A shock absorber with multiple damping control laws

Abstract

The present invention relates to a shock absorber with multiple damping control laws, comprising a regulating body (12) having a primary valve (14) and a secondary valve (15) and a drive shaft (21) having multiple flow passages (16, 17), the drive shaft (21) being accommodated in an axial orifice (36) of a piston pin (30) having multiple orifices (31, 32, 33) intended to be aligned with the flow passages (16, 17) by the rotation of the drive shaft (21) and to determine the damping control law, and the second orifice (32) is in direct communication with the regulating body (12), the regulating body (12) comprising a floating piston (13) having an annular configuration and made of elastic material, which gradually transmits a force to the primary valve (14) depending on the pressure it receives.

Description

Technical Field

[0001] The present invention relates to a shock absorber capable of generating a plurality of damping control rules in order to adapt the damping of a device, which is usually a vehicle but can be of any type of mechanism, to the requirements related to its operating conditions. For each instant, the most appropriate damping control rule is selected, so that the shock absorber can be manually changed by the driver or operator himself, or automatically changed by a computer, so that the shock absorber can adapt to the requirements related to the operating conditions of the device.

[0002] The shock absorber is particularly applicable in the field of hydraulic devices, especially in the field of shock absorbers for vehicles.

Background Art

[0003] A shock absorber is a device aimed at damping the vibration of a suspension by dissipating kinetic energy until the suspension returns to its equilibrium position. A very common development case focuses on applications to vehicles.

[0004] Focusing on the automotive field, shock absorbers have a decisive influence on both stability and comfort. In fact, the adjustment of the hydraulic load generated by the shock absorber represents a compromise between both factors. -Regarding stability, the dynamic control of the vehicle is carried out with a low suspension expansion and contraction speed and a low vibration frequency corresponding to the natural frequency of the sprung mass (cab), typically within the range of 1 - 2 Hz for a passenger car. In this operating condition, a high level of damping, that is, a high hydraulic load is required; -Regarding comfort, the control is mainly related to medium and high suspension expansion and contraction speeds occurring at medium or high vibration frequencies. The reference frequency is the natural frequency of the unsprung mass (wheel / suspension), typically within the range of 8 - 15 Hz for a passenger car. Comfort can be enhanced by reducing the damping level and decoupling the movement of the wheels from the vibration of the chassis.

[0005] Therefore, there is a need for a damper that can adjust its load level to match the characteristics of the vibration to be damped.

[0006] Conventional shock absorbers provide variable damping characteristics based on speed, but these are predetermined and cannot be adapted by the user or computer. This is the fundamental reason why a compromise must be struck between comfort and stability when tuning the desired damping control law for a particular vehicle's suspension. This is an optimization process to find the best compromise for the characteristics that should be given to the vehicle.

[0007] On the other hand, when a vehicle prioritizes comfort, the suspension damping level is selected to isolate the movement of the wheels from the vehicle body as much as possible. In this way, the transmission of road irregularities to the passenger compartment is minimized.

[0008] On the other hand, when a vehicle prioritizes stability, the suspension is configured with a high damping level to minimize body movement.

[0009] Improvements to conventional shock absorbers consist of being able to adapt to the load level according to the desired purpose at any given time, and being able to select from a variety of damping control laws depending on whether it is desirable to change between higher stability and higher comfort.

[0010] At the current level of technology, there are different systems that allow a single shock absorber to produce multiple damping control laws. These systems are typically based on solenoid valves that can be controlled by linear actuators (solenoids) or rotary actuators (motors).

[0011] In particular, in low-cost systems, a common technical solution at the current level of technology is to incorporate a second piston to control the flow of oil through a passage connecting the two chambers separated by the first piston, thereby generating two damping control laws, one hard and one soft.

[0012] In the hard control law, the flow of oil through the passage is closed, while in the soft control law, the flow of oil through the passage is open, which is controlled by the configuration of the secondary piston. With this operating principle, it is possible to generate three or four damping control laws simply by adjusting the cross-sectional area of ​​the passage opened by the solenoid valve in stages.

[0013] However, incorporating a secondary piston comes with a series of drawbacks.

[0014] On the other hand, it is necessary to incorporate a series of passive elements into the secondary piston that can adjust / modify the fluid flow, which means an increase in the number of elements, leading to higher costs and the need for axial space.

[0015] On the other hand, the flow path constructed as an orifice at the rod pin must have a considerable flow path cross-section to achieve a low damping control law. This requires an increase in the diameter of the rod pin, resulting in an increase in the system's diameter and making implementation difficult. In addition, a larger pin diameter necessitates the use of certain larger pistons, valves, washers, and nuts, which also leads to further increases in product cost.

[0016] The written text of U.S. Patent No. 4,953,671A describes a shock absorber that can operate under different control laws by driving a control pin 31 attached to a shaft 30 rotatably inserted into a rod 7 of a piston 5. The shaft 30 has three longitudinal grooves 33, 34, 35 around it, and depending on the position of the shaft 30, different communications are formed between the upper chamber 3, the lower chamber 4 and the pressure chambers 15, 16, thereby the shock absorber behaves according to a soft damping control law when the communication between the lower chamber 4 and the upper chamber 3 is direct, or according to a hard damping control law when the communication is via the pressure chambers 15, 16.

[0017] The first groove 33 has a length such that at one end it communicates with the upper chamber 3 via a first orifice 36 in the rod 7 of the piston 5, and at the other end it communicates with a second orifice 37 in the rod 7 of the piston 5, which communicates with the pressure chamber 16 separated from the lower chamber 4 via a valve 12 having an orifice 14.

[0018] The second groove 34 is located radially opposite to the first groove 33 and has a length such that at one end it communicates with a third orifice 39 in the rod 7 of the piston 5, which communicates with a pressure chamber 15 separated from the upper chamber 3 via a valve 13, and at the other end it communicates directly with the lower chamber 4.

[0019] The third groove 35 connects the upper chamber 3 directly to the lower chamber 4 via the orifice 41 on the rod 7 of the piston 5.

