, and aeronautics, particularly shock absorbers and suspension forks. Currently, the rebound damping of a suspension is greatest when the shock absorber is fully compressed. Conversely, the hydraulic rebound damping is least damped when the spring force is strongest.The present invention proposes the opposite, for greater safety and equal reaction speed. The innovation offers a hydraulic suspension damping system consisting of a flow limiter that is adjusted by the position of the gas accumulator piston in the suspension. The flow limiter adjusts automatically according to the shock absorber's compression and effectively dampens its hydraulic circuit. Thanks to this innovation, the hydraulic rebound damping is most effectively damped when the spring force is greatest. See Figure 5 for abbreviations.

Description

Title of the invention: Proportional lamination shock absorber

[0001] The present invention relates to linear action suspensions or shock absorbers, they are found on cars, motorcycles, bicycles, airplanes, trucks, trains and serve to improve road holding, safety and comfort. More particularly, this concerns hydraulic lamination shock absorbers comprising a pressurized gas accumulator whose pressure increases when the shock absorber is compressed. The field of suspension is a field which requires a lot of attention, feeling and experience.

[0002] There are two main forms of suspension manufacturing:

[0003] -the suspension fork which has the functions of shock absorber and wheel support.

[0004] -the shock absorber whose operation I will briefly detail.

[0005] Both are concerned. 1. Description of figures#:

[0006] [Fig.l]: A shock absorber in the state of the art.

[0007] [Fig.2]: State-of-the-art shock absorber detailed.

[0008] [Fig.3]: Pre-dimensioned technical drawing for testing a rolling damper proportional.

[0009] [Fig.4]: Proportional rolling shock absorber ([Fig.3]) in compressed position.

[0010] [Fig.5]: Detailed proportional rolling shock absorber head.

[0011] [Fig.6]: Detail of the proportional rolling needle

[0012] [Fig.7]: Comparative table of classic and rolling shock absorber settings proportional.

[0013] [Fig.8]: Shock absorber 100: simultaneous proportional compression and expansion.

[0014] [Fig.9]: Shock absorber 110: compression, proportional expansion with separate circuits and individual settings

[0015] [Fig. 10]: Shock absorber 120: compression, proportional rebound with separate circuits and individual adjustments with compression overpressure circuit.

[0016] [Fig. 11]: Shock absorber 130: classic compression and proportional piston rebound.

[0017] Global nomenclature:

[0018] 1: Shock absorber.

[0019] 2: Hydraulic circuit for compensating the volume of the rod, or channel (2).

[0020] 3: Gas accumulator piston, or rod volume compensation piston.

[0021] 4: Shock absorber rod.

[0022] 5: Shock absorber barrel.

[0023] 6: Gas accumulator.

[0024] 7: Gas accumulator piston assembly (8) + proportional throttling needle (9).

[0025] 8: Gas accumulator piston of the proportional throttling assembly (7).

[0026] 9: Proportional throttling needle.

[0027] 10 Proportional damper head.

[0028] 11 Sealing O-ring.

[0029] 12 Assembly nut.

[0030] 13 Bleed screw with seal.

[0031] 14 Flow limiter.

[0032] 15 Overpressure check valve.

[0033] 16 Flow direction check valve.

[0034] 17 Expansion flow direction check valve.

[0035] 18 Compression flow direction check valve.

[0036] 30 Shock absorber spring

[0037] 31 Slow compression and rebound adjustment wheel at the beginning of the stroke.

[0038] 32 Deformable end-of-stroke rebound washers.

[0039] 33 Deformable fast compression washers.

[0040] 34 Main rolling piston.

[0041] 40 Slow compression and rebound hydraulic flow at the beginning of the stroke.

[0042] 41 Fast compression hydraulic flow.

[0043] 42 End-of-stroke rebound hydraulic flow.

[0044] 43 Oil

[0045] 44 Gas 1.: Plan of the restriction section of the channel (2). 2. Operation of a current shock absorber#:

[0046] A shock absorber (1) is generally mounted on a transport vehicle and is used to absorb variations in the flatness of the terrain. It is located between what is being transported and the terrain to protect it from shocks. It can also be mounted between the wheel and the chassis of a vehicle where it has two main qualities: adapting to the shape of the terrain so that the wheel can produce an effective change of direction, but also absorbing shocks as for a vehicle that is landing. The job of the shock absorber is to absorb by deforming, becoming shorter under the stress of an impact and returning to its initial length in a rapid and controlled manner. What complicates the role of a shock absorber is that it must simultaneously absorb shocks, that is to say dissipate energy with strong hydraulic rolling control, but also adapt to the geometry of the terrain in an ultra-reactive manner with freer adapted hydraulic rolling.

[0047] The shock absorber is generally attached by the end of the barrel (5) on one side and by the end of the rod (4) on the other side, see [Fig.l] and 2.

[0048] A conventional shock absorber is composed of a body (1) and a spring (30).

[0049] The spring is caught between the body of the barrel (5) and the attachment end of the rod (4), the spring will deform under the stresses and suddenly restore the energy stored by the deformation.

[0050] The body of the sealed barrel comprises the hydraulic part (43), a rod (4) provided with a rolling piston (34), the rolling piston is located in the barrel and is driven in translation by the rod in the barrel, the sliding pivot connection between the rod and the barrel is sealed. The connection between the rod and the piston is fixed. The hydraulic part is used to control the movements of the shock absorber in compression for stresses, shocks, and in relaxation for the return energy of the compressed spring.

