Valve assembly for shock absorbers

Abstract

This disclosure relates to a valve assembly for a shock absorber. The valve assembly includes: a valve housing including a first port and a second port; a pilot chamber in fluid communication with the first port and / or the second port, a pilot pressure determined by hydraulic pressure in the pilot chamber; and a main valve member axially movable within the valve housing along a longitudinal axis to restrict the main fluid flow between the first port and the second port in response to the pilot pressure acting on the main valve member. Furthermore, the main valve member is elastically loaded in a steady-state position, from which it is movable in two directions along the longitudinal axis and configured to move away from the pilot chamber during an initial pressure increase in the main fluid flow. The invention also relates to a method for controlling the flow of damping medium in a shock absorber.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 202280013665.9. That Chinese Patent Application is based on International Application PCT / EP2022 / 053118, filed on February 9, 2022, and entitled "Valve Assembly for Shock Absorber". Technical Field

[0002] This invention relates to a valve assembly for a shock absorber, used to regulate the flow of damping medium between the damping chambers of the shock absorber, and particularly to a valve assembly for preventing overshoot. Background Technology

[0003] The valve assembly in the vehicle absorbs some of the vibrations from the damper without transmitting them to the chassis, thus making the ride smoother.

[0004] State-of-the-art valve assemblies for vehicles such as automobiles or motorcycles can be electrically controlled, as shown in EP18157676. In a shock absorber including a pilot valve, a pressure regulator (i.e., the valve assembly) controls the flow of the damping medium between the compression and rebound chambers during the reciprocating motion of a piston in the damping medium-filled chamber of the shock absorber. The piston is connected to a wheel or chassis via a piston rod, while the chamber is connected to one of the wheels or chassis not connected to the piston. During the compression stroke, the piston moves axially toward the compression chamber, thereby pressurizing the damping medium in the compression chamber. During the rebound stroke, the piston moves axially toward the rebound chamber, i.e., in the opposite direction, thereby pressurizing the damping medium in the rebound chamber.

[0005] The pressure of the damping medium flow in a shock absorber is controlled by a valve assembly. The pressure regulator in a shock absorber typically has an axially movable or deflectable valve member, such as a washer, coil, or shim, that acts on a valve seat portion. Pressure control is achieved through the balance of forces, for example, the balance between the pressure and / or flow rate acting on the valve member in one direction and the counteracting or opposing forces acting on the valve member in the opposite direction, such as one or more spring forces, frictional forces, and pilot pressures. When the piston of the shock absorber moves at a certain speed, causing the pressure and / or flow force to exceed the reaction force or counteracting force, the movable valve member is forced away from the valve seat portion, thereby opening the flow passage. Therefore, the movable valve member is forcibly opened, and its stroke is defined as a function of the flow rate generated by the pressure acting in the regulating zone of the pressure regulator.

[0006] One challenge in pilot-operated pressure control valve manifolds is reducing overshoot caused by the initial pressure increase in the pilot chamber when the manifold initially opens. This overshoot typically has a negative impact on damping characteristics.

[0007] Therefore, it is necessary to provide an improved valve assembly for the shock absorber to alleviate the overshoot problem. Summary of the Invention

[0008] The object of this invention is to provide an improved solution to alleviate the aforementioned drawbacks of existing solutions. Furthermore, the object of this invention is to provide a method for controlling a valve assembly that can also alleviate the overshoot problem of the aforementioned shock absorber.

[0009] This invention is based on the inventors' understanding that the aforementioned objectives can be achieved by incorporating a valve assembly designed and functional to allow for an initial increase rather than a decrease in pilot chamber volume, thereby mitigating overshoot problems. Testing has also shown that this valve assembly can reduce the harshness of noise and vibration, thereby increasing secondary comfort on the road.

[0010] According to a first aspect of the invention, a valve assembly for a shock absorber is provided. The valve assembly includes: a valve housing including a first port and a second port; and a pilot chamber in fluid communication with the first port and / or the second port. Furthermore, a pilot pressure is determined by hydraulic pressure in the pilot chamber. The valve assembly also includes a main valve member that is axially movable along a longitudinal axis within the valve housing and arranged to interact with a main valve seat of the valve housing to restrict the main fluid flow between the first port and the second port in response to the pilot pressure acting on the main valve member. The valve assembly is characterized in that the main valve member is elastically loaded in a steady-state position from which it can move in two directions along the longitudinal axis and is configured to move away from the pilot chamber during an initial increase in the pressure of the main fluid, thereby increasing the volume of the pilot chamber.

