Shock Absorber Assembly with Adjustable Height

Abstract

A shock absorber assembly (1) having an adjustable height for a two-wheel power vehicle or the like, comprising a spring (3), for example a shock absorber (2, 102) with a helical spring coaxial with the shock absorber (2, 102), the shock absorber (2, 102) having a nominal length (L), and at least two couplings (8, 9) operatively connected to a suspension of the vehicle, the spring (3) having a first end (4) and a second end (5), the shock absorber assembly (1) comprising at least one hydraulic fluid pusher (6) mounted in series with the spring (3) and acting on either end (4, 5) of the spring (3) or on either coupling (8, 9), and a source of pressurized hydraulic fluid (7) fluidly connected to the pusher (6) for actuating the pusher (6), and the shock absorber assembly (1) comprises an accumulator tank assembly (27) fluidly connected to the pusher (6), the accumulator tank assembly (27) having a tank (28) and a solenoid valve (31) for controlling the opening and closing of hydraulic fluid inlet / outlet openings in the tank (28), allowing for the rapid discharge of hydraulic fluid present in the pusher (6) into the tank (28), thereby allowing for the immediate release of preload by the spring (3) of the shock absorber (2) or the immediate reduction of the loaded length of the shock absorber (102), and therefore the occurrence of an immediate lowering of the vehicle.

Description

Technical Field

[0001] The present invention relates to a shock absorber assembly having an adjustable height, and more particularly to the field of two-wheeled vehicles and the like, i.e., sidecars or three- or four-wheeled lightweight vehicles of the type that tilt at corners, and to a shock absorber assembly that enables rapid descent of a vehicle that can be used in such vehicles. More generally, it can also refer to any type of powered vehicle equipped with a height-adjustable suspension.

Background Art

[0002] In the field of two-wheeled vehicles and the like, there is an increasing need to adjust the seat height according to usage conditions and load conditions. Some current two-wheeled vehicles, such as motorcycles in the long-distance endurance segment or so-called crossover vehicles, require a somewhat high stance to handle the vehicle off-road, but at the same time, it is contrary to the need to be able to easily handle the vehicle in all low-speed situations where the driver needs to put their feet on the ground.

[0003] To meet these needs, almost all new-generation motorcycles in the long-distance endurance / crossover segment are equipped with a suspension adjustment device that compensates for the vehicle load and enables personalized adjustment of the seat height.

[0004] Therefore, suspension adjustment is used somewhat dynamically based on the level of complexity of the control system present in the vehicle.

[0005] In known types of electro-hydraulic actuated adjustment devices, in order to obtain a faster suspension adjustment time, it is necessary to increase the power in the drive motor of the hydraulic pump, which is contrary to the power limits available in two-wheeled vehicles such as motorcycles.

[0006] Due to this power requirement, the operating speed of the seat raising system is strictly limited by the vehicle's power, and similarly, the speed during descent is also limited.

[0007] Patent Document 1 (European Patent Publication No. 3024675) and Patent Document 2 (International Publication No. 2008 / 038321) disclose an electro-hydraulic device that includes a pusher unit acting on a spring, increases or decreases the spring preload of a shock absorber, and thus changes the height of a vehicle equipped with the shock absorber, or the pusher unit acts on one end of the shock absorber near one joint of the vehicle's shock absorber to directly increase or decrease the length of the shock absorber, and an electro-hydraulic pump for supplying pressurized oil to the pusher unit is provided, for a shock absorber with adjustable height.

[0008] In the device described in Patent Document 1, the pusher unit is of a single-acting type, and the hydraulic pump can be of a double-acting or single-acting type. While in the device described in Patent Document 2, the pusher unit is of a double-acting type, and a pressurized oil accumulator filled at regular intervals by a single-acting pump that takes in oil from a low-pressure tank is provided for oil feeding.

[0009] In addition to being relatively complex, the devices of the above-described type cannot rapidly lower the vehicle especially because the power of the pump motor and / or hydraulic components used is limited.

[0010] In fact, in the case of a double-acting hydraulic pump, the power of the motor driving the pump is not high enough to enable rapid movement of the pusher unit. Also, in the case of a single-acting hydraulic pump, the two-way and two-position solenoid valve has a relatively small oil port when used to drain oil from the pusher unit, does not allow a large flow rate, and actually creates a bottleneck that restricts the oil flow in reality.