[0051] The piston is provided with a seal on its radial external diameter in sliding pivot connection with the barrel, and with hydraulic flow limiters (40-41-42) on these axial faces.

[0052] In operation, the rod enters the barrel under the effect of a constraint, the barrel is sealed and the oil incompressible. If the oil cannot leave the barrel, the rod cannot enter it. It is therefore necessary to provide the barrel with a gas accumulator, that is to say a sealed gas reservoir whose volume can decrease to allow the rod to enter the barrel freely and in a sealed manner.

[0053] The gas accumulator of a conventional shock absorber compresses to compensate for the volume of the piston rod (4), which enters the barrel (5) filled with oil.

[0054] Since the oil is incompressible, the space cannot be reduced by a quantity of oil; the return of the rod into the body of the shock absorber involves a displacement of oil (2) and in general the reduction of a volume filled by a gas (44), which is called a gas accumulator (6). [Fig.l].

[0055] On a conventional shock absorber, a piston (3) ensures the seal between the gas in the accumulator (6) and the oil in the barrel (5). This piston must move in such a way as to compensate for the volume of rod which enters the barrel. This compensation is strictly equal to the volume displaced by the rod. The placement of the piston (3) is therefore always strictly dependent on the insertion of the rod (4) into the barrel (5).

[0056] The suspensions are therefore composed of a mechanical spring, metallic (30) [Fig.l] and2 or gaseous, and a hydraulic part (43). The hydraulic part is used to control the speed of depression, and return of the suspension. The depression of the suspension is called compression phase and its return to the initial position (return to the longest relaxed position) is called relaxation.

[0057] 3. The current main settings are: - The spring hardness (30) in metal which remains linear. A usual spring for mountain bike: 4001bs*3inch=544kg compressed, or 5335N of force - Compression of the air volume (44) of the gas accumulator (6) which makes the suspension firmer at the end of travel. This spring adds a high return energy to position. The compression and relaxation force of an air spring is said to be progressive. - The throttling, the rolling of an oil displacement (40,41,42). This is divided into two for the direction of operation: For the depression we speak of compression, and for the return in place we speak of relaxation.

[0058] These two phases are themselves divided into two “flows”.

[0059] For compression, we speak of “slow compression” (40) for medium and small shocks and “rapid compression” (41) for large shocks.

[0060] For the relaxation we speak of “start of stroke relaxation” (40) and “end of stroke relaxation” (42). (see [Fig.2] and table [Fig.7])

[0061] 4, Details of current operation:

[0062] The hydraulic compression and expansion circuits which are mainly made up of two systems see [Fig.2]: - Firstly a simple circuit with a manually adjustable and stationary flow limiter (40), this rolling consists of a point (31) which more or less obstructs the compression and expansion oil circuit. This is called "low speed compression" adjustment and "start of stroke expansion" adjustment. This adjustment can be common to compression and expansion, or be separate for compression or expansion. - Secondly, a circuit obstructed by a layering of thin washers (41 and 42), which deform more or less depending on the load to be managed. This layering is adjustable in stiffness by the number and thickness of the layered washers by dismantling the shock absorber. It is therefore a second parallel rolling circuit which can be released according to an adjustable threshold.

[0063] In compression (41), these washers release more or less a second passage of oil depending on the intensity of the shock.

[0064] In relaxation (42) they open more or less depending on the depression of the shock absorber.

[0065] So the harder the spring pushes, the more they are open. We can talk about degressive rolling in compression or in expansion on current hydraulic circuits.

[0066] This adjustment is called "high speed compression" (41), for compression and "end of stroke speed", (42) for expansion. These two adjustments can be found on the main piston (34) of the shock absorber, or on the hydraulic flow (2) which goes to the gas accumulator ([Fig.l]). 5. Order of magnitude#:

[0067] In fact a 400*3 spring is commonly used, that is to say 400Lbs per inch with 3 inches of spring deformation, or 400*3=1200Lbs. 1200 Lbs=544Kg

[0068] The shock absorber therefore has a return energy in position of 544 kg to dissipate.

[0069] Calculation of the force at the wheel:

[0070] On a bicycle, the shock absorber travel is generally multiplied linearly, progressively or degressively by a lever arm, calculation of its ratio:

[0071] Shock absorber travel 76mm, wheel travel: 200mm

[0072] Suspension ratio: 200 / 76=2.63

[0073] The force ratio is proportional to the travel ratio, therefore:

[0074] 544 / 2.66=207Kg

[0075] The fork of a downhill mountain bike is generally set up with similar characteristics to the rear suspension and pushes around 207Kg fully compressed.

[0076] So we have about 207kg rear wheel + 207Kg front wheel to control on a 15Kg bike for an 80Kg rider equipped. So 207+207 = 414Kg and 414 / 80 = 5.2, the suspensions help, on the example of a downhill bike to control a resultant force of up to 5 times the rider's weight. 6. Current Use#:

[0077] The braking of the hydraulic compression (40-41) or expansion (40-42) rolling allows to absorb large shocks. This firming also avoids having to undergo geometry changes when braking, and having to compensate for these changes, just before, or during a turn.

[0078] Strengthening the rapid compression hydraulic circuit (41) makes it possible to print a change of direction by pressure in a more clear and efficient manner on a downhill bike for example.

[0079] The flexibility of the hydraulic compression (40-41) or relaxation (40-42) rolling allows the wheel to remain as close as possible to the profile of the terrain by opposing a low compressive resistance in front of an obstacle. This flexibility also allows the wheel to return as quickly as possible to its place for the next obstacle.

