Height-adjustable damper assembly

Abstract

A height adjustable shock absorber assembly (1) for two wheeled motor vehicles and the like, comprising a shock absorber (2, 102) having a spring (3), for example a coil spring coaxial with the shock absorber (2, 102), the shock absorber (2, 102) having a nominal length (L) and at least two shafts (8, 9) operatively connected with the vehicle suspension, the spring (3) having a first end (4) and a second end (5); at least one hydraulic fluid push rod (6) mounted in series with the spring (3), the push rod (6) acting on either end (4, 5) of the spring (3) or on either shaft (8, 9); and a source (7) of pressurized hydraulic fluid in fluid connection with the push rod (6) for actuating the push rod (6), the shock absorber assembly (1) comprising an accumulator tank assembly (27) in fluid connection with the push rod (6), which in turn comprises a tank (28) and a solenoid valve (31) controlling the opening or closing of an inlet / outlet port of the hydraulic fluid of the tank (28) so as to allow a rapid discharge of the hydraulic fluid present in the push rod (6) to the tank (28) and thus an immediate release of the pre-load of the spring (3) of the shock absorber (2) or an immediate reduction of the load length of the shock absorber (102) and hence an immediate lowering of the vehicle.

Description

Technical Field

[0001] This invention relates to a height-adjustable shock absorber assembly, particularly to a shock absorber assembly that allows for rapid lowering of a vehicle, applicable to two-wheeled motor vehicles, i.e., sidecars or tilting light vehicles with three or four wheels, and more broadly to any type of motor vehicle equipped with a height-adjustable suspension. Background Technology

[0002] In the realm of two-wheeled vehicles, there is a growing need to adjust seat height according to usage conditions and load. Some current two-wheeled vehicles, such as motorcycles in endurance racing or so-called crossovers, require a fairly high stance for off-road use, but this contradicts the requirement for easy vehicle control at all low speeds (where the driver's feet need to be on the ground).

[0003] To meet these needs, the latest generation of motorcycles in the endurance / cross-country racing field are almost all equipped with suspension adjustment devices to compensate for the load and allow for personalized seat height adjustments.

[0004] Therefore, depending on the complexity of the control systems present in the vehicle, suspension adjustment is used more or less in a dynamic manner.

[0005] In known types of electro-hydraulic operating adjustment devices, in order to obtain faster suspension adjustment time, it is necessary to increase the power of the drive motor of the hydraulic pump. However, this violates the power limitations available on two-wheeled vehicles or similar vehicles (e.g., motorcycles).

[0006] Due to these power requirements, the actuation speed of the seat lifting system is strictly limited by the vehicle's electrical power; similarly, the speed during descent is also limited.

[0007] Documents EP3024675A1 and WO2008 / 038321A1 describe a height-adjustable shock absorber using an electro-hydraulic device. The shock absorber includes a pushrod unit acting on a spring to increase or decrease the spring preload of the shock absorber, thereby changing the height of the vehicle on which the shock absorber is mounted. Alternatively, the pushrod unit acts on one end of the shock absorber in one of the shock absorber couplings near the vehicle to directly increase or decrease the length of the shock absorber. An electro-hydraulic pump is also provided to feed oil to the pushrod unit under pressure.

[0008] In the device shown in EP3024675A1, the push rod unit is single-acting, and the hydraulic pump can be either double-acting or single-acting. In the device shown in WO2008 / 038321A1, the push rod unit is double-acting for conveying oil and is equipped with a pressurized oil reservoir that is periodically filled by a single-acting pump to draw oil from a low-pressure tank.

[0009] Due to the power limitations of the pump motor and / or the hydraulic components used, devices of the type described above are particularly incapable of rapidly lowering vehicles, in addition to being relatively complex.

[0010] In fact, for double-acting hydraulic pumps, the electric power of the motor driving the pump is insufficient to make the push rod unit move quickly. For single-acting hydraulic pumps, when used to discharge oil from the push rod unit, the oil ports of the two-way and two-position solenoid valves are relatively small and do not allow for a large oil flow rate, which actually creates a bottleneck that blocks the oil flow rate.

[0011] It should be considered that the ideal choice, especially during the lowering process, is that the complete displacement time of the push rod assembly can be measured in tenths of a second, while for the device described above, the displacement time of the push rod assembly is approximately ten seconds.