[0011] The valve assembly further includes an axially movable valve seat member axially arranged between the main valve member and the main valve seat, wherein the axially movable valve seat member includes a first limiter and a second limiter arranged in series therewith, wherein a first orifice of the first limiter and a second orifice of the second limiter are controlled by the axial position of the main valve member relative to the valve housing.

[0012] Therefore, a soft-opening valve assembly is provided to mitigate overshoot because the increased pilot chamber volume, together with the elastically loaded main valve component, provides a soft-opening damper without adding force.

[0013] When the main valve component moves away from the pilot chamber to increase its volume, the main valve component moves out of the steady-state position and into the pre-tightened position balanced by the pressure of the pilot chamber.

[0014] In one embodiment, the first limiter is positioned upstream of the main fluid flow in the compression stroke relative to the second limiter.

[0015] In a further embodiment, during the compression stroke, the first orifice of the first limiter is always smaller than the second orifice of the second limiter. Therefore, the limiting effect of the second limiter will be less than that of the first limiter alone.

[0016] In one embodiment, the first limiter is at least a partial circumferential hole between the movable valve seat member and the main valve seat.

[0017] In a further embodiment, a second limiter is arranged radially outside the first limiter in at least a partially circumferential orifice between the movable valve seat member and the main valve seat.

[0018] In one embodiment, the first limiter is radially spaced from the second limiter via a circumferential hole on a movable valve seat member.

[0019] In a further embodiment, the main valve seat includes a circumferential bore aligned with a circumferential bore in a movable valve seat member.

[0020] In one embodiment, the valve assembly further includes at least one gasket disposed between a main valve member and a movable valve member in the initial flow path.

[0021] In a further embodiment, at least one gasket is configured to deflect in response to an increase in pressure in the main fluid flow, thereby allowing initial fluid flow between the first port and the second port.

[0022] In one embodiment, the valve assembly further includes a third limiter connected in series with the second limiter, wherein the third limiter has a constant orifice that is independent of the axial position of the main valve member relative to the valve housing.

[0023] In one embodiment, the third limiter has an orifice directly connected to the orifice of the first limiter. In one embodiment, the pressure region in the pilot valve chamber is greater than the pressure region of the main valve member in the closed position. Therefore, when the pressure in the pilot chamber is substantially the same as the pressure on the other side of the main valve member, the main valve member moves away from the pilot chamber. This area difference creates a preload on the main valve member. Once the main valve member moves away from the valve seat, allowing fluid flow between the first and second chambers, the pressure drops.

[0024] In the context of this application, initial pressure increase refers to the increase in pressure of the main fluid from the first port before any flow of the main fluid is permitted between the first and second ports.

[0025] In the context of this application, the main valve component being "arranged to interact with the main valve seat" means that the position of the main valve component relative to the main valve seat will restrict the main fluid flow between the first port and the second port. The main valve component and the main valve seat do not necessarily interact directly, but can (as shown) interact through intermediate components such as gasket assemblies.

[0026] In the context of this application, "elastically loaded in a steady-state position" should be understood as a component in such a position requiring a force (e.g., fluid pressure) to move out of that position, and as the component moves, the elastic load on the component increases toward the steady-state position.

[0027] In one embodiment, the main valve component is configured to move toward the pilot chamber to reduce the volume of the pilot chamber when the pressure of the main fluid flow exceeds a predetermined value above the initial pressure increase.

[0028] Therefore, when the pressure exceeds a predetermined value, the movement of the main valve component will have a reverse motion. This value can be selected / configured by choosing a resilient component such as a gasket, gasket set, or coil (or a combination thereof) and a pressure zone on the main valve component, such that a specific pressure from the main fluid will produce the aforementioned motion. Further details in this regard will be provided in the appendix of the detailed description. Figure 1 To explain.

[0029] In one embodiment, the predetermined value is selected as the pressure level corresponding to when the main valve component begins to move to allow the main fluid to flow to the second port.

[0030] In another embodiment, both the initial pressure increase and the predetermined value occur during the main fluid pressure increase from the first port.

[0031] In one embodiment, the main valve member is elastically loaded by a first spring device on a first side of the main valve member and a second spring device on a second side of the main valve member opposite to the first side.

[0032] Therefore, spring devices (such as helical springs and / or gaskets or elastic components, such as any kind of flexible material) can be selected to apply a specific steady-state position and / or load to the main valve component.

[0033] In another embodiment, the first spring device is at least one washer. In one embodiment, it is a group of washer pieces. In one embodiment, the second spring device is a helical spring.