[0080] On mountain bikes I noticed my tendency to use these two different settings: • Firstly for smooth tracks made up of jumps:

[0081] Slow compression and relaxation for aerial sections consisting of springboards and landing jumps. That is to say, significant hydraulic rolling which strongly controls the compression and relaxation speeds of the suspension. This makes it possible to limit or eliminate unwanted movements in springboard-type curves (identical for a bend), or unwanted movements in the air due to sudden movements of the wheels returning to their places. The sudden return of a wheel to its position can cause rotational movements in the air due to the effect of inertia. on a bike. Some riders (a World Cup downhill rider in Leogang, Austria, in 2017 on the final jump) tip forward after a very long jump performed at 80 km / h.

[0082] Slowing down the suspension return speed decreases, eliminating these risks of tipping.

[0083] The problem with this "slow" setting is the grip, which requires a high speed of movement of the shock absorber to stick to the ground. In fact, the suspension hardens over a succession of impacts while remaining partially compressed, which causes a loss of grip. • Secondly, for downhill competition tracks made up of pebble roots, where you have to go fast to win:

[0084] The adjustment allows for optimizing speed and grip: Compression and rebound set very fast for rough sections where grip is paramount. For this type of adjustment, however, the fast compression circuit (41) can be used to apply hydraulic threshold rolling (see explanation line 170) which allows for a sharper change of direction by transmitting more support to the ground.

[0085] The problem with this setting: controlling the speed of return to position of the shock absorber to avoid the situation of the rider seen previously. The order of magnitude of the force to be controlled on a mountain bike for a downhill bike shock absorber spring of a 75Kg rider is approximately 544Kg.

[0086] Problem with this setting: the lack of control over the suspension's rebound during larger impacts, which causes unwanted movements and loss of grip. Too soft a compression also causes a blur in changes of direction when applying pressure to the bike and a risk of bottoming out (impact at the shock absorber's end) during compression. 7. The main problem of the state of the art#:

[0087] The end-of-stroke relaxation is achieved using deformable washers (42). These washers are most deformed when the shock absorber has the most load to release, i.e. when it is fully compressed. When the 544 kg of our shock absorber spring (30) are pushing, this is when our current hydraulic rolling is most open. This results in a very high return speed at the start of the return to position; this is a movement that disrupts the steering. Please note that the speed at the start of the return to position is called the end-of-stroke relaxation.

[0088] To illustrate this problem, I mention a range of use extended in speed or load of different types of vehicle with a decreasing adjustment : A grand prix motorcycle which must be efficient at 60 km / h on bends but also at 300 km / h, a lorry of 10 tonnes empty and 44 tonnes loaded, or the TGV which travels at 340 km / h or 120 km / h with more or less load human with a “degressive” hydraulic rolling, that is to say the most open in the relaxation phase when the mechanical spring is the most compressed.

[0089] The present invention relates to the control of the speed at any working point of the shock absorber.

[0090] Currently, two opposing settings seem effective depending on what you are looking for: grip and speed or stability and safety. Nowadays, you can't have both without touching knobs or dismantling the suspension.

[0091] Recently, a major brand has marketed an electronic system that influences rolling according to the type of terrain. The system I propose has, despite this, advantages: no battery, influence on rolling on a large scale, no response time and finally no external intervention.

[0092] The firmness or flexibility of a shock absorber has strategic, safety importance. 8. Proposed solution#:

[0093] Ideally, for downhill mountain biking, you would need a suspension with low, flexible, and responsive hydraulic lamination for the first 50% of the travel. Then, for larger shocks, you would need a firmer response at the end of the stroke, with progressive lamination, proportional to the stresses.

[0094] The invention concerns the hydraulic part of the suspension (40,41,42 [Fig.2]), and proposes the use of a variable flow limiter on this circuit, with a rolling which varies according to the depression of the suspension.

[0095] This is a system which combines the two settings detailed in paragraph 6 “current use” by moving the piston (7) of the gas accumulator. The piston moves proportionally to the depression of the shock absorber or fork and acts as a flow limiter on the hydraulic circuit (2) of the shock absorber.

[0096] My invention proposes equal but reversed management of relaxation speeds compared to the state of the art.

[0097] In fact, the speed of return to position of the shock absorber is essential.

[0098] In the state of the art, suspensions have a high end-of-stroke flow rate, when the spring (30) dissipates the most energy, which is dangerous.

[0099] The flow rate at the start of the race is more restricted, which is detrimental to grip.

[0100] The hydraulic flow control of a shock absorber in the state of the art is decreasing.

[0101] I propose a suspension that returns to place at the same speed but with a reversed speed control scheme.

[0102] The hydraulic flow control of the proportional rolling damper is progressive.

[0103] The proportional rolling shock absorber has a restricted flow at the end of the stroke, for safety, but it is rapid in rebound at the start of the stroke, for grip.

[0104] My system has the advantage of making the rolling power proportional to the depression of the shock absorber, to the power to be managed.

[0105] Thanks to this innovation we obtain the ideal setting, the shock absorber is flexible at the beginning of the stroke and significantly slowed down at the end of the stroke during the compression and rebound phases. It is therefore a high-performance shock absorber for grip but also perfectly safe, i.e. slow at the end of its rebound stroke. It has a rolling adapted to all shock potentials and guarantees a controlled return speed to the position even when the shock absorber is most compressed.