[0011] In particular, the ideal option is to have a total displacement time of the pusher assembly that can be measured at about 1 / 10 of a second during descent. However, considering the above-described device, the displacement time of the pusher assembly is about 10 seconds and should be taken into account.

[0012] Patent Document 3 (U.S. Patent No. 5,181,696), Patent Document 4 (U.S. Published Patent Application No. 2014 / 0077465), and Patent Document 5 (European Patent Publication No. 3225527) describe a height-adjustable shock absorber that uses a pumping element provided in the suspension itself to obtain pressurized fluid for vehicle height adjustment.

[0013] In order to achieve the pressure of the fluid required for vehicle height adjustment, the vehicle's suspension needs to perform a predetermined number of vibrations. As a result, the height adjustment is not immediate and may require a relatively long time.

[0014] Patent Document 6 (German Patent Publication No. 102014207055) describes a vehicle suspension system having a mechanical spring and a hydropneumatic spring having a hydraulic volume that can be adjusted by a pneumatic container element to lower the suspension. The volume of the hydropneumatic spring is emptied by a choke valve, and as a result, the time to empty the volume of the hydropneumatic spring becomes several minutes long, and accordingly, the suspension lowering time also becomes long.

Prior Art Documents

Patent Documents

[0015]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0016] The technical scope of the present invention is to improve the state of the art in the field of height-adjustable shock absorbers.

[0017] Another object of the present invention is to create a shock absorber assembly with an adjustable height that has a shorter vehicle lowering time than known solutions.

[0018] Another object of the present invention is to create a shock absorber assembly with an adjustable height that can be easily installed in a limited space, particularly in a two-wheeled vehicle or the like, as the case may be.

[0019] Yet another object of the present invention is to obtain a height-adjustable shock absorber made of lightweight and low-cost components.

[0020] Another object of the present invention is to obtain a height-adjustable shock absorber assembly that operates with low power during the lowering phase.

Means for Solving the Problems

[0021] According to one aspect of the present invention, a shock absorber assembly having an adjustable height according to claim 1 of the claims is proposed.

[0022] According to another aspect of the present invention, a kit for updating or retrofitting a shock absorber having an adjustable height according to claim 8 of the claims is proposed.

[0023] According to one aspect of the present invention, a method of operating a shock absorber having an adjustable height according to claim 9 of the claims is proposed. The dependent claims of the claims refer to preferred and advantageous embodiments of the present invention.

Brief Description of the Drawings

[0024] Other aspects and advantages of the present invention will become more apparent from the following detailed description of some examples in embodiments illustrated merely as examples and not limited to the accompanying drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0025] In connection with a version of the present invention, FIG. 1 shows a shock absorber assembly having an adjustable height generally indicated by reference numeral 1, which shock absorber assembly can be installed on a two-wheeled vehicle (not shown), or a sidecar, i.e., a three- or four-wheeled lightweight vehicle of the type that tilts at corners.

[0026] The shock absorber assembly 1 with adjustable height in the version illustrated in FIG. 1 is a shock absorber 2 having at least one spring 3, for example a helical spring coaxial with the shock absorber 2, the spring 3 having a first end 4 and a second end 5, the shock absorber 2, and at least one hydraulic fluid type pusher 6 which is also coaxial with the shock absorber 2 and is installed in series with respect to the spring 3, the pusher 6 acting on one of the two ends 4, 5 of the spring 3, and a pressurized hydraulic fluid source 7 for operating the pusher 6, and basically comprises.

[0027] The shock absorber assembly with adjustable height according to the present invention can be applied to different types of suspensions, for example, telescopic forks for motorcycles. In this case, the pusher can be installed in series with respect to each spring in the fork slider, but it should be noted that it does not always need to be coaxial with the shock absorber, and it can also be configured as an actuator with a standard hydraulic cylinder, that is, a non-circular single-acting cylinder.

[0028] The shock absorber 2 has a nominal length L and includes at least two joints 8, 9 operably connected to the vehicle suspension.