[0012] Documents US5181696A, US2014 / 0077465A1, and EP3225527A1 describe a height-adjustable shock absorber that uses a pump element provided by the suspension itself to obtain pressurized fluid for vehicle height adjustment.

[0013] Therefore, in order to achieve the fluid pressure required for vehicle height adjustment, the vehicle's suspension needs to vibrate a certain number of times. Thus, height adjustment is not immediate and may even take a relatively long time. Document DEI02014207055A1 describes a suspension system for a vehicle that includes a mechanical spring and a hydraulic-pneumatic spring. The hydraulic-pneumatic spring has a hydraulic volume that can be adjusted via a pneumatic container element. To lower the suspension, the volume of the hydraulic-pneumatic spring is emptied through a blocking valve. This results in a considerably long emptying time for the hydraulic-pneumatic spring, which in turn leads to a similarly long suspension lowering time. Summary of the Invention

[0014] The technical scope of this invention is to improve the technical state of height-adjustable vibration dampers.

[0015] Another object of the present invention is to manufacture a height-adjustable shock absorber assembly that has a shorter vehicle lowering time than known solutions. Another object of the present invention is to manufacture a height-adjustable shock absorber assembly that can be easily installed in a vehicle with very little available space, particularly in the case of two-wheeled motor vehicles.

[0016] Another object of the present invention is to provide a height-adjustable damper assembly made of lightweight and low-cost components.

[0017] Another object of the present invention is to provide a height-adjustable vibration damper assembly that requires lower electrical power to operate during lowering. According to one aspect of the invention, a height-adjustable vibration damper assembly as described in claim 1 is provided.

[0018] According to another aspect of the invention, a kit for updating or retrofitting height-adjustable shock absorbers, as described in technical solution 8, is proposed.

[0019] According to another aspect of the present invention, a method for operating a height-adjustable vibration damper is provided according to technical solution 9.

[0020] The dependent technical solutions relate to preferred and advantageous embodiments of the present invention. Attached Figure Description

[0021] Other features and advantages of the invention will become clearer from the following detailed description of some exemplary embodiments thereof, which are shown in the accompanying drawings as examples only and not as limiting descriptions, wherein:

[0022] Figure 1 This is a schematic front view of a height-adjustable damper assembly according to the present invention.

[0023] Figure 2 yes Figure 1 A cross-sectional view showing some details of the height-adjustable shock absorber assembly mentioned in the text.

[0024] Figure 3 yes Figure 1 Another detailed cross-sectional view of the height-adjustable shock absorber assembly involved.

[0025] Figure 4 This is a schematic front view of another type of height-adjustable damper assembly according to the present invention.

[0026] Figure 5 This is a schematic front view of yet another type of height-adjustable damper assembly according to the present invention. Detailed Implementation

[0027] Referring to one embodiment of the present invention, Figure 1 A height-adjustable shock absorber assembly is shown, and is indicated by 1 for its entirety. This shock absorber assembly can be mounted on a two-wheeled vehicle (not shown), a sidecar, or a tilting light vehicle with three or four wheels. Figure 1In the illustrated type, the height-adjustable damper assembly 1 mainly includes: a damper 2 having at least one spring 3, such as a helical spring coaxial with the damper 2, the spring 3 having a first end 4 and a second end 5; at least one hydraulic fluid type push rod 6, the push rod 6 also coaxial with the damper 2 and connected in series with the spring 3, the push rod 6 acting on either of the two ends 4 and 5 of the spring 3; and a pressurized hydraulic fluid source 7, the source 7 actuating the push rod 6.

[0028] It should be noted that the height-adjustable shock absorber assembly according to the invention can also be applied to different types of suspensions, such as telescopic forks for motorcycles. In this case, the pushrod can be mounted in series with each spring inside the outer tube of the fork. However, the pushrod does not always need to be coaxial with the shock absorber. Therefore, the pushrod can also be configured as an actuator containing a standard hydraulic cylinder, i.e., a non-annular single-acting type.

[0029] The shock absorber 2 has a nominal length L and includes at least two couplings 8 and 9 that are operably connected to the vehicle suspension.