[0106] Note: for the operation of shock absorbers we also speak of natural frequency, that is to say, the shock frequency for which a shock absorber is efficient. This frequency can be acted on by a flow regulator on the hydraulic rolling circuit of the shock absorber. Our invention therefore has an infinite natural frequency, adjustable according to the terrain used.

[0107] Second remark: the prototype presented [Fig.8], with an equal influence in compression and in expansion, is a prototype technical solution to carry out the first measurements. To have an effective proportional shock absorber for the envisaged application, the compression and expansion circuits can be separated, and a calibrated overpressure valve can be added to the compression. The hydraulic-pneumatic diagrams [Fig.8] to 12 explain different possible configurations for the proportional throttling shock absorber.

[0108] 9. Operation of the proportional rolling damper:

[0109] Detail of the operation of a shock absorber equipped with proportional rolling ([Fig.3]-4).

[0110] On this shock absorber (1), we have a body composed of the barrel (5), and the rod assembly (4), main rolling piston (34), a spring (30), a rod volume compensation circuit (2), a gas accumulator (6).

[0111] The spring (30) is compressed when the rod (4) enters the barrel (5) it allows the shock absorber to return to the most relaxed position.

[0112] On the proportional rolling shock absorber see “head” [Fig.5], we added the piston-needle assembly (7) in the gas accumulator (6).

[0113] The piston-needle assembly (7) comprises the needle (9) and the piston (8). The needle (9) and piston (8) connection is fixed and sealed. The main axis of the needle (9) is concentric or offset parallel to the axis of the piston (8). The needle is located in the hydraulic rod volume compensation channel (2). The shape of the channel (2) and the needle make it possible to vary the oil passage section from complete to zero. This minimum passage section must be adapted empirically to the application concerned.

[0114] The shape of the channel and the shape of the needle influence the behavior of the shock absorber.

[0115] The needle ([Fig.5]-6) has one end connected to the piston (8) with a small 0(a) along the length (d), this diameter evolves into a cone along the length (c) up to a larger diameter (b).

[0116] Its final end is a sliding pivot connecting cylinder from 0(b). The transition from 0(a) to 0(b) is conical for the example but can also be convex, concave, stepped in operation, cycloidal, have a constant 0(a) over a part of the length (c) and an evolution to be chosen from the previous list to arrive at the diameter (b). A reduction of the final diameter towards 0(b) is possible on the expansion circuit to allow a rapid return despite the mass inertias of the system. The different possibilities of shapes serve to best adapt the shock absorber to the application. The length (d) is functional, it is greater than or equal to the travel of the piston (8), the calculation of the travel is carried out below.

[0117] Calculation of the piston travel (8) in the case of our example prototype shock absorber [Fig.3]-4: - To calculate the travel of the piston (8) we must know the total volume of the rod (4) which will enter the sealed barrel (5), in fact, the piston (8) when moving will compress the same volume of gas.

[0118] Rod (4): diameter 12.5mm travel: 76mm

[0119] Volume = ir x R2 x travel = 6.252*3.14*76=9322 mm cube.

[0120] We have the volume of rod (4) to compensate, we know the diameter of the piston (8), so we can calculate its displacement in the gas tank:

[0121] Piston (8): diameter: 27mm, volume to be compensated: 9322mm cube.

[0122] Piston air: (27 / 2)2 x ir = 572.56mm2

[0123] Travel = volume / area of ​​the piston (8) = 9322 / 572.56 = 16.3 mm. This is the dimension (p)

[0124] On our prototype the length (c) is 19.5, so that the passage section blocked by the needle is not completely blocked.

[0125] The needle has two flats at its top which allow the evacuation of the oil located in the bottom of the hydraulic channel when the needle moves towards this bottom.

[0126] The 0(b) of height (h) is adjusted to the 0(e) of the channel (2) in translational guidance.

[0127] The channel (2) is here made of two holes. The first starts radially from the sealed barrel (5) of the shock absorber in the direction of the axis of the piston (8) and measures a 0(g), the second hole starts coaxially with the axis of the compensation piston (8) and measures a 0(e), it joins perpendicularly the first hole and the axes of the two drillings have one thing in common. The drilling must be deep enough so that the needle (9) is not at the bottom when the shock absorber is in the longest relaxed position. The dimension (j+k) is the dimension of the drilling of the channel (2) parallel to the axis of the piston (8) up to the radial drilling of the barrel (5). The junction height (j) is also functional, it determines the dimension (d) on the needle.

[0128] The dimension (j) is given by the design of the shock absorber, the dimension (m) by the design of the piston needle connection.

[0129] Characterization of the dimension (d) of the needle:

[0130] The placement of the gas tank also influences the dimension (d).

[0131] We have (i) = (j) - 1 / 2(0g)

[0132] and the dimension (d) is here framed, (m)+(j)>(d)>(m)+(j)-l / 2(g).

[0133] The needle (9) is fixed on one side to the piston (8) which varies its position in the hydraulic rod volume compensation channel (2). The needle (9) on the side opposite its fixing is in the rod volume compensation channel. Its shape varies from 0(b) at its top to its thinnest 0(a) at the level of the fixing with the piston.

[0134] Note: 0 b = 0 e

[0135] When the shock absorber is in its relaxed position, the needle is at its highest in the channel (2), the part which obstructs the passage section of 0(e) is the section of the needle of diameter (a).