[0020] In the above invention, the hard control law is achieved by transmitting pressure from the upper chamber 3 to the chamber 16 in order to increase damping during extension, and by transmitting pressure from the lower chamber 4 to the chamber 15 during compression. The shaft 30, by rotating within the opening of the rod 7, plays a role in enabling the transmission under the hard control law and in nullifying it under the soft control law. However, a gap is required between the shaft 30 and the opening of the rod 7 for the rotation to occur, and therefore, if an additional sealing system is not provided, a certain amount of pressure transmission will be permitted even under the soft control law. Since the pressure transmitted to chambers 15 and 16 acts directly on valves 12 and 13, a certain increase in force will occur even under the soft control law.

[0021] Another limitation of this invention is that it can only generate two damping control laws: a soft one and a hard one. In addition, as explained in the previous paragraph, the difference in force between the two may not be very large, and it may exhibit large variability depending on the gap between the shaft 30 and the opening of the rod 7.

[0022] Similarly, under the hard control law, the pressure transmitted from chambers 3 and 4 to valves 12 and 13 acts directly, resulting in a nearly instantaneous increase in damping force. This direct response lacks gradual force application, leading to a greater presence of acceleration peaks in the chassis and increased noise. Both of these effects limit the ability to maintain an appropriate level of comfort under the hard control law. [Overview of the project] [Means for solving the problem]

[0023] As described above, the present invention relates to a shock absorber capable of generating multiple damping control laws in order to adapt the damping of the device to the requirements related to its operating conditions.

[0024] Thus, the present invention describes a shock absorber having multiple damping control rules, comprising a regulating body having a primary valve and a secondary valve. The shock absorber also comprises a drive shaft housed in a piston pin and driven manually or automatically. The function of the drive shaft is to select a damping control rule, which is determined as described in this specification, automatically via an actuator or manually via a rod, depending on its position, which is positioned by rotation.

[0025] In the case of automatic drive, the actuator comprises a body housed within a rod, to which a drive shaft is attached. The drive shaft protrudes from the rod so as to be housed in an axial orifice formed in the piston pin, and is fixed to the rod as an extension, through which the piston passes via the axial orifice provided within it.

[0026] While it is common to understand that a shock absorber rod comprises the rod body and a piston pin, it should be noted that in this case, these two components are independent, and the rod and piston pin are considered separate entities, with the piston pin attached to the rod to house the actuator body.

[0027] The drive shaft has a plurality of flow paths, while the piston pin has a plurality of inlet and outlet orifices, whereby the two chambers of the shock absorber are connected. These orifices serve as the inlet or outlet of the fluid when the direction of the fluid flow changes, regardless of whether the shock absorber is undergoing an extension or compression operation. Alignment of the orifices with the flow paths enables circulation of the fluid in the shock absorber, which determines the damping control law that the shock absorber follows at that time.

[0028] The orifices in the piston pin include the following: - A first orifice that communicates the extension side chamber with the axial orifice of the piston pin, - A second orifice that communicates the axial orifice of the piston pin with the compression side chamber through an adjusting body, and - A leakage orifice that is located in the piston pin and rotated with respect to the first orifice, and communicates the extension side chamber with the axial orifice of the piston pin.

[0029] On the other hand, the flow paths of the drive shaft include the following: - A first flow path having a length that communicates the first orifice and the second orifice, - A second flow path having a length that communicates the first orifice and an opening at the end of the axial orifice of the piston pin.

[0030] The adjusting body forms a cavity having an annular configuration and having a floating piston made of an elastic material therein, whereby the floating piston achieves a progressive operation of the primary valve according to the pressure received, resulting in a progressive blockage of the piston flow through the said operation.

[0031] In this first embodiment where the shock absorber has a single adjusting body, the piston pin can be located as an extension of the leakage orifice and can be provided with a second leakage orifice having a larger flow path cross-section.

[0032] In a second embodiment, the buffer may also include an additional regulating body arranged in conjunction with the regulating body, the regulating body being connected to a second orifice, and the additional regulating body being located below the second orifice and similarly connected to an additional second orifice communicating the axial orifice of the piston pin with the compression chamber. In this case, the drive shaft also has a third flow path having a length such that the first orifice communicates with the additional second orifice, and the piston pin has a third leakage orifice arranged as an extension of the first orifice, preferably having a considerably smaller flow path cross-section with the intention of achieving a harder damping control law.

[0033] The fact that the additional regulator is positioned in conjunction with the regulator, that is, one is positioned following the other, means that the primary valve of the additional regulator is the secondary valve of the regulator, thereby enhancing the effect of the floating piston of the regulator by the effect of the additional floating piston of the additional regulator.

[0034] The shock absorber may also comprise two damping bodies, one on each side of the piston. In this way, the shock absorber can operate according to different damping control laws for both compression and extension.

[0035] The relationship between the flow path cross-sections of the piston pin orifices is preferably such that the flow path cross-section of the second leakage orifice is larger than that of the first orifice, the flow path cross-section of the first orifice is larger than that of the transverse orifice, and the flow path cross-section of the transverse orifice is then larger than that of the third leakage orifice. In any case, although this is an advantageous configuration, other relationships are possible, functional, and provide different damping control laws.

[0036] The buffer may also include a slide positioned between the flexible floating piston and the primary valve, which is slidable along the piston pin and transmits the force received from the floating piston to the primary valve over a configurable diameter, while also protecting the floating piston. The main purpose of introducing the slide as an intermediate element is to better protect the floating piston, thereby allowing it to operate at higher pressures.

[0037] On the other hand, the free end of the drive shaft may be provided with a longitudinal extension having a semicircular cross-section, while the axial orifice may be provided with an end orifice having an elongated cross-section that is eccentric with respect to the drive shaft. In this way, the movement of the drive shaft is limited to a quarter turn, preventing further rotation, as the wall of the end orifice acts as a mechanical stop together with the extension of the drive shaft.