[0029] The shock absorber 2 further has a first support base 10 positioned at a first support position P1 and a second support base 11 positioned at a second support position P2, and the spring 3 has a first end 4 resting at a first position P1 of the first support base 10 of the shock absorber 2 and a second end 5 resting at a second position P2 of the second support base 11 of the shock absorber 2.

[0030] The pusher 6 can change the support position P1 or P2 at one end 4 or 5 of the spring 3. In particular, in the version of FIG. 1, this pusher assembly 6 is positioned to act in contact with the first end 4 of the spring 3 and changes the first support position P1 of the first end 4 of the spring 3.

[0031] As an alternative, the pusher 6 can be positioned to contact and act on the second end portion 5 of the spring 3 by changing the second support position P2 of the second end portion 5 of the spring 3, and if possible, two pushers 6 can be provided to change both the support positions P1 and P2 of the spring 3. It should be noted that this is possible.

[0032] By changing the support position P1, or the support position P2, or both the support positions P1 and P2, the preload of the spring 3 can be changed. In this case, the initial preload can be increased, or the initial preload can be decreased or canceled.

[0033] As a result, the height of the shock absorber group 1, and more generally the height of the vehicle (vehicle height) equipped with the shock absorber group 1 can be changed. That is, by increasing the preload of the spring 3, the vehicle height actually increases, which means that the sag of the suspension under the load caused by the vehicle's own weight and the load applied to the vehicle decreases. Also, by decreasing (or canceling) the preload of the spring 3, the vehicle height actually decreases, which means that the sag of the suspension under the load increases.

[0034] The pusher 6 has a hydraulic actuator driven by a pressurized hydraulic fluid source 7. In FIGS. 1 and 2, the hydraulic actuator is configured as an annular cylinder 12 installed in series with the spring 3.

[0035] The assembly including the spring 3 and the cylinder 12 can be replaced with a simple spring of a non-adjustable shock absorber. Therefore, the shock absorber assembly 1 according to the present invention can be regarded as or sold as an upgrade or retrofit for an existing shock absorber without height adjustment.

[0036] Even in the case of a telescopic fork for a motorcycle, the spring and pusher assembly according to the present invention can be substituted for a simple spring provided on each slider of a pre-existing fork, and thus, the shock absorber assembly 1 according to the present invention can constitute an update or a retrofit of a pre-existing telescopic fork.

[0037] The shock absorber assembly having an adjustable height according to the present invention can also be used as original equipment in newly produced vehicles.

[0038] Figure 2 shows the cylinder 12 in cross-section, which cylinder 12 has a sleeve 13, a hollow portion 14 fixed to the sleeve 13, and a piston 15 sliding in a sealed state within the hollow portion 14. Thus, the cylinder 12 can be inserted onto a pre-existing shock absorber by substituting it for a portion of the preceding spring, and the sleeve 13 must have an inner diameter corresponding to the outer diameter of the pre-existing shock absorber.

[0039] The pressurized hydraulic fluid source 7 is directly connected to the pusher 6 by a pipe 16 without an intermediate valve.

[0040] This pipe 16 is in fluid communication with the cylinder 12 of the pusher 6, and for this purpose, the pipe 16 is fixed to a hydraulic connection 18 that communicates with the internal chamber of the cylinder 12.

[0041] It should be noted that due to the direct connection between the pressurized hydraulic fluid source 7 and the pusher 6, the shock absorber assembly 1 according to the present invention is simpler, less expensive, and more reliable than known solutions having one or more solenoid valves.

[0042] As described above, the cylinder 12 is a single-acting cylinder that is actively actuated by a hydraulic fluid only to increase the preload of the spring 3. When the preload of the spring 3 must be decreased or canceled when lowering the vehicle, it is the same spring 3 that empties the hydraulic fluid from the internal chamber of the cylinder 12 by pushing the piston 15 of the cylinder itself.

[0043] Since the cylinder 12 is of the single-acting type, the structural form of the cylinder 12 is particularly simple, lightweight, highly reliable, and has a low manufacturing cost.

[0044] The pressurized hydraulic fluid source 7 has a hydraulic pump 19 that is powered by an electric motor unit 20.