[0136] As: Area 0e - Area 0a = Area 0g. the passage is therefore free (it has a minimal pressure loss).

[0137] In its compressed position, the needle has descended to the lowest point in the channel (2), the part which obstructs the passage section of 0(e) is the section of the needle of diameter (n) with 0(n)<0(b) and 0(n)>0(a).

[0138] Therefore: Area 0e - Area 0n < 0g the passage is restricted.

[0139] The needle leaves the passage of the channel (2) completely open when the shock absorber is in the long, relaxed position. When the shock absorber is completely compressed, the needle closes the channel as much as possible. The rolling can be adapted at each point of the shock absorber's stroke.

[0140] The piston-needle assembly (7) moves between two positions determined by the insertion of the rod (4) into the shock absorber: - the initial position, when the rod is in its most extended position, when the shock absorber is longest, the gas volume (44) the gas accumulator (6) the largest. - The final position, when the rod (4) is at its most retracted position, when the shock absorber is shortest, the volume of the most compressed gas accumulator.

[0141] Notes on the proportional rolling system: - For optimal control it is better to separate the compression and expansion circuits.

[0142] It is possible to produce a piston (8) equipped with two needles (9) of different profiles which would be parallel to the axis of the piston but off-center see ([Fig.9]) “shock absorber 110”. - It seems that the ideal shock absorber for use on mountain bikes, motorcycles or cars is the "130 shock absorber". It includes proportional hydraulic lamination in rebound and classic lamination by deformable washers (shim suspension). In fact, the current hydraulic compression by opening on large shocks allows the vehicle to maintain its position, the part making the shock absorber firmer in compression is the spring. - - An adjustment is possible on the needle (9) with proportional rolling, we We can separate the needle in two in a plane perpendicular to the axis along the length (d) and add a threaded connection between the two parts of the needle in order to modify the length (d). The end of 0(b) of the needle would come out of the shock absorber in a sealed manner to allow the movement of the length (c) relative to the rolling channel. The part of length (d) would be in pivot connection with a rotation lock. This adjustment can adapt the proportional rolling to different spring hardnesses. - One of the operating limits of any hydraulic shock absorber is oil cavitation, which is counteracted by the pressure of the gas accumulator (6). Flow rates and pressures must be adapted if measurements demonstrate this situation. - The rolling needle restricts the passage (2) of the damping oil and therefore acts directly on the vibration harmonics of the suspension. The profile of the needle influences possible chattering effects of the suspension.

[0143] The principle of the invention works with shock absorbers or forks whose system includes a gas accumulator. For a suspension fork, it is possible to add a gas accumulator to have the benefit of proportional rolling. 10. Preamble to the claims#:

[0144] 1) The proportional rolling damper device, operating with forks or shock absorbers equipped with a gas accumulator.

[0145] In the state of the art a suspension is composed of a sealed cylindrical barrel (5), of a rod (4). The barrel and the rod have at their ends attachment points to transmit the stresses and movements to the shock absorber. The rod (4) is in a sealed sliding pivot connection with the barrel (5). The barrel (5) is filled with oil. The end of the rod (4) which is located in the barrel is equipped with a main rolling piston (34). The piston (34) is fixed to the rod (4) in a sealed manner, and is in a sealed sliding pivot connection with respect to the barrel (5). The rolling piston (34) is equipped with a high-speed compression hydraulic circuit (41) obstructed by the deformable washers (33). It comprises an end-of-stroke expansion hydraulic circuit (42) obstructed by deformable washers (32). The hydraulic circuits 41 and 42 open proportionally to the constraints, the more force there is to dissipate, the less the circuit is braked. The rod (4) is equipped with a low-speed compression and start-of-stroke expansion hydraulic circuit (40) adjustable in flow by a point (31). The point (31) is mounted on a sealed threaded connection in the rod (4). It is equipped with a wheel on the outside of the rod and more or less obstructs the channel (40).The rod volume that enters the barrel (5) discharges oil to the gas accumulator (6). The cylindrical gas accumulator (6) has a sealed chamber filled with gas (44) under pressure separated in two by a sealed piston (3). The sealed piston (3) is in sealed sliding pivot connection in the cylinder of the gas accumulator (6). The piston (3) separates the oil from the gas. The oil (43) communicating between the barrel (5) and the gas accumulator (6) by the hydraulic circuit (2) is assumed to be purged of air. The gas accumulator (6) serves to compensate for the rod volume that enters the barrel, it keeps the oil under pressure to avoid cavitation. The circuit (2) and can be used to make hydraulic control adjustments of the suspension speed.

[0146] The proportional throttling device is innovative in that a needle (9) is fixed to the piston (3 or 8) of the gas accumulator (6) and more or less obstructs the circuit (2) depending on the depression of the rod (4).

[0147] 2) Device according to paragraph 1, characterized in that the rolling damper proportional, comprises a rod volume compensation piston (3) which is replaced by a new assembly (7) consisting of the piston (8) and the needle (9). The needle (9) is tightly fixed on the piston, its main axis is concentric with the axis of movement of the piston (8), and the rod volume compensation channel (2) is designed so that the needle (9) can move inside the channel (2) coaxially.

[0148] 3) Device according to paragraph 2, is characterized in that the design and shape of the needle (9) influences the hydraulic flow in the channel (2). The needle (9) has a sealed attachment with the piston (8). The needle has a variable shape along its length. At the attachment with the piston (8), its 0(a) remains constant along the length (d), it then evolves into a cone along the length (c) up to a 0(b). The 0(a) < 0(b), its last length (h) is a translational guide adjusted from 0(b) with h=0.8x0(b), it has two flats to allow the oil from the bottom of the channel (2) to circulate.