[0038] In this situation, taking it a step further, the extension is a modified extension having a quarter-circular cross-section, and in addition, the shock absorber is fixed to the end of the piston pin and includes a disc with a semicircular orifice through which the modified extension passes, thereby limiting the free movement of the drive shaft to a quarter rotation, and allowing it to rotate another quarter rotation by dragging the disc.

[0039] In these cases, the aforementioned blocking systems may have other configurations with respect to the geometric shape of the cross-sections of the shaft and orifice in order to impose equivalent restrictions on their operation.

[0040] In summary, the main advantages offered by this solution can be considered as follows: - Simplicity: No secondary piston is required. A new piston valve design is provided, allowing for direct adjustment under load. This design is compatible with standard valve components. -Cost: The number of components has been significantly reduced by eliminating the secondary piston. - Energy Consumption: Rotary actuators (motors) consume less energy than linear actuators (solenoids) because energy is consumed only when changing from one position to another, and not when maintaining a position. -Compactness: The drive shaft is directly connected to the motor or actuator, can be installed inside the rod, and has very small dimensions, and like the drive shaft, the load on its rotation is minimized. At the current level of technology, the drive shaft is connected to the actuator via a control pin, and the shaft has a large diameter, and the friction of the shaft in the piston pin orifice is also large, and therefore the counter-torque due to the friction of the shaft in the piston pin orifice is also large. This large conflict requires a more powerful and larger actuator that cannot be accommodated inside the rod. - Standardization: The flow rate of fluid exchanged between the two chambers defined by the piston is small, as it is used only to modify permanent leakage (low speed) and supply it to the regulator (hard control law). This allows for the use of standard small-diameter piston pins, and similarly, standard pistons and valves, thus eliminating the need for oversized components. Conversely, in a double-piston system, most of the flow rate moved in the operation of the piston passes through the orifice of the piston pin, requiring a larger diameter.

[0041] Furthermore, as an alternative to using a rotary motor as an actuator, the drive shaft is used. Drive It can also be manually activated via a rod that is mounted on the shaft and extends outside the shock absorber's rod.

[0042] A series of drawings are included to complement the description of the present invention and to aid in making its features more easily understandable, according to preferred exemplary embodiments. These drawings are illustrative and not limiting. The following drawings are shown. [Brief explanation of the drawing]

[0043] [Figure 1] Figure 1(A) shows a longitudinal cross-sectional view of the shock absorber of the present invention that is automatically driven for extension. Figure 1(B) shows a longitudinal cross-sectional view of the shock absorber of the present invention that is manually driven from the outside for extension. [Figure 2] Figure 2(A) shows a longitudinal cross-sectional view of a shock absorber having an actuator for expansion and contraction in the first embodiment. Figure 2(B) shows a longitudinal cross-sectional view of a shock absorber having an actuator for expansion and contraction in the second embodiment. [Figure 3A] Figure 3A shows a detailed longitudinal cross-sectional view of the piston region of the buffer shown in Figure 1A in a stationary state in the first embodiment. [Figure 3B] Figure 3B shows a detailed longitudinal cross-sectional view of the piston region of the buffer shown in Figure 1A in a stationary state, according to the second embodiment. [Figure 4] Figure 4 shows the shock absorber from Figure 3A operating according to the hard damping control law, along with a magnified detail view of the regulating element. [Figure 4A] Figure 4A shows the details of the regulator. [Figure 5] Figure 5 shows the buffer of Figure 3A operating according to the intermediate damping control law. [Figure 6] Figure 6 shows the shock absorber of Figure 3A operating according to the soft damping control law. [Figure 7] Figure 7 shows the buffer of Figure 3A operating according to the ultra-soft damping control law. [Figure 8] Figure 8 shows a second embodiment relative to Figure 4, where the control law is hardened by changing the orifice in the piston pin, adding a flow path in the drive shaft, and using two adjusters. [Figure 9] Figure 9 shows a second embodiment relative to Figure 5, where the control law is hardened by changing the orifice in the piston pin, adding a flow path in the drive shaft, and using two adjusters. [Figure 10]Figure 10 shows a second embodiment relative to Figure 6, where the control law is hardened by changing the orifice in the piston pin, adding a flow path in the drive shaft, and using two adjusters. [Figure 11] Figure 11 shows a second embodiment relative to Figure 7, where the control law is hardened by changing the orifice in the piston pin, adding a flow path in the drive shaft, and using two adjusters. [Figure 12] Figure 12 shows a graph illustrating the change in damping force in relation to the shock absorber of the present invention shown in Figure 1, in accordance with the piston speed, during extension. [Figure 13] Figure 13 shows a graph illustrating the change in damping force in relation to the shock absorber of the present invention shown in Figure 2, in accordance with the piston speed, during expansion and contraction. [Figure 14A] Figure 14A shows the buffer of Figure 3A in an embodiment that has a mechanical locking system and focuses on only two control laws. [Figure 14B] Figure 14B shows an alternative embodiment of the locking system shown in Figure 14A, in which a separation bush and a rotation limiting plate are provided. [Figure 15] Figure 15 shows the buffer of Figure 3A, which has a mechanical locking system and focuses on three control laws. [Modes for carrying out the invention]

[0044] The present invention discloses a shock absorber capable of selecting up to four different damping control rules. This shock absorber can be driven externally, either automatically or manually. For this purpose, the shock absorber has a drive shaft (21). In the case of automatic selection, the drive shaft (21) is attached to an actuator (20) connected to a connector by a cable (22), and in the case of manual selection, it is attached directly to a mechanism (not shown). The damping control rules are selected simply by rotating the drive shaft (21) to the appropriate position and hydraulically connecting the appropriate orifices (31, 32, 32', 33, 34, 35, 36) to the appropriate flow paths (16, 17, 18), as described below.

[0045] Both the connector and the mechanism are known to the art and are mounted on the corresponding device so that an appropriate damping control law can be selected.