[0030] The damper 2 also has a first support base 10 located at a first support position P1 and a second support base 11 located at a second support position P2; the first end 4 of the spring 3 rests on the first support base 10 of the damper 2 at the first position P1, and the second end 5 rests on the second support base 11 of the damper 2 at the second position P2.

[0031] Push rod 6 can change the support position P1 or P2 of one of the ends 4 or 5 of spring 3; especially in Figure 1 In this configuration, the push rod assembly 6 is positioned to contact and act on the first end 4 of the spring 3, thereby changing the first support position P1 of the first end 4 of the spring 3.

[0032] It should be noted that, alternatively, the push rod 6 can contact and act on the second end 5 of the spring 3 by changing the second position P2 of the second end 5 of the spring 3; if possible, two push rods 6 can be provided to change the two support positions P1 and P2 of the spring 3.

[0033] By changing the support position P1, or the support position P2, or both support positions P1 and P2, the preload of spring 3 is changed: the initial preload can be increased, or the initial preload can be decreased or canceled.

[0034] Therefore, the height of the shock absorber assembly 1 can be changed, and more broadly, the height of the vehicle equipped with the aforementioned shock absorber assembly 1 can be changed: by increasing the preload of the spring 3, the height of the vehicle will actually increase because the vehicle's own weight and the load applied to the vehicle will reduce the suspension's sinking under load; by decreasing (or canceling) the preload of the spring 3, the height of the vehicle will actually decrease because the suspension's sinking under load will increase.

[0035] The push rod 6 includes a hydraulic actuator driven by a pressurized hydraulic fluid source 7; in Figure 1 and Figure 2 In this configuration, the hydraulic actuator is configured as an annular cylinder 12 connected in series with the spring 3.

[0036] The assembly including spring 3 and cylinder 12 can replace the ordinary spring of the shock absorber without adjustment. Therefore, the shock absorber assembly 1 according to the invention can also be regarded as or sold as an upgrade or modification of existing shock absorbers without height adjustment.

[0037] Similarly, in the case of a telescopic fork for a motorcycle, the spring and push rod assembly according to the invention can replace the ordinary springs provided in each slider of a pre-existing fork, thereby constituting an update or modification of the pre-existing telescopic fork.

[0038] Obviously, the height-adjustable shock absorber assembly according to the invention can also be used as original equipment for newly manufactured vehicles.

[0039] Figure 2 The cylinder 12 is shown in cross section. The cylinder 12 includes a sleeve 13, a hollow portion 14 fixed to the sleeve 13, and a piston 15 sliding in a sealed manner within the hollow portion 14. Thus, by replacing a portion of the previous spring, the cylinder 12 can be inserted into a pre-existing shock absorber, wherein the inner diameter of the sleeve 13 must correspond to the outer diameter of the pre-existing shock absorber.

[0040] The pressurized hydraulic fluid source 7 is directly connected to the push rod 6 through the pipe 16, without any intermediate valve.

[0041] Pipe 16 is in fluid communication with cylinder 12 of push rod 6; for this purpose, pipe 16 is fixed to hydraulic connector 18 which communicates with the inner cavity of cylinder 12.

[0042] It should be noted that, due to the direct connection between the pressurized hydraulic fluid source 7 and the push rod 6, the damper assembly 1 according to the invention is simpler, lighter, cheaper, and more reliable than known solutions that include more than one solenoid valve.

[0043] As described above, cylinder 12 is a single-acting cylinder that is actively actuated by hydraulic fluid and is used only to increase the preload of spring 3. When the preload of spring 3 must be reduced or canceled when the vehicle is lowered, it is the aforementioned spring 3 that pushes the piston 15 of the cylinder itself to vent the hydraulic fluid from the inner cavity of cylinder 12.

[0044] Since cylinder 12 is a single-acting type, its structure is particularly simple, lightweight, reliable, and has low production cost.

[0045] The hydraulic fluid source 7 includes a hydraulic pump 19 driven by an electric motor unit 20.

[0046] Hydraulic pump 19 includes a single-acting hydraulic cylinder with piston 21 (see...) Figure 2 The piston 21 slides in a sealed manner within the hydraulic cylinder and moves linearly in two directions within the stroke limit of the same piston 21 via the electric motor assembly 20.