[0149] 4) Device according to paragraph 2, characterized in that the shape of the hydraulic channel (2) interacts with the shape of the needle (9) to allow the oil (43) to pass. The hydraulic channel (2) starts with an 0(g) from the top of the rolling barrel (5), in an area opposite the rod (4) and not occupied by the main rolling piston (34) when the shock absorber is fully compressed. This drilling starts radially towards the operating axis of the rod volume compensation piston (8), a second drilling of the channel (2) of 0(e) starts from the top of the gas reservoir (6) concentric with the axis of the needle (9) fixed on the piston (8), this drilling passes in the axis of the first drilling of 0(g) at the height (j) and is of depth (j+k). The restriction section (45) is the opening caused by the drilling of the 0(g) by the drilling of the 0(e) at the height (jl / 20(g)).The 0(e) is dimensioned so that the section of the 0(a) of the needle (9) coaxial with the 0(e) located in the channel (2) leaves a passage section equivalent to the section of 0(g) which brings the rod volume compensation oil. Area 0(g) < Area 0(e)-area 0(a). When the 0 (a) of the needle is in the 0 (e) of restriction of the channel (2) there is at least conservation of the section of 0 (g) over the entire length of the channel to minimize the pressure losses when the oil passes.

[0150] 5) Device according to paragraph 2, characterized in that the piston (8) moves in the pressurized gas accumulator, the piston (8) is sealed between the oil which comes from the barrel (5) and the gas (44) of the accumulator (6). When the rod (4) enters the barrel (5) it displaces a volume of oil corresponding to the volume of the rod (4) retracted into the barrel (5). This volume of oil causes the piston (8) to move in height which compresses a volume of gas (44), this volume is strictly identical to the volume of the rod (4) retracted into the barrel (5). This strict movement is used to exactly place the needle in the channel (2). The maximum movement of the piston (8) corresponds to the length (p) induced by the total compression of the shock absorber, the needle therefore moves a height (p) in the channel (2), the needle will therefore have a strictly proportional placement in relation to the retraction of the rod.For the assembly to operate, the oil (43) must be purged of air and the sizing must take into account the vaporization point of the oil used; the oil remains in its liquid domain thanks to the initial pressure of the gas (44).

[0151] 6) Device according to paragraph 3-4-5, is characterized in that the needle (9) placed in the channel (2) leaves a variable oil passage section (43) in the channel (2) at its restriction section (45). This section varies from 0 (g) > 0(e)-0(a) when the shock absorber is relaxed to the section 0(g) > 0(e)- 0(n) with 0(a) < 0(n) < 0(b). When the shock absorber is fully compressed it moves the needle (9) by a height (p) and places the section of 0(n) in the restriction section of the channel (2). The 0(n) is greater than the 0(a) and creates a pressure drop by reducing the oil passage section in compression and in relaxation of the shock absorber. In the case of a needle (9) conical we have a linear variation of the passage section of the oil (43) in the channel (2). The section varies from 0(g) = 0(e) when the shock absorber is relaxed, to, 0(g) > 0(e)-0(n) when the needle has moved by the length (p). We can deduce the dimensions of the needle and the channel:

[0152] *Dimension (j) is a construction dimension; it is the junction height of the diameter of the drilling 0(e) and 0(g).

[0153] *Dimension (m) is another construction dimension, it is the dimension between the junction face of the piston (8) and the needle (9) and the start of the drilling of 0(e) in the shock absorber head (10) at the level of the fixing of the gas accumulator.

[0154] *The dimension (p) is the maximum displacement of the piston (8) in the gas tank (6)

[0155] *Dimension (i) is the dimension between the start of drilling 0(e) in the shock absorber head and the restriction section, (i)=(j)-(l / 2x0(g))

[0156] *Air section 0(a) = Air section 0(e) - Air section 0(e)

[0157] *The 0(a)<0(n)<0(b), the ratio (Air section 0(e) - Air section 0(n)) / (Air section 0(e) - Air section 0(a)) is to be determined empirically for the application.

[0158] We have:

[0159] *The dimension (d) of 0(a) of the needle between its attachment with the piston (8) and the beginning of the length (c), the Length (d) is framed by (m)+(j)<(d)<(m)+(i). See figure (5).

[0160] *Dimension (c) is the transition length from 0(a) to 0(b) of the needle (9) as a function of the stroke (p) of the piston (8):

[0161] (c) > ((m)+(j)+(p))-(d).

[0162] *the dimension (h) of the translational guidance of the needle is: (h)=0.8x0(e).

[0163] *The depth dimension of 0(e) is (j)+(k), (j)+(k) > (c)+(d)+(h)-(m).

[0164] In the case of this chain of dimension and a length (c) of transition of the needle in linear cone we have a different compression and relaxation rolling at each point of the rod stroke (4).

[0165] 7) Device according to paragraph 6, is characterized in that the shape of the needle influences the operation of the suspension, The transition from 0(a) to 0(b) is conical for the example but can also be convex, concave, stepped in operation, cycloidal, have a constant 0(a) over part of the length (c) and an evolution to be chosen from the previous list to arrive at the diameter (b). A reduction of the final diameter towards 0(b) is possible on the rebound circuit to allow a rapid return despite the mass inertias of the system. The different possibilities of shapes serve to best adapt the shock absorber to the application. The length (d) is functional, it is greater than or equal to the travel of the piston (8), see dimension (p) figure (4).