[0046] On the other hand, a two-tube shock absorber having an outer case (1) and an inner tube (2) in which a piston (4) is located has been considered, but this can be extended to other types of shock absorbers such as single-tube or three-tube shock absorbers.

[0047] Figures 1(A) and 1(B) show longitudinal cross-sectional views of the shock absorber of the present invention, which includes an adjustment body (12) in the compression chamber (6) of the shock absorber, thereby enabling automatic and manual selection of the damping control law for extension operation, respectively.

[0048] Next, Figure 2(A) shows the shock absorber of Figure 1(A) configured to provide multiple damping control laws for both extension and retraction movements by comprising a second adjuster (12) located in the extension chamber (5).

[0049] Figure 2(B) shows a second embodiment of the buffer shown in Figure 2(A), in which the communication between the adjusting body (12) and the extension chamber (5) and compression chamber (6) is modified.

[0050] There is no functional difference between these two embodiments. The embodiment in Figure 2(A) is adapted to a standard double-acting (DA) piston, and the embodiment in Figure 2(B) is adapted to a double-acting (DAC) piston with radial orifices. The difference between these two embodiments lies in the radial orifice in the piston pin (30). In the second embodiment, the orifice for drawing oil into the regulator during the compression phase requires more holes than in the first embodiment because it draws oil from "below" the corresponding primary valve (14) rather than directly from the extension chamber (5) or compression chamber (6).

[0051] Figure 3A shows in more detail the components of the present invention, namely the actuator (20) and piston (4). As can be seen from the figure, the piston pin (30) has a first seal (26) with the drive shaft (21) and a second seal (27) with the rod (3). These two seals (26, 27) form an oil-protected, leak-free space for housing the actuator body (23), which is an electrical component. In the manually started system shown in Figure 1(B), the seals (26, 27) prevent oil leakage from the buffer through the axial opening of the rod (3).

[0052] In addition, the piston pin (30) also includes a first orifice (31) communicating with the extension chamber (5), a second orifice (32) communicating with the regulating body (12), a leakage orifice (33) rotating relative to the first orifice (31), a second leakage orifice (34) having a larger cross-section than the leakage orifice (33) for the piston pin (30) to pass through, and an axial orifice (36) for housing a drive shaft (21) through which all of the above orifices (31, 32, 33, 34) communicate. The figure also shows the configuration of a drive shaft (21) having a circular cross-section. The drive shaft (21) includes a first recess defining a first flow path (16) and, although not required, a second recess located radially opposite and defining a second flow path (17). The recess of the second flow path (17) is preferably larger than that of the first flow path (16) in order to reduce the pressure drop during fluid flow.

[0053] The first flow path (16) is positioned and has a length such that it completely connects the inlet orifice (31) and the outlet second orifice (32) without reaching the free end of the drive shaft (21).

[0054] Next, the second flow path (17) is preferably located radially opposite the first flow path (16), and, like the first flow path (16), completely connects the first orifice (31) and the second orifice (32), but differs in that the length of this second flow path (17) reaches the free end of the drive shaft (21).

[0055] On the other hand, with respect to the regulator (12), it should be noted that when the buffer is in the stationary position, the floating piston (13) is not in contact with the primary valve (14).

[0056] The operation of the buffer of the present invention during extension is described below in cases where it operates according to different control laws. In this situation, the fluid branches, with a portion flowing through the through conduit (28) and main fixed flow passage (42) that penetrate the piston (4), or along the transverse passage through the primary valve (14) when opened after a certain fluid velocity, from the extension chamber (5) to the compression chamber (6), while the remainder of the fluid passes through the central passage through the piston pin (30). The transverse passage that penetrates the piston (4) is formed in all damping control laws and is a normal passage in conventional buffers, which may be affected by the flow rate when the flow passage is partially closed, while the central passage through the piston pin (30) is described in detail below in different damping control laws.

[0057] Figure 3B shows an alternative embodiment to that shown in Figure 3A. In Figure 3B, the slide (47) is inserted between the flexible floating piston (13) and the primary valve (14). The slide (47) is movable along the same axis as the flexible floating piston (13) and is pushed by the flexible floating piston (13) to transmit force to the primary valve (14) in a diameter defined by the step that forms the outermost region. The basic operation of the system is the same, and the slide (47) provides two advantages.

[0058] The first advantage is that the flexible floating piston (13) is well protected during operation because it is completely enclosed in all directions by rigid walls. Therefore, it can operate at higher pressures / forces without the risk of failure due to lack of durability or deterioration over time caused by continuous operating cycles.

[0059] A second advantage is that the diameter of the primary valve (14) to which the force generated in the flexible floating piston (13) is transmitted becomes selectable. This provides a degree of freedom in establishing the level of connection between the regulator (12) and the primary valve (14). Consequently, the gradual (roundness) level of the damping force when the primary valve (14) is open can be changed in the hard control law, which is achieved by making the floating piston (13) flexible.

[0060] Figure 4 shows a shock absorber operating according to a hard damping control law, where the intention is to hinder fluid flow between the extension chamber (5) and the compression chamber (6) in order to increase the load. In this case, the fluid circulates from the extension chamber (5) to the compression chamber (6) through the conduit (28), the main fixed flow passage (42), and the first flow path (16). The drive shaft (21) is rotated to a position such that the first flow path (16) communicates with the first orifice (31), the second orifice (32) communicates with the second flow path (17), and the leakage orifice (33) and the second leakage orifice (34) are blocked, as shown in sections EE and SS. On the one hand, by closing the leakage orifice (33) and the second leakage orifice (34), the leakage cross-section is minimized and confined to the fixed flow passages (42, 43) of the primary valve (14) and secondary valve (15), respectively, generating the maximum level of damping for the low-speed operation of the piston (4). In this way, the fluid enters through the first orifice (31), passes through the first flow path (16), exits through the second orifice (32), and circulates through the secondary fixed flow passage (43) located between the regulator (12) and the secondary valve (15).

[0061] Figure 4A shows an enlarged detail view of the regulator (12) having a floating piston (13) together with the primary valve (14) and secondary valve (15).