[0047] Therefore, the hydraulic pump 19 implemented in this way is simple, lightweight, reliable, and has low manufacturing cost.

[0048] according to Figure 2 As shown, the aforementioned motor assembly 20 includes: a rotary motor 22; a possible reduction unit 23, such as a planetary gear reduction unit; and a mechanism 24 for converting the rotary motion of the motor 22 into linear motion, which in turn moves the piston 21, and also provides an electrical connection 25 for the motor 22.

[0049] The aforementioned structural form, comprising a rotary electric motor 22, a possible reduction unit 23 (e.g., a planetary gear reduction unit), and a mechanism 24 for converting the rotary motion of the motor 22 into linear motion, allows for the use of a small and lightweight electric motor while maintaining the same power output and utilizing a limited floor space. The mechanism 24 for converting the rotary motion into linear motion can be implemented in various ways, such as with gears meshing on a rack, a thrust crank mechanism, a cam and a follower, and particularly with a mechanism formed by screws 25 and nuts 26 operably connected to each other.

[0050] like Figure 2 As shown, it can be noted that screw 25 is connected to motor 22, while nut screw 26 is connected to piston 21. Of course, these components 25 and 26 can be interchanged.

[0051] Therefore, a direct connection is achieved between the pump 19 and the hydraulic cylinder 12, similar to the hydraulic drive device of a motor vehicle's brake or clutch.

[0052] In this way, by controlling the rotation of the screw 25 of the motor assembly 20, the output of the piston 21 of the cylinder 12 can be positioned in millimeter increments; as described above, actuation occurs in one direction and another within the range set by the stroke of the piston 21.

[0053] An important feature of the present invention is that the height-adjustable shock absorber assembly 1 includes an energy storage tank assembly 27, which is fluidly connected to the cylinder 12 of the push rod 6 via a second pipe 17 of a hydraulic connector 18 fixed to the cylinder 12.

[0054] The accumulator assembly 27 further includes: at least one cylinder 28; at least one low-pressure accumulator chamber 29, which may consist of a device having a gas-filled membrane 30 or a device having a hydraulic fluid separator and a mechanical spring (not shown); and at least one solenoid valve 31, which is present in two positions and controls the opening or closing of the hydraulic fluid inlet / outlet port. By opening the solenoid valve 31, the accumulator assembly 27 allows for the rapid release of any pressure present in the push rod 6, thereby immediately releasing the spring preload of the shock absorber, thereby lowering the vehicle.

[0055] The solenoid valve 31 is configured to include a port with a large cross-section to reduce the pressure drop of the hydraulic fluid, thereby providing low resistance to the discharge of hydraulic fluid in the cylinder 12 of the push rod 6, enabling the vehicle to lower rapidly.

[0056] With solenoid valve 31 closed, the shock absorber assembly 1 will operate in a normal manner because the hydraulic fluid present in the circuit is entirely contained in the hydraulic lines, which include the hydraulic pump 19, pipe 16 and cylinder 12 of push rod 6.

[0057] In this way, the preload of spring 3 can be adjusted, thereby adjusting the vehicle height under load with very precise positioning control.

[0058] When it is suddenly necessary to lower the vehicle from any height position of the vehicle, for example from any preload position of the spring 3 that is greater than the minimum preload condition of the spring 3, the solenoid valve 31 is opened to allow hydraulic fluid to be rapidly discharged from the cylinder 12 of the pushrod assembly 6 to the accumulator assembly 27, thereby moving the support position P1 or P2 of the spring 3 in order to shorten the load length of the shock absorber 2.

[0059] At this time, that is, after the aforementioned rapid discharge of hydraulic fluid, while keeping the solenoid valve 31 open, the hydraulic pump 19 draws the hydraulic fluid out of the cylinder assembly 27 and returns it to the position where the piston 21 determines the minimum preload, that is, the piston 21 is pulled back, and draws the hydraulic fluid out of the cylinder assembly 27 to the main circuit consisting of the cylinder 12 of the same hydraulic pump 19, pipe 16 and push rod 6.