[0166] 8) Device according to paragraph 6, is characterized in that the needle (9) can be equipped with a functional rib placement adjustment (c) in the channel (2) at At the level of its restriction section, we can separate the needle in two in a plane perpendicular to the axis on the length (d) and add a helical connection between the two parts of the needle in order to modify the length (d). The end of 0(b) of the needle would come out of the shock absorber in a sealed manner to allow the displacement of the length (c) relative to the rolling channel by manual rotation of the end of 0(b) the accessible needle. The part of length (d) would be in sliding connection. This adjustment can adapt the proportional rolling to different spring hardnesses.

[0167] 9) Device according to paragraph 6, characterized in that the channel (2) can be divided in two in the shock absorber head (10), this channel (2) going from the barrel (5) to the gas accumulator would start with a drilling to continue on a junction opening onto two parallel drillings, the first identical to paragraphs 4 and 6 would be equipped with the proportional rolling system and the second would be equipped with a non-return valve which would also open into the gas accumulator, see figure (12) diagram 140, this valve would be used to block the expansion flow and authorize, according to a threshold, the compression flow, this addition would allow management of compression overloads and fully controlled expansion according to the configuration of the terrain.

[0168] 10) Device according to paragraph 6, characterized in that the channel (2) can be divided in two in the shock absorber head (10), this channel (2) going from the barrel (5) to the gas accumulator would start with a drilling to continue on a junction opening onto two parallel drillings, the first identical to paragraphs 4 and 6 would be equipped with the proportional rolling system with a non-return valve in series authorizing the expansion flow and blocking the compression flow and the second would be equipped with a non-return valve which would also open into the gas accumulator, see figure (11) diagram 130, this valve would be used to block the expansion flow and authorize the compression flow, this addition would allow strict management of the compression in a conventional manner and a fully controlled expansion according to the configuration of the terrain.

[0169] 11) Device according to paragraph 6, characterized in that the channel (2) can be divided in two in the shock absorber head (10), this channel (2) going from the barrel (5) to the gas accumulator would start with a drilling to continue on a junction opening on two parallel drillings, these two drillings would open off-center and parallel to the axis of the piston (8) in the gas accumulator (6). The piston would be equipped with two different needles (9), off-center, coaxial with the two drillings of the channel (2) respecting paragraphs 3 and 6. The first drilling identical to paragraphs 4 and 6 would be equipped with the proportional throttling system with a non-return valve in series authorizing the expansion flow and blocking the compression flow and the second drilling would comply with paragraphs 4 and 6, it would be equipped with a proportional throttling system and a non-return valve in series which would also open in the gas accumulator, see figure (9) diagram 110, this valve would be used to block the expansion flow and allow compression flow, this addition would allow strict and differentiated management of compression and expansion depending on the terrain configurations.

[0170] 12) Device according to paragraph 6, characterized in that the channel (2) can be divided in three in the shock absorber head (10), this channel (2) going from the barrel (5) to the gas accumulator would start with a drilling to continue on a junction opening onto three parallel drillings, the three drillings would open off-center and parallel to the axis of the piston (8) in the gas accumulator (6). The piston would be equipped with two different needles (9), off-center, coaxial with two drillings of the channel (2) respecting paragraphs 3 and 6.The first bore identical to paragraphs 4 and 6 would be equipped with the proportional throttling system with a non-return valve in series allowing the expansion flow and blocking the compression flow, the second bore would comply with paragraphs 4 and 6, it would be equipped with a proportional throttling system and a non-return valve in series which would also open into the gas accumulator, see figure (10) diagram 120, this valve would be used to block the expansion flow and allow the compression flow, the third channel would be equipped with a non-return valve with a trigger threshold blocking the expansion flow and allowing the compression flow. This addition would allow strict and differentiated management of compression and expansion and the management of compression overloads to adapt to different applications.

Claims

Claims

1. The proportional throttling shock absorber device, operates with forks or shock absorbers equipped with a separate gas accumulator, characterized in that the proportional throttling shock absorber, comprises a rod volume compensation piston (3) which is replaced by a new assembly (7) consisting of the piston (8) and the needle (9), the needle (9) is fixed in a sealed manner on the piston, its main axis is concentric with the axis of movement of the piston (8), and the rod volume compensation channel (2) is designed so that the needle (9) can move in the axis of the channel (2).

2. Device according to claim 1, characterized in that the needle (9) is provided with a variable shape over its length, at the level of the attachment with the piston (8), its diameter (a), less than the diameter of the piston, remains constant over the length (d), it then evolves over the length (c) up to a diameter (b), the diameter (a) is less than the diameter (b), its last length (h), at its top, is an adjusted translation guide of diameter (b) with its height (h) equal to 0.8 times the diameter (b), it has two flats at the end to allow the oil from the bottom of the channel (2) to circulate, the height of these flats is greater than the height (h) and disappear over a small part of the length (d), the depth of these flats is 0.25 times the diameter (b).