[0062] On the other hand, the conduit (28) is in communication with the pressure side chamber (6) via a primary valve (14) having a main fixed flow passage (42).

[0063] On the other hand, the first flow path (16) is connected to the access flow path (40) via the second orifice (32), thereby allowing the fluid to enter the regulating chamber (41). The fluid can also exit the regulating chamber (41) toward the pressure side chamber (6) via the secondary valve (15) which has a secondary fixed flow passage (43).

[0064] The fixed flow passages (42,43) are always open, but whether the primary valve (14) or secondary valve (15) is closed or not, these are actually optional and may not be present. In either case, as the fluid pressure increases, the corresponding valves (14,15) open, expanding the flow path cross-section for fluid circulation.

[0065] Therefore, if a secondary fixed flow passage (43) is provided, or if the pressure is sufficient to open the secondary valve (15), some of the fluid flows directly into the pressure chamber (6), but some of this fluid enters the regulating chamber (41) and acts on the floating piston (13) to pressurize the primary valve (14) and attempt to close it. As a result, the conduit (28) is closed in proportion to the force generated by this pressure, making it difficult for the fluid to pass through the conduit (28) of the piston (4). Figure 4 reflects the movement of the floating piston (13) that moves the primary valve (14), which occurs only in the case of the hard control law, as described below.

[0066] In a preferred embodiment, the floating piston (13) is a deformable elastic element, for example, made of rubber, and has an annular configuration. Thus, at the moment the floating piston (13) contacts the primary valve (14), force is transmitted in the contact area, which is usually the central region of the valve (14). However, as the pressure increases, the floating piston (13) deforms and tends to move toward the outer diameter of the valve (14) while transmitting force over a larger surface area. This is because oil can freely escape between the secondary valve (15) and the regulator case (44) of the regulator (12), but not in the other space in contact with the floating piston (13) where the oil, which is essentially incompressible, is confined. This deformation can be seen in detail in Figure 4 and results in a smooth and gradual transition between low-speed and medium-speed damping, as shown in the hard control law in Figure 12.

[0067] Figure 5 shows a shock absorber operating according to the most commonly used mean damping control law. In this case, as shown in sections EE and SS, the fluid circulates from the extension chamber (5) through the conduit (28) and the leakage orifice (33) connected to the second passage (17) of the drive shaft (21) to reach the pressure chamber (6) directly. In this way, the leakage cross-section of the hard control law is increased, and the damping related to the low-speed operation of the piston (4) is reduced. The drive shaft (21) is rotated to a position where the fluid can pass through the second leakage orifice (34) connected to the first passage (16), which is not connected to the pressure chamber (6) because the length of the first passage (16) does not reach the free end of the drive shaft (21), although fluid access to the first orifice (31) is blocked. In this case, since the floating piston (13) does not move, the fluid circulates through the conduit (28) without any additional restrictions, reducing the damping of the hard control law related to the medium and high-speed operation of the piston (4).

[0068] Figure 6 shows a shock absorber operating according to a soft damping control law, where the intention is to facilitate fluid flow between the extension chamber (5) and the compression chamber (6) to reduce the load. In this case, the fluid circulates from the extension chamber (5) to the compression chamber (6) through the conduit (28) and the second flow path (17). The drive shaft (21) is rotated to a position where the second flow path (17) is connected to the first orifice (31) and the leakage orifice (33) and the second leakage orifice (34) are blocked, as shown in section EE. Since the first orifice (31) has a larger flow path cross-section than the leakage orifice (33), it is larger than the leakage cross-section in the intermediate control law, and as a result the damping force is reduced. In addition, the fluid continues to circulate through the conduit (28) without any further restrictions.

[0069] Thus, the fluid enters the first orifice (31), circulates through the second passage (17), and exits mainly through the opening at the end of the axial orifice (36) of the piston pin (30) until it reaches the pressure chamber (6). A minimal amount of oil flow bypasses through the second orifice (32) toward the regulator chamber (41). However, due to the very large resistance to fluid flow by the second orifice (32), particularly due to the access passage (40), this flow becomes negligible compared to the opening at the end of the axial orifice (36) and has no force to move the floating piston (13). This lack of effect is facilitated by the presence of the floating piston (13) as an element that transmits the pressure of the regulator (12) to the primary valve (14). If the floating piston (13) is not provided, the pressure would be transmitted directly in the regulator (12), and even a minimal amount of oil flow would be able to apply a constant closing pressure to the primary valve (14). In such cases, the soft control law generates a greater damping force from a constant piston (4) speed than the intermediate control law.

[0070] Figure 7 shows a shock absorber operating according to an ultra-soft damping control law. In this case, the drive shaft (21) is rotated to a position where the fluid circulates from the extension chamber (5), through the conduit (28), through the second flow path (17), and through the second leakage orifice (34) to reach the pressure chamber (6) directly, as shown in sections EE and SS. In this situation, the fluid circulates through an orifice with a larger cross-section than any of the previously described cases, because the second leakage orifice (34) has the largest flow path cross-section among all the orifices (31, 33, 34) communicating with the extension chamber (5). Therefore, the resistance to fluid flow in this embodiment is lower than in the previously described embodiments, resulting in an ultra-soft damping control law.

[0071] As shown in Figure 5, in this case the leakage orifice (33) is connected to the first flow path (16) which has a closed end, and therefore the fluid does not circulate in this manner.

[0072] Figures 8-11 show second embodiments relating to Figures 4-7, respectively, in which the buffer includes four modifications for hardening the control law.

[0073] The first modification involves the addition of an additional regulator (12') having a corresponding additional floating piston (13'), an additional secondary valve (15'), and an additional second orifice (32'), so that the compression chamber (6) has two regulators (12, 12') instead of one.

[0074] The second modification consists of omitting the second leakage orifice (34).

[0075] The third modification relates to the first orifice (31) and the second orifice (32) of the piston pin (30). Thus, a third leakage orifice (35) is provided, which is located as an extension of the existing first orifice (31) but has a substantially smaller flow channel cross-section, and an additional second orifice (32') is provided, which is located in correspondence with an additional regulator (12').