[0034] In one embodiment, a first spring device is arranged between the main valve member and the main valve seat. Therefore, the spring device can apply a spring force away from the main valve seat.

[0035] In another embodiment, the main valve component includes a pressure region that exposes the pilot chamber, which is greater than the pressure region acting on the axially opposite side of the main valve component when the main valve component is in the steady-state position.

[0036] Therefore, during the initial pressure increase, the main valve components can move towards the main valve seat to increase the volume of the pilot chamber.

[0037] In one embodiment, the main valve assembly includes a bypass passage that fluidly connects the first port to the pilot chamber. Therefore, fluid can be transferred from the first port to the pilot chamber, and the pressure is substantially equal on both sides of the main valve assembly. The size of the bypass passage determines the hysteresis of the pressure increase in the pilot chamber compared to the pressure increase at the first port.

[0038] In one embodiment, the pilot pressure is actively controlled by an electric actuator such as a solenoid or stepper motor. Therefore, the valve assembly can allow for actively controlled damping characteristics, as in vehicles, for example.

[0039] In one embodiment, the pilot pressure is controlled by a fail-safe mechanical spring valve when the actuator current is below a threshold. In another embodiment, the pilot pressure is controlled by a fail-safe mechanical spring valve when the actuator current is below 0.2 amps. Therefore, if any component fails, the pilot pressure is still controlled, but via the mechanical spring valve. Even with an electrical component failure, the current is typically not zero due to the presence of quiescent and / or induced currents.

[0040] In another embodiment, the main valve member moves away from the pilot chamber during the initial pressure increase, with a stroke length of approximately 0.05-0.5 mm, preferably approximately 0.1 mm, at which point it changes direction and moves back towards the pilot chamber. Therefore, only the initial portion of the movement is reversed, allowing the main valve member to move in the opposite direction after the initial movement.

[0041] In one embodiment, the valve assembly further includes a calibration shim for calibrating the maximum load of the first spring assembly. Therefore, the position of the spring assembly (such as the shim) can be controlled by axial movement to adjust the maximum load.

[0042] According to one aspect of the invention, a shock absorber comprising at least one valve assembly according to any of the embodiments described herein can be provided. Thus, a shock absorber that mitigates overshoot problems can be provided. Such a shock absorber can be implemented in vehicles, such as automobiles, motorcycles, vans, trucks, or other vehicles equipped with shock absorbers.

[0043] According to one aspect of the invention, the above-mentioned problem is alleviated by at least one method for controlling the flow of damping medium between the damping chambers of a shock absorber via a valve assembly, the valve assembly comprising: a valve housing including a first port and a second port; a pilot chamber in fluid communication with the first port and / or the second port, wherein a pilot pressure is determined by hydraulic pressure in the pilot chamber; and a main valve member axially movably disposed within the valve housing and arranged to interact with a main valve seat of the valve housing to restrict the main fluid flow between the first port and the second port in response to the pilot pressure acting on the main valve member. The method includes the following steps: - Elastically loads valve components in a steady-state position, and -During the initial pressure increase of the main body, the main valve assembly is moved away from the pilot chamber to increase the volume of the pilot chamber.

[0044] The method further includes the step of moving the main valve member toward the pilot chamber when the pressure of the main fluid flow exceeds a predetermined value above the initial pressure increase, thereby subsequently reducing the volume of the pilot chamber. The final step of the method is, in active flow control mode, to restrict the main fluid flow at the first and second limiters by controlling the first orifice of the first limiter and the second orifice of the cooperating, tandemly arranged second limiter by controlling the axial position of the main valve member relative to the valve housing.

[0045] The advantages of this method are largely similar to those described in the combined valve manifold, providing a soft-opening valve manifold that mitigates overshoot and offers damping characteristics with improved dynamic properties.

[0046] Any embodiment or feature described in terms of the device can have a corresponding function in the method, and vice versa. Therefore, the different aspects of the invention form a single inventive concept that can be combined in any way, provided the embodiments are compatible.