3. Device according to claim 2 characterized in that the hydraulic channel (2) connecting the main barrel (5) to the gas reservoir (6) is made up of two bores, the first starts with a diameter (g) from the top of the rolling barrel (5), in the area opposite the rod (4) and not occupied by the main rolling piston (34) when the shock absorber is fully compressed, this bore of diameter (g) starts radially towards the operating axis of the rod volume compensation piston (8), it opens perpendicularly onto the second bore of the channel (2) of diameter (e) which starts from the top of the gas reservoir (6) concentric with the axis of the needle (9) fixed on the piston (8), this bore of diameter (e) passes in the axis of the first bore of diameter (g) at the height (j), it is of total depth (j) plus (k),the opening caused by drilling diameter (e) into drilling diameter (g) at height (j) minus times diameter (g) is the restriction section, the, restriction plane of the channel (2) is the plane perpendicular to the diameter axis (e), parallel to the diameter axis (g) at the height (j) minus F? times the diameter (g), the restriction section is in the restriction plane.

4. Device according to claim 3 characterized in that the diameter (e) is dimensioned so that the diameter section (a) of the needle (9) coaxial with the diameter (e) located in the restriction plane of the channel (2) leaves a passage section equivalent to the diameter section (g) which brings the rod volume compensation oil when the shock absorber is relaxed, The diameter area (g) is less than or equal ( < ) to the diameter area (e) minus the diameter area (a), when the diameter (a) of the needle is at the height of the restriction plane in the diameter (e) of the channel (2) there is at least conservation of the diameter section (g) over the entire length of the channel (2).

5. Device according to claim 2, characterized in that the maximum displacement of the piston (8) corresponds to the length (p) induced by the total compression of the shock absorber, the needle therefore moves by a height (p) in the channel (2), the needle will therefore have a strictly proportional placement in relation to the retraction of the rod.

6. Device according to claims 4 and 5 taken in combination, characterized in that the compressed damper induces that the needle (9) moves by the height (p) in the channel (2) and places its section of diameter (n) in the restriction section, with diameter (n) greater (>) than the diameter (a), therefore the restriction section is equal to diameter (e) minus diameter (n) with diameter (a) less (<) than the diameter (n) less than the diameter (b), when the damper is fully compressed it moves the needle (9) by a height (p) and places the section of diameter (n) in the restriction section of the channel (2), the diameter (n) is greater than the diameter (a) and reduces the passage of the restriction section.

7. Device according to claim 6, characterized in that the needle can have different shapes, The transition from diameter (a) to diameter (b) is conical for the example but can also be convex, concave, stepped in step, cycloidal, have a constant diameter (a) over a part of the length (c) and an evolution to be chosen from the previous list to arrive at diameter (b), a reduction of the final diameter before diameter (b) is possible on the expansion circuit, The length (d) is functional, it is greater than or equal to the travel of the piston (8) equal to the dimension (p).

8. Device according to claim 6, characterized in that the needle (9) is equipped with an adjustment for placing the functional dimension (c) in the channel (2) at its restriction section, the needle is separated in two in a plane perpendicular to the axis over the length (d) and comprises a helical connection between the two parts of the needle in order to modify the length (d), the end of diameter (b) of the needle leaves the damper in a sealed manner in a sliding connection to allow its manual rotation and the displacement of the length (c) relative to the rolling channel.

9. Device according to claim 6, characterized in that the channel (2) is divided into two in the shock absorber head (10), this channel (2) goes from the barrel (5) to the gas accumulator, starts with a bore to continue on a junction opening onto two parallel bores, the first channel and its needle are in accordance with claims 1 to 8 with the proportional rolling system, the second channel is equipped with a non-return valve which blocks the expansion flow and authorizes, according to a threshold, the compression flow, it opens into the gas accumulator (6).

10. Device according to claim 6, characterized in that the channel (2) is divided into two in the shock absorber head (10), this channel (2) goes from the barrel (5) to the gas accumulator, leaves with a bore to continue on a junction which opens onto two parallel bores, the first channel and its needle are in accordance with claims 1 to 8 with the proportional rolling system and a non-return valve in series allowing the expansion flow and blocking the compression flow, the second circuit is equipped with a non-return valve which serves to block the expansion flow and allow the compression flow, it opens into the gas accumulator (6).

11. Device according to claim 6, characterized in that the channel (2) is divided into two in the shock absorber head (10), the channel (2) goes from the barrel (5) to the gas accumulator (6), it starts with a bore to continue on a junction which opens onto two parallel bores, these two bores open off-center and parallel to the axis of the piston (8) in the gas accumulator (6), the piston is equipped with two different needles (9), off-center, coaxial with the two bores of the channel (2), the first bore and its needle

12. comply with claims 1 to 8 with the proportional throttling system and a non-return valve in series which allows the expansion flow and blocks the compression flow, the second bore and its needle comply with claims 1 to 8 with the proportional throttling system and a non-return valve in series which blocks the expansion flow and allows the compression flow, it opens into the gas accumulator. Device according to claim 6, characterized in that the channel (2) is divided into three in the shock absorber head (10), the channel (2) goes from the barrel (5) to the gas accumulator (6), it starts with a bore to continue on a junction opening onto three parallel bores, the three bores open off-center and parallel to the axis of the piston (8) in the gas accumulator (6), the piston is equipped with two different needles (9), off-center, coaxial with the two bores of the channel (2), the first bore and its needle are in accordance with claims 1 to 8 with the proportional throttling system and a non-return valve in series which allows the expansion flow and blocks the compression flow, the second bore and its needle are in accordance with claims 1 to 8 with the proportional throttling system and a non-return valve in series which serves to block the expansion flow and allow the compression flow,the third channel is equipped with a non-return valve with a trigger threshold which blocks the expansion flow and allows the compression flow.

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