[0076] The first flow path (16) and the second flow path (17) are both maintained in length; that is, the first flow path (16) has a length that connects the first orifice (31) and the second orifice (32), while the second flow path (17) has a length that connects the first orifice (31) and the free end of the drive shaft (21). In addition, the drive shaft (21) is provided with a third flow path (18) that connects the first orifice (31) and two second orifices (32, 32'), but does not reach the free end of the drive shaft (21). Furthermore, this is preferably symmetrically positioned between the first flow path (16) and the second flow path (17) in a counterclockwise direction when viewed from the free end of the drive shaft (21).

[0077] Therefore, Figure 8 shows a buffer operating according to the ultra-hard control law. The fluid enters through the first orifice (31), circulates through the third passage (18), and exits through two second orifices (32, 32'), in addition to passing through the primary valve (14) to the pressure chamber (6) via the conduit (28). Here, the third leakage orifice (35) and the second passage (17) are blocked. The leakage orifice (33) communicates with the first passage (16), which is similarly blocked as it does not communicate with the opening at the end of the second orifice (32) or the axial orifice (36). This situation is shown in sections EE, S1-S1 and S2-S2. In this situation, a portion of the fluid enters the two regulators (12, 12') and acts on the corresponding floating pistons (13, 13'). The difference in this case is that the fluid exiting the additional second orifice (32'), located further away, not only goes directly to the pressure chamber (6) via the additional secondary valve (15'), but also enters the chamber of the additional regulator (12'), pressing the additional floating piston (13') and pressurizing the secondary valve (15) of the regulator (12). This tends to block the flow of fluid from the upper second orifice (32) to the pressure chamber (6), forcing the fluid towards the regulator (12), pushing the floating piston (13) of the regulator (12) to move the primary valve (14), thereby attempting to close the valve to block the flow of fluid through the conduit (28) of the piston (4). This closing is proportional to the force generated by this pressure. However, the secondary valve (15) and the primary valve (14) are pushed by the floating pistons (13') and (13), respectively. This increases the resistance to the flow of oil through the secondary valve (15) compared to the previously described design. This increased resistance creates greater pressure in the regulating chamber (41), which ultimately causes the floating piston (13) to exert an even greater force on the primary valve (14).

[0078] Figure 9 shows a shock absorber operating according to a hard damping control law. In this case, the drive shaft (21) is rotated to a position where the fluid reaches the compression chamber (6) from the extension chamber (5) via the conduit (28) and two other paths. On the one hand, the fluid reaches through the third leakage orifice (35) and circulates through the second flow path (17), which connects directly to the compression chamber (6) via an opening at the end of the axial orifice (36). On the other hand, the fluid also reaches through the first orifice (31) and circulates through the first flow path (16), which connects to the second orifice (32), and through the access flow path (40) and the secondary valve (15) of the regulator (12), via the secondary fixed flow path (43) if present, or via the opening of the secondary valve (15) itself if a sufficient pressure level has been reached. In this situation, some of the fluid flows directly to the pressure chamber (6) via the secondary valve (15), while the rest of the fluid enters the regulating chamber (41), acting on the floating piston (13) to pressurize the primary valve (14) and attempt to close it, thereby making it difficult for the fluid to pass through the piston (4) conduit (28), where the conduit (28) is closed in proportion to the force generated by this pressure. If there is no secondary fixed flow passage (43), or if the pressure is not high enough to open the secondary valve (15), all the fluid flows into the regulating chamber (41), acting on the floating piston (13) to close the primary valve (14) with additional pressure.

[0079] Figure 10 shows a buffer operating according to the intermediate damping control law. In this case, the fluid travels through the conduit (28) and through the leakage orifice (33) connected to the second passage (17) of the drive shaft (21), as shown in sections EE, S1-S1 and S2-S2, from the extension chamber (5) to the compression chamber (6) and directly to the compression chamber (6). The drive shaft (21) blocks fluid access to the first orifice (31), but the fluid is rotated to a position where it can pass through the third leakage orifice (35) connected to the first passage (16), which is not connected to the compression chamber (6) because the length of the first passage (16) does not reach the free end of the drive shaft (21). In this case, the floating piston (13) does not move, so the fluid circulates through the conduit (28) without any additional restrictions.

[0080] Figure 11 shows a shock absorber operating according to a soft damping control law. In this case, the fluid circulates through the conduit (28) and the second flow path (17) from the extension chamber (5) to the compression chamber (6). The drive shaft (21) is rotated to a position such that the second flow path (17) is connected to the first orifice (31), as shown in sections EE, S1-S1 and S2-S2, and the leakage orifice (33) and the third leakage orifice (35) remain blocked because these orifices are connected to the first flow path (16) and the third flow path (18), respectively, whose length does not reach the free end of the drive shaft (21). Since the first orifice (31) has a larger flow path cross-section than the leakage orifice (33), the pressure drop is small, and therefore the damping force is greater than in the case shown in Figure 10 for the intermediate control law. In addition, for the same reasons as described above, the fluid continues to circulate through the conduit (28) without any further restrictions.

[0081] Figure 12 shows a graph illustrating the change in damping force in response to the extension motion of the shock absorber shown in Figure 1, with respect to the speed of the piston (4). This graph shows the gradual application of force during the operation of the shock absorber according to different control laws applied from hard to ultra-soft. Here, the important effect is that a floating piston (13) made of elastic material is provided, and its deformability brings about a gradual transition between damping at low speeds and damping at medium speeds before the opening of the primary valve (14), thus avoiding the abrupt opening of the primary valve (14) which would result in a steep change in the gradient shown by the dashed line. This mechanism makes it possible to achieve a gradual increase in damping force while more effectively eliminating irregularities in the terrain, minimizing the risk of peak chassis acceleration and noise, and further improving comfort.