[0045] The hydraulic pump 19 includes a piston 21 that slides within the hydraulic cylinder in a sealed state and that also linearly operates bidirectionally by an electric motor assembly 20 within the stroke limit of the same piston 21 (see Figure 2), a single-acting hydraulic cylinder having the piston 21.

[0046] Therefore, the implemented hydraulic pump 19 is simple, lightweight, highly reliable, and inexpensive to construct.

[0047] According to what is shown in Figure 2, the above-described motor assembly 20 includes a rotary type electric motor 22, a possible reduction unit 23, such as a planetary gear reduction unit, and a mechanism 24 that converts the rotary motion into a linear motion that moves the piston 21, and also provides an electrical connection portion 25 for the electric motor 22.

[0048] According to the above-described structural form having the rotary type electric motor 22, a possible reduction unit 23, such as a planetary gear reduction unit, and a mechanism 24 that converts the rotary motion of the electric motor 22 into a linear motion, it is possible to equalize the power, use a small and lightweight electric motor, and obtain a limited installation area.

[0049] The mechanism 24 for converting rotational motion into linear motion can be realized in different ways, for example, by a toothed wheel engaging with a rack, a thrust crank mechanism, a cam and a follower, and in particular, by a screw 25 and a nut screw 26 that are operably connected to each other.

[0050] As shown in FIG. 2, the screw 15 is connected to the electric motor 22, and the nut screw 26 is connected to the piston 21. Of course, these elements 25 and 26 can be exchanged with each other.

[0051] Therefore, similar to the hydraulic actuating device of a brake or a clutch in a power vehicle, a direct connection is realized between the hydraulic type pump 19 and the cylinder 12.

[0052] In this way, by controlling the rotation of the screw 25 in the motor assembly 20, the output of the piston 21 of the cylinder 12 can be positioned in millimeters. As described above, the operation occurs in both the one-way and the other-way bidirectionally within the limit set by the stroke of the piston 21.

[0053] An important feature of the present invention is that the shock absorber assembly 1 having an adjustable height has an accumulator tank assembly 27 that is fluid-connected to the cylinder 12 of the pusher 6 by a second pipe 17 fixed to the hydraulic connection portion 18 of the cylinder 12.

[0054] This accumulator tank assembly 27 includes at least one tank 28, at least one low-pressure accumulation chamber 29, a device having a thin film 30 filled with gas or a device including an assembly having a hydraulic fluid separator, and a mechanical spring (not shown). The at least one low-pressure accumulation chamber 29 and at least one solenoid valve 31 having two positions for controlling the opening and closing of the hydraulic fluid inlet / outlet port.

[0055] By opening the solenoid valve 31, the accumulator tank assembly 27 rapidly discharges any pressure present within the pusher 6, enabling the immediate release of the spring preload of the shock absorber and, as a result, causing the vehicle to lower.

[0056] The solenoid valve 31 is configured to have a large cross-sectional port where the pressure drop of the hydraulic fluid decreases, providing low resistance to the discharge of the hydraulic fluid within the cylinder 12 of the pusher 6 and enabling the rapid lowering of the vehicle.

[0057] When the solenoid valve 31 is closed, the shock absorber assembly 1 operates in the conventional manner, which is because the hydraulic fluid present within the circuit is, as a whole, housed within the hydraulic line including the hydraulic pump 19, the pipe 16, and the cylinder 12 of the pusher 6.

[0058] In this way, the preload of the spring 3, and thus the vehicle height under load, can be adjusted with extremely precise positioning control.

[0059] When a rapid descent of the vehicle is required starting from an arbitrary height position of the vehicle, for example, from an arbitrary preload position of the spring 3 greater than the minimum preload condition of the spring 3, the solenoid valve 31 opens and rapidly discharges the hydraulic fluid from the cylinder 12 of the pusher assembly 6 towards the accumulator tank assembly 27, and the support position P1 or P2 of the spring 3 can be moved, thereby shortening the length under load of the shock absorber 2.

[0060] At this point, that is, while performing the above-described rapid discharge of the hydraulic fluid and still maintaining the opening of the solenoid valve 31, the hydraulic pump 19 draws in the hydraulic fluid from the tank assembly 27 where the piston 21 returns to the position determining the minimum preload. That is, the piston 21 is pulled back and draws in the hydraulic fluid from the tank assembly 27 towards the main circuit consisting of the same hydraulic pump 19, the pipe 16, and the cylinder 12 of the pusher 6.