[0047] The invention is defined by the appended independent claims, and some preferred embodiments are set forth in the appended dependent claims, the following description, and the accompanying drawings. Attached Figure Description

[0048] The present invention will now be described in more detail with reference to the accompanying drawings, wherein: Figure 1 A cross-sectional view of a valve assembly according to an embodiment of the present invention is shown. Figure 2a A side view of a shock absorber with two valve assemblies is shown. Figure 2b A side view of a shock absorber with a single valve assembly is shown. Figure 3aAn overview of a valve assembly according to an embodiment of the present invention is shown. Figure 3b An exploded perspective view of a valve assembly according to an embodiment of the present invention is shown. Figure 4a An overview of a main valve assembly according to an embodiment of the present invention is shown. Figure 4b An exploded perspective view of a main valve assembly according to an embodiment of the present invention is shown. Figure 5a - 5c shows cross-sectional views of a valve assembly at different locations according to an embodiment of the present invention. Figure 6a An overview of a main valve assembly according to an embodiment of the present invention is shown. Figure 6b An exploded perspective view of a main valve assembly according to an embodiment of the present invention is shown. Figure 7 A cross-sectional view of a valve assembly according to an embodiment of the present invention is shown. Figure 8 A flowchart of a method for controlling damped fluid flow according to one embodiment is shown. Figure 9 The diagram showing the relationship between the axial position of the main valve component and the system pressure is shown. Figure 10 The graph showing the relationship between the main fluid flow and the system pressure is shown. Figure 11a An exploded perspective view of a main valve component according to an embodiment of the present invention is shown. Figure 11b An exploded perspective view of a main valve assembly according to an embodiment of the present invention is shown. Figure 12a - 12d shows a cross-sectional view of a valve assembly at different locations according to an embodiment of the present invention. Figure 13a A graph showing the relationship between orifice opening and stroke length is provided. Figure 13b The diagram shows the movable valve seat component and the first, second, and third orifices for a given stroke length S. Detailed Implementation

[0049] The invention will now be described more fully with reference to the accompanying drawings, which illustrate preferred embodiments of the invention. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the disclosure of the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, similar numerals refer to similar elements.

[0050] Figure 1 A cross-sectional overview view of a valve assembly 1 according to an embodiment of the present invention is shown. The valve assembly includes a valve housing 2 having a first port 7 and a second port 8. The valve assembly is configured to control the main fluid flow between the first port 7 and the second port 8. Furthermore, the figure shows that the valve assembly includes a pilot chamber 3 in fluid communication with the first port 7 and the second port 8. The pilot chamber is adapted to hold fluid at a pilot pressure PP, which is defined by hydraulic pressure within the pilot chamber. Additionally, the valve assembly includes a main valve member 4, which is axially movable along a longitudinal axis A passing through the central portion of the valve housing 2. The main valve member is configured to interact with a main valve seat 9 of the valve housing to restrict the main fluid flow 21 between the first port 7 and the second port 8. Figure 5c (As shown). The main fluid flow is regulated based on the pilot pressure PP acting on the main valve component.

[0051] Furthermore, the main valve component 4 is elastically loaded in the steady-state position (e.g., Figures 5a-5c and Figure 7 As shown), from there it can move in two directions along the longitudinal axis (A). In the steady state, the main fluid flow cannot pass between the first port and the second port.

[0052] Figure 2a and Figure 2b Side views of a shock absorber 100 with two valve assemblies and one valve assembly are shown respectively. Figure 2a and Figure 2b In this context, these two valve assemblies are typically used by fluidly coupling one valve assembly to the fluid flow during the compression stroke and the other to the fluid flow during the rebound stroke. Both 1a and 1b can be the valve assemblies described herein, featuring a bidirectional main valve component; however, in some embodiments, the valve assembly can be combined with another type of valve assembly. Figure 2b In this context, valve assembly 1a can be a two-way valve assembly used to handle flow in two directions, namely fluid flow during the compression stroke and the rebound stroke.

[0053] Figure 3a and Figure 3b An overview of valve assembly 1 and an exploded perspective view of the valve assembly are shown. The valve assembly includes a cylindrical valve housing 2 with a first port 7 (not shown in the perspective view) and a second port 8. In this embodiment, the second port includes several orifices, so that fluid flow can flow radially outward around the cylinder.

[0054] The valve assembly also includes a fail-safe gasket 33, which functions as a check valve together with a pilot gasket spring 31, which serves as the seat of the check valve. In this embodiment, the gasket spring 31 includes several spring portions for generating different spring forces during different strokes of the actuator 5 acting on the spring. This is in Figures 5a-5cThe cross-sectional view is the easiest to understand.

[0055] The exploded view further illustrates the cylindrical shape of the main valve component, as well as the calibration gasket 6 and the valve seat portion 9.

[0056] Figure 4a and Figure 4b The main valve body is described in further detail, with 4a showing an overview of the main valve assembly, while Figure 4b An exploded perspective view of the main valve assembly is shown. Similarly, these figures should be understood as possible embodiments of the invention, and not necessarily the only way to implement the inventive concepts defined in the claims.