[0082] For low-speed operation of the piston (4), the present invention allows for the selection of different levels of damping force through fixed permanent leakage and variable permanent leakage. Fixed permanent leakage may or may not be included through a relief disc in the valve, and variable permanent leakage is enabled or disabled according to a damping control law defined by the drive shaft (21) and the first orifice (31) and the leakage orifice (33) on the one hand, and the second orifice (32) and the axial orifice (36) on the other hand, as inlet and outlet orifices for the fluid from the piston pin (30) in the compression phase, respectively. Modification of the fixed flow path in the piston (4) also partially affects the damping force for low-speed compression operation of the piston (4), as shown in the curve in Figure 12.

[0083] For medium and high-speed operation of the piston (4), the drive shaft (21) drives or dedrives the oil flow toward the adjuster (12) to increase or decrease the level of damping force from the opening of the primary valve (14) at an approximately equal gradient for all inclines.

[0084] In the case of a shock absorber that operates in both expansion and contraction, such as the one shown in Figure 2, the change in damping force according to the speed of the piston (4) is shown in Figure 13, where the case of compression is very similar to the case of extension.

[0085] Figure 14A shows a new embodiment of the shock absorber of the present invention, which is provided with a mechanical stop for the rotational motion of the drive shaft (21). This modification affects the axial orifice (36) of the piston pin (30) and the drive shaft (21).

[0086] On the other hand, the free end of the drive shaft (21) has a vertical extension (24) in which the cross-section changes from a circular cross-section to a semicircular cross-section, and the cross-section is reduced by half.

[0087] On the other hand, the axial orifice (36) is modified at the free end, changing from a circular cross-section to an end orifice (37) having a configuration defined by an orifice with an elongated and eccentric cross-section.

[0088] The end orifice (37) has a length such that it accommodates at least a portion of the extension (24) of the drive shaft (21). Thus, the movement of the drive shaft (21) is limited to 90°, or a quarter turn, because the wall of the end orifice (37) acts as a mechanical stop, preventing further forward movement of the extension (24). This is illustrated in section AA, which is shown at two different moments in the rotation of the drive shaft (21), where the rotation of the drive shaft (21) is limited so that the buffer can only transition from a hard control law to an intermediate control law, or vice versa, i.e., only from the situation shown in Figure 4 to the situation shown in Figure 5.

[0089] This structure is advantageous because of its simplicity and because the position of the orifice of the piston pin (30) relative to the flow path of the drive shaft (21) can be controlled by the actuator (20), which is the same component.

[0090] Figure 14B shows another embodiment of the shock absorber of the present invention, which includes an angle locking system consisting of a rotation limiting plate (45) at the base of the drive shaft (21), where the window limiting the rotation of the drive shaft (21) has a geometric shape of three-quarters of a circle. The drive shaft (21) is ground, and a flat surface is formed at the end cross section, which has a suitable semicircular cross section that allows 90° rotation within the window of the rotation limiting plate (45). This plate may be a separate element or may be incorporated into the actual actuator body (23). In addition, a separation bush (46) is provided between the sealing gasket (26) and the rotation limiting plate (45). In this embodiment, it can be seen that the drive shaft (21) is shown shorter because the second orifice (32) is moved upward in the piston pin (30). The flat surface (48) of the piston pin (30) extends until the access passage (40) of the adjuster (12) is reached.

[0091] In any embodiment of the present invention, the flat surface (48) of the piston pin (30) has the function of absorbing axial dimensional variations caused by part tolerances, as well as axial dimensional variations mainly caused by the number and thickness of the piston (4) valves.

[0092] Figure 15 also shows the evolution of the mechanical stop shown in Figure 14. This evolution involves modifications made to both the axial orifice (36) of the piston pin (30) and the drive shaft (21), the difference being that the extension (24) becomes a modified extension (25) instead of having a semicircular cross-section, which here has the shape of a quarter circle, i.e., two flat surfaces. In this configuration, the modified extension (25) of the drive shaft (21) does not act as a mechanical stop against the wall of the end orifice (37) and can continue to rotate for another quarter turn, at which point it actually acts as a mechanical stop again, limiting the rotational movement. This operation is shown in the diagram of Figure 15, where the position of the modified extension (25) relative to the end orifice (37) is shown in three bottom views.

[0093] Thus, the position of the buffer can be controlled using three types of hard, intermediate, and soft control laws.

[0094] A mechanism consisting of a disk (39) and a spring (38) is introduced to control a 90° rotation, i.e., the position according to the intermediate control law. The disk (39) is attached to a piston pin (30) by a tab, and the spring (38) is compressed in a predetermined position. The compression of the spring (38) generates a controlled contact force between the disk (39) and the piston pin (30), which in turn generates a controlled torque for rotation due to friction.

[0095] As shown in Figure 15, the corrective extension (25) collides with the crescent-shaped window of the disk (39) when it rotates from 0° to 90°. This contact introduces an additional calibrated load to the actuator (20), which manifests as an increase in power consumption, and this can be detected and its shutdown recorded.

[0096] When the shaft is rotated to 180°, the disc (39) is dragged, and its crescent-shaped window allows for 90° of free rotation until it reaches 180°. Then, when it returns to the 90° position, the shaft moves freely, and when it reaches the desired position, the increased load due to the shaft's contact with the disc (39) is detected again. In this way, three angular positions of the drive shaft (21) can be controlled, two of which are controlled by fixed mechanical stops and the third by a rotational stop.

[0097] Finally, it should be noted that the present invention is not to be limited by the embodiments described herein. Those skilled in the art can carry out other configurations based on this specification. Accordingly, the scope of the present invention is defined by the following claims.