[0061] Emptying the accumulator tank 28 is assisted by the pressure in the accumulation chamber 29, which must have a value that is not too high, i.e., it must allow for the complete discharge of the cylinder 12 of the pusher 6. Usually, the pressure in the accumulation chamber 29 is between 2 and 4 bar, i.e., between 0.2 and 0.4 MPa.

[0062] When the hydraulic pump 19 returns to the minimum preload position, the solenoid valve 31 closes and the shock absorber assembly 1 is ready for another operating cycle.

[0063] According to the second version of the invention shown in FIG. 4, the shock absorber 102 is equipped with a pusher 6 having a hydraulic cylinder 12 with a displacement stroke C, and this pusher 6 is positioned at either end of the shock absorber 102 where the joints 8, 9 of the shock absorber 102 to the vehicle suspension are located.

[0064] The other components of the shock absorber assembly 1 with adjustable height according to this version are the same as those of the version described above and will not be described further.

[0065] The effect of introducing or emptying hydraulic fluid into the hydraulic cylinder 12 is to directly adjust the stroke C of the cylinder 12 and, as a result, the loading length of the shock absorber 102, rather than adjusting the preload of the spring 3 as in the version described above.

[0066] The effect and operation of the shock absorber assembly 1 with adjustable height according to this version are exactly similar to those of the version described above. By operating the pusher 6, even when the shock absorber 102 is in a normal load state and the shock absorber 102 has a length shorter than the normal length L, the length of the shock absorber 102 increases due to the available stroke C from the hydraulic cylinder 12, and as a result, the vehicle height increases.

[0067] Of course, by reducing (or setting to zero) the available stroke C from the hydraulic cylinder 12, the length under the load of the shock absorber 102 is reduced, so the vehicle height is reduced.

[0068] According to the third version of the present invention shown in FIG. 5, the accumulator tank assembly 27 is integrated with the pressurized hydraulic fluid source 7, that is, the accumulator tank assembly 27, the hydraulic pump 19 and the motor assembly 20 constitute a single unit, and the second pipe 17 can be even shorter in length and can even be eliminated, which is because the accumulator tank assembly 27 is positioned extremely close to or can be integrated with the outlet of the hydraulic pump 19.

[0069] In this third version of the present invention, the integration of the components 7 and 27 enables some weight reduction and faster installation of these components on the vehicle. In the first version of the present invention, the separation of the components 7 and 27 can help find available space in the vehicle when these components can be arranged at different positions.

[0070] Furthermore, regarding this third version, other components, especially the shock absorber 2, remains the same as that of the first version of the present invention. As an alternative, the shock absorber 102 of the second version described above can be used.

[0071] In this way, it has been found how the present invention achieves the intended purpose.

[0072] Various changes and modifications can be made in the present invention without departing from the scope of the present invention and can also be conceived.

[0073] Furthermore, all elements can be replaced by other technically equivalent elements. In fact, the materials used as well as the accompanying shapes and dimensions can vary widely as necessary without departing from the scope of protection of the claims of the patent claims.