[0060] The emptying of the accumulator tank 28 is also accomplished with the help of the pressure in the accumulator chamber 29, but the aforementioned pressure cannot be too high, because it must allow the cylinder 12 of the push rod 6 to be completely discharged. Usually, the pressure in the accumulator chamber 29 is between 2 and 4 bar, that is, 0.2-0.4 MPa.

[0061] When the hydraulic pump 19 returns to its minimum preload position, the solenoid valve 31 closes, and the damper assembly 1 prepares for another operating cycle. Figure 4 The second embodiment of the invention shown has a shock absorber 102 equipped with a push rod 6 and includes a hydraulic cylinder 12 having a displacement stroke C. The push rod 6 is located at either end of the shock absorber 102, where the couplings 8 and 9 connecting the shock absorber 102 to the vehicle suspension are located.

[0062] The other components of the height-adjustable shock absorber assembly 1 of this type are the same as those of the previous type and will not be described further. The effect of introducing hydraulic fluid into or draining hydraulic fluid from the hydraulic cylinder 12 is that the stroke C of the hydraulic cylinder 12 can be adjusted, thereby directly adjusting the load length of the shock absorber 102, instead of adjusting the preload of the spring 3 as in the previous type.

[0063] The effect and operation of this type of height-adjustable shock absorber assembly 1 are very similar to the previous type: by operating the push rod 6, the length of the shock absorber 102 increases due to the stroke C of the hydraulic cylinder 12, and thus the height of the vehicle increases, even though the shock absorber 102 is usually under load. Therefore, the length of the shock absorber 102 is shorter than the nominal length L.

[0064] Of course, by reducing (or setting to zero) the available stroke C of the hydraulic cylinder 12, the height of the vehicle will also be reduced because the length of the shock absorber 102 under load will be reduced.

[0065] according to Figure 5 In the third embodiment of the invention shown, the energy storage tank assembly 27 is integrated into the pressurized hydraulic fluid source 7, that is, the energy storage tank assembly 27, the hydraulic pump 19 and the motor assembly 20 constitute a single unit. The length of the second pipe 17 is much shorter, or it can be completely eliminated, because the energy storage tank assembly 27 is very close to the outlet of the hydraulic pump 19 or is integrated with the hydraulic pump 19.

[0066] In the third embodiment of the invention, the integration of components 7 and 27 can reduce weight to some extent and allow these components to be installed on the vehicle more quickly, while in the first embodiment of the invention, the separation of components 7 and 27 can help to find available space on the vehicle, since these components can be placed in different locations.

[0067] Similarly, for this third type, other components, particularly the damper 2, remain the same as in the first type of the invention; alternatively, the damper 102 of the second type as described above can also be used.

[0068] Thus, it can be seen how the present invention achieves its intended purpose. Various modifications and variations can be made to the present invention without departing from its scope.

[0069] Furthermore, all components can be replaced with other technically equivalent components.

[0070] In fact, without departing from the scope of the following claims, the materials used, as well as the corresponding dimensions and shapes, can vary considerably as needed.

Claims

1. A shock absorber assembly (1), the height of which is adjustable and is intended for two-wheeled motor vehicles, or for saddle-type or tilting light vehicles with three or four wheels, comprising: Shock absorber (2, 102) having at least one spring (3), said shock absorber (2, 102) having a nominal length (L) and at least two joints (8, 9) operatively connected to the suspension of a vehicle, said spring (3) having a first end (4) and a second end (5); at least one push rod (6) of hydraulic fluid mounted in series with said spring (3), said push rod (6) acting on either of said first end (4) and said second end (5) of said spring (3) or said push rod (6) acting on either of said two joints (8, 9); and a source (7) of pressurized hydraulic fluid fluidically connected to said push rod (6) and actuating said push rod (6), characterized in that said source (7) of pressurized hydraulic fluid is directly fluidically connected to said push rod (6) by a duct, without the presence of an intermediate valve between said source (7) of pressurized hydraulic fluid and said push rod (6), wherein said duct in turn fluidically communicates with the cylinder of said push rod, and wherein said duct is fixed to a hydraulic connection communicating with the internal cavity of said cylinder, and said shock absorber assembly comprises an accumulator tank assembly (27) fluidically connected to the internal cavity of said cylinder of said push rod (6) by a second duct fixed to said hydraulic connection of said cylinder, said accumulator tank assembly (27) in turn comprising at least one tank (28) and at least one solenoid valve (31) controlling the opening or closing of the inlet / outlet port of the hydraulic fluid of said tank (28), said solenoid valve (31) being provided with a port of large section and reducing the pressure drop of the hydraulic fluid, so as to allow the rapid discharge of the hydraulic fluid present in said push rod (6) towards said tank (28) and the immediate release of the pre-load of said spring (3) of said shock absorber (2) or the immediate reduction of the load length of said shock absorber (102), thereby immediately reducing the vehicle.