[0098] The following is a list of the symbols used in the drawings. [Explanation of symbols]

[0099] 1 Outer Case 2 Inner Tubes 3 rods 4 pistons 5 lateral chamber 6. Pressure side chamber 7. Compensation Chamber 8. Oil level 9 Gas 10 Oil 11 Compression valve 12 Adjustment body 12' Additional adjustments 13 Floating Piston 13' Additional floating piston 14 Primary valve 15 Secondary valve 15' Additional secondary valve 16 First channel 17 Second channel 18 Third channel 20 Actuators 21 Drive shaft 22 Actuator Cable 23 Actuator body 24 Extensions for two positions 25 Extensions for three positions 26 First Seal 27 The second seal 28 Conduit 30 piston pins 31. First Orifice 32. Second Orifice 32' Additional second orifice 33 Leakage orifice 34. Second leakage orifice 35 Third leakage orifice 36 Axial orifice 37 End orifice 38 springs 39 discs 40 Access Channels 41 Adjustment chamber 42 Main fixed flow path 43 Secondary fixed flow path 44 Adjustment case 45 rotation limit plate 46 Separation bush 47 slides 48. Flat surface of the piston pin

Claims

1. A regulator (12) having a primary valve (14) and a secondary valve (15), A shock absorber having multiple damping control rules, comprising a drive shaft (21) having multiple flow paths (16, 17), The drive shaft (21) is housed in an axial orifice (36) of a piston pin (30) which has a plurality of orifices (31, 32, 33) intended to be aligned with the flow paths (16, 17) by the rotation of the drive shaft (21) to determine the damping control law. The plurality of orifices include at least a second orifice (32) that communicates directly with the adjusting body (12), The buffer having multiple damping control rules is characterized in that the adjusting body (12) has an annular structure and is made of an elastic material, and includes a floating piston (13) that gradually transmits force to the primary valve (14) in accordance with the pressure it receives.

2. The plurality of orifices include at least a first orifice (31) that connects the extension chamber (5) and the axial orifice (36), The flow paths (16, 17) of the drive shaft (21) are A first flow path (16) having a length that connects the first orifice (31) and the second orifice (32), and A second flow path (17) having a length that connects the first orifice (31) and the free end of the drive shaft (21). A buffer having multiple damping control laws as described in claim 1, characterized in that it is configured as follows.

3. The plurality of orifices (31, 32, 33) A first orifice (31) connects the extension chamber (5) and the axial orifice (36) of the piston pin (30), The second orifice (32) connects the axial orifice (36) of the piston pin (30) and the compression chamber (6) through the adjusting body (12), and A leakage orifice (33) connects the extension chamber (5) and the axial orifice (36) of the piston pin (30). A buffer having multiple damping control laws as described in claim 1, characterized in that it is configured as follows.

4. The plurality of orifices include at least one leakage orifice (33) that connects the extension chamber (5) and the axial orifice (36), The buffer having multiple damping control rules according to claim 1, characterized in that the piston pin (30) is positioned as an extension of the leakage orifice (33) and has a second leakage orifice (34) having a larger flow path cross-section.

5. A shock absorber having multiple damping control rules according to Claim 1, comprising a slide (47) positioned between the flexible floating piston (13) and the primary valve (14), wherein the slide (47) is slidable along the piston pin (30), has a diameter such that it can be configured to transmit the force received from the floating piston (13) to the primary valve (14), and also has a function to protect the floating piston (13).

6. A shock absorber having multiple damping control laws according to Claim 1, comprising two adjustment bodies (12) one on each side of the piston (4), thereby enabling operation according to different damping control laws for expansion and contraction.

7. A shock absorber having multiple damping control rules according to claim 1, comprising an actuator (20) housed in the rod (3) of the piston (4) and driven by a cable (22), and attached to the drive shaft (21), wherein the selection of the damping control rule is performed automatically.

8. A shock absorber having multiple damping control rules according to claim 1, characterized in that it comprises a rod attached as an extension to the drive shaft (21), thereby allowing the selection of the damping control rule to be performed by manual operation.

9. The shock absorber having multiple damping control rules according to claim 1, characterized in that the free end of the drive shaft (21) is provided with a longitudinal extension (24) having a semicircular cross-section, and the axial orifice (36) is provided with an end orifice (37) having an elongated cross-section eccentric to the drive shaft (21), thereby limiting the movement of the drive shaft (21) to a quarter turn because the wall of the end orifice (37) acts as a mechanical stop together with the extension (24) of the drive shaft (21).

10. The rotation limiting plate (45) has a window portion having a geometric shape that is three-quarters the size of a circle, The cross-section of the end face of the drive shaft (21) for attachment to the actuator (20) has a semicircular cross-section and passes through the window portion of the rotation limiting plate (45), The shock absorber having multiple damping control rules according to claim 7, characterized in that the rotation of the drive shaft (21) is limited to a maximum of 90°.

11. The extension (24) of the free end of the drive shaft (21) is a modified extension (25) having a quarter circular cross-section, The piston pin (30) is fixed to the end, pressed by a spring (38), and includes a disk (39) having a semicircular orifice through which the corrective extension (25) passes. This shock absorber having multiple damping control rules, as described in claim 1, is characterized in that the free movement of the drive shaft (21) is limited to a quarter rotation, and the disk (39) can be rotated a further quarter rotation by dragging it against the friction generated by the pressure of the spring (38).

12. A buffer having multiple damping control rules according to claim 1, further comprising an additional adjusting body (12') arranged in connection with the adjusting body (12), wherein the adjusting body (12) is connected to the second orifice (32), and the additional adjusting body (12') is connected to an additional second orifice (32').

13. The shock absorber having multiple damping control rules according to claim 12, characterized in that the additional adjusting body (12') is located at a position further away from the extension chamber (5).

14. The plurality of orifices include at least a first orifice (31) that connects the extension chamber (5) and the axial orifice (36), The shock absorber having multiple damping control rules according to claim 12, characterized in that the drive shaft comprises a third flow path (18) having a length that connects the first orifice (31) and the two outlet orifices (32, 32').

15. The plurality of orifices include at least a first orifice (31) that connects the extension chamber (5) and the axial orifice (36), A buffer having multiple damping control laws according to any one of claims 12 to 14, characterized in that the piston pin (30) comprises a third leakage orifice (35) having a smaller flow path cross-section than the first orifice (31).

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