Claims

Claim 1 A shock absorber assembly (1) having an adjustable height for a two-wheeled powered vehicle or a sidecar, i.e., a three-wheeled or four-wheeled lightweight vehicle of the type that tilts at corners, the shock absorber assembly (1) comprising a shock absorber (2, 102) having a coaxial helical spring (3) with at least one shock absorber (2, 102), having a nominal length (L), and having at least two joints (8, 9) operatively connected to the suspension of the vehicle, the spring (3) having a first end (4) and a second end (5), the shock absorber (2, 102); at least one hydraulic fluid pusher (6) installed in series with respect to the spring (3), the pusher (6) acting on either end (4, 5) of the spring (3) or on either joint (8, 9); a pressurized hydraulic fluid source (7) fluidly connected to the pusher (6) to operate the pusher (6); and an accumulator tank assembly (27) fluidly connected to the pusher (6), the accumulator tank assembly (27) having at least one tank (28) and at least one solenoid valve (31) for controlling the opening and closing of the inlet / outlet opening of the hydraulic fluid in the tank (28), the solenoid valve (31) sliding on the circumferential surface of the port having the inlet / outlet opening between a closed position where the solenoid valve (31) crosses the inlet / outlet opening to the side of the tank and an open position located on the side farther from the tank than the closed position to open and close the inlet / outlet opening, in the shock absorber assembly (1), the pressurized hydraulic fluid source (7) is directly connected to the pusher (6) via a pipe (16) fixed to a hydraulic connection portion (18) communicating with an internal chamber of a cylinder (12) of the pusher (6) without passing through an intermediate valve, and the accumulator tank assembly (27) is connected to the pusher (6) via a second pipe (17) fixed to the hydraulic connection portion (18). A shock absorber assembly characterized by this. Claim 2 In the shock absorber assembly according to claim 1, the accumulator tank assembly (27) has a device having a gas-filled thin film (30), or a device including a set of a hydraulic fluid separator and a mechanical spring, the shock absorber assembly.

3. In the shock absorber assembly according to claim 1 or 2, the solenoid valve (31) has a port for the hydraulic fluid having a relatively large cross section so as to provide a low resistance to the discharge of the hydraulic fluid located in the pusher (6), the shock absorber assembly.

4. In the shock absorber assembly according to any one of claims 1 to 3, the pressurized hydraulic fluid source (7) has a single-acting hydraulic pump (19) driven by a motor via an electric type motor assembly (20), the shock absorber assembly.

5. In the shock absorber assembly according to claim 4, the single-acting hydraulic pump (19) has a single-acting hydraulic cylinder, and the single-acting hydraulic cylinder has a piston (21) that slides in a sealed state within the hydraulic cylinder, and the piston (21) is linearly operated bidirectionally by the motor assembly (20) within the stroke limit of the piston (21) itself, the shock absorber assembly having the piston (21).

6. In the shock absorber assembly according to claim 4 or 5, the motor assembly (20) has a rotary electric motor (22), a speed reducer (23) with a planetary gear, and a mechanism (24) that converts the rotational motion of the electric motor (22) into a linear motion, the shock absorber assembly.

7. In the shock absorber assembly according to claim 6, the mechanism (24) that converts the rotational motion into a linear motion has a mechanism formed by a screw (25) and a nut screw (26) that are operably connected to each other, the shock absorber assembly.

8. In the shock absorber assembly according to any one of claims 1 to 7, the shock absorber assembly is an upgrade or a retrofit.

9. A driving method for a shock absorber assembly having an adjustable height, Preparing a shock absorber assembly (1) according to any one of claims 1 to 7, having an adjustable height for a two-wheeled powered vehicle or a sidecar, i.e., a three-wheeled or four-wheeled lightweight vehicle of the type that tilts at corners. Adjusting the preload of the spring (3) or the length of the shock absorber (102), and thus adjusting the loaded vehicle height by precise positioning control. In a driving method, comprising: When starting from an arbitrary height of the vehicle and when the vehicle needs to descend, opening the solenoid valve (31) that enables the discharge of the hydraulic fluid from the cylinder (12) in the pusher (6) towards the accumulator tank assembly (27). Maintaining the opening of the solenoid valve (31), and Recovering the hydraulic fluid from the accumulator tank assembly (27) towards the pressurized hydraulic fluid source (7) and the pusher (6), and returning the pressurized hydraulic fluid source (7) to the minimum preload position of the spring (3) or the minimum length of the shock absorber (102). A driving method, characterized by comprising the above steps.

10. In the driving method of a shock absorber assembly having an adjustable height according to claim 9, the steps are performed in the order described in claim 9, and further comprising closing the solenoid valve (31) to prepare the shock absorber assembly having an adjustable height for a new operating cycle.

11. In the driving method of a shock absorber assembly having an adjustable height according to claim 9 or 10, the pressurized hydraulic fluid source (7) has a single-acting hydraulic cylinder, and the single-acting hydraulic cylinder has a piston (21) that slides under a sealed state in the hydraulic cylinder, and the piston (21) linearly operates bidirectionally by an electric motor assembly (20) within the stroke limit of the piston (21) itself.

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