2. The shock absorber assembly of claim 1, wherein, Said at least one spring (3) comprises a helical spring coaxial to said shock absorber (2, 102).

3. The shock absorber assembly of claim 1, wherein, Said accumulator tank assembly (27) comprises a device with a membrane (30) loaded with gas or a device with an assembly consisting of a hydraulic fluid separator and a mechanical spring.

4. The shock absorber assembly of claim 1, wherein, Said solenoid valve (31) comprises a port for the hydraulic fluid of relatively large section, so as to provide low resistance to the discharge of the hydraulic fluid located in said push rod (6).

5. The shock absorber assembly of any one of claims 1 to 4, wherein, Said source (7) of pressurized hydraulic fluid comprises a single-acting hydraulic pump (19) driven by an electric motor via an electric motor assembly (20) of the electric motor type.

6. The shock absorber assembly of claim 5, wherein, Said single-acting hydraulic pump (19) comprises a single-acting hydraulic cylinder comprising a piston (21) sliding in a sealed manner inside said hydraulic cylinder and operated in a linear manner in both directions by said electric motor assembly (20) within the stroke limits of said piston (21) itself.

7. The shock absorber assembly of claim 5, wherein, Said electric motor assembly (20) comprises a rotary electric motor (22), a reducer (23) and a mechanism (24) converting the rotary motion of said electric motor (22) into linear motion.

8. The shock absorber assembly of claim 6, wherein, The electric motor assembly (20) comprises: a rotary electric motor (22); a reducer (23); and a mechanism (24) that converts the rotary motion of the electric motor (22) into linear motion.

9. The shock absorber assembly of claim 7 or 8, wherein, The reducer (23) comprises a reducer with planetary gears.

10. The shock absorber assembly of claim 7, wherein, The mechanism (24) that converts rotary motion into linear motion comprises a mechanism formed by a screw (25) and a nut screw (26) operatively connected to each other.

11. A kit for upgrading or retrofitting a height-adjustable shock absorber, comprising a height-adjustable shock absorber assembly (1) as claimed in any one of claims 1-10.

12. A driving method of a height-adjustable shock absorber assembly, comprising the steps of: providing a height-adjustable shock absorber assembly (1) as claimed in any one of claims 1 to 10 for two-wheeled motor vehicles, or for saddle-type vehicles or for tilting light vehicles with three or four wheels; adjusting the pre-load of the spring (3) or the length of the shock absorber (102) in order to adjust the height of the loaded vehicle with precise positioning control; characterized by comprising the steps of: opening the electromagnetic valve (31) to allow the rapid discharge of hydraulic fluid from the cylinder (12) of the push rod (6) to the accumulator tank assembly (27) when it is necessary to suddenly lower the vehicle starting from any height position of the vehicle; maintaining the electromagnetic valve (31) open; and recovering the hydraulic fluid from the accumulator tank assembly (27) to the pressurized hydraulic fluid source (7) and to the push rod (6), bringing the pressurized hydraulic fluid source (7) back to the minimum pre-load position of the spring (3) or to the minimum length of the shock absorber (102).

13. The method of driving a height adjustable shock absorber assembly of claim 12, wherein, The steps are performed in the order described in claim 12 and comprise the subsequent step of closing the electromagnetic valve (31) in order to prepare the height-adjustable shock absorber assembly for a new operating cycle.

14. A method of driving a height adjustable damper assembly according to claim 12 or 13, characterized in that The pressurized hydraulic fluid source (7) comprises a single-acting hydraulic cylinder having a piston (21) sliding in a sealed manner inside the single-acting hydraulic cylinder and actuated in linear manner in both directions by the electric motor assembly (20) within the stroke limits of the piston (21).

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