[0057] The main valve assembly 4 includes a central body 41 with an elongated cylindrical shape, the circumference of which of its head 47 is larger than the rest of the central body. The head 47 includes an orifice 49 for allowing damped fluid to flow between the upper and lower portions of the pilot chamber 3. A helical spring 43 is positioned around the central body 41 and sandwiched between the head 47 of the central body and the outer body 42 of the main valve assembly. This helical spring is used to preload the main valve assembly in an axial direction away from the pilot chamber 3.

[0058] Figure 4b Further description includes a gasket assembly with three gaskets 44a, 44b, and 44c, and a locking element in the form of a locking washer 46, used to lock the central body 41, such that the gasket assembly is clamped between the locking washer 46 and the outer body 42. The gasket assembly may include more or fewer gaskets with different thicknesses and gaps, thereby adjusting, for example, its elasticity.

[0059] Figures 5a-5c A cross-sectional view of a valve assembly according to an embodiment of the present invention is shown, wherein the main valve component is in different axial positions. Figure 5a In this configuration, the main valve component is in its steady-state position SSP. In this position, the helical spring component 43 can preload the main valve component toward the main valve seat 9, while the gasket assembly 44 (including gaskets 44a, 44b, and 44c) preloads the main valve component away from the main valve seat 9. Alternatively, the helical spring component and / or the gasket assembly 44 may not preload the main valve component until the main valve component moves out of its steady-state position.

[0060] exist Figure 5a The document also explains how actuator 5 acts on pilot washer spring 31 to control pilot pressure. Actuator 5 can be connected to a solenoid or stepper motor, allowing the position or force of the actuator to be controlled via software.

[0061] The axial position of the main valve component 9 is determined by the thickness of the calibration gasket 6. The calibration gasket therefore also determines the preload of the gasket assembly 44.

[0062] The outer body 42 includes a bypass channel 48, allowing a bypass flow 22 between the first port 7 and the pilot chamber 3. In this configuration, the size of the bypass channel determines the lag in the pressure increase in the pilot chamber compared to the pressure increase at the first port.

[0063] Several moving components depend on a series of spring mechanisms and hydraulic pressure. Once the preload force of the helical spring 43 is reached, relative movement occurs between the outer body 42, the gasket assembly, and the central body 41, with the outer body moving in the positive X direction. This is in Figure 5c This was explained in the text. However, prior to this, when the gasket assembly undergoes elastic deformation under increased hydraulic pressure, a relative movement occurs between the main valve body 43 and the valve housing 2 in the negative X direction. This produces an inverted motion, where the displacement of the main valve components initially expands the volume of the pilot chamber.

[0064] exist Figure 5b When the predetermined pressure is reached, the outer body 42 of the main valve component 4 moves along the negative axial direction, that is, downwards in the figure, away from the pilot chamber and towards the main valve seat 9. This occurs during the initial pressure increase of the main body, thereby increasing the volume of the pilot chamber 3.

[0065] This valve assembly can be used for system pressures from 1 to 400 bar. Preset values ​​can be selected depending on the application to reduce overshoot in specific applications.

[0066] When turning Figure 5c At this time, the hydraulic pressure increases further, thereby reaching the preload force of the helical spring 43, the outer body 42 moves in the positive X direction, and the main fluid flow 21 is allowed between the first port 7 and the second port 8.

[0067] The pressure zone on the outer body 42 is larger in the pilot chamber than on the other side of the outer body 42. Therefore, the pressure in the pilot chamber will generate a preload force on the gasket assembly 44 through the outer body 42.

[0068] It is the bypass channel 48 in the outer body 42 that pressurizes the main valve component against the first spring device.

[0069] Figure 6a , Figure 6b and Figure 7 An embodiment of the invention is illustrated, in which a movable valve seat member 10 is used. The movable valve seat 10 includes a first circumferential bore 11, and the valve seat portion 9 also includes a circumferential bore 12 that mates with the first circumferential bore 11. The two circumferential bores 11 and 12 together create the soft-opening function of the valve.

[0070] exist Figure 6a , Figure 6b and Figure 7 In the middle, the central body 42 has been replaced by the top body 41b, which has a hole to receive and fix the helical spring 43. Figure 6a , Figure 6b and Figure 7 The embodiments described herein have the same function as those described above, but are included to illustrate that the invention can be designed in different ways without departing from the concept of the invention.

[0071] also, Figure 8 A simplified flowchart of a method for controlling the flow of damping fluid according to one embodiment is shown. The method is used to control the flow of damping medium between the damping chambers 7 and 8 of a shock absorber 100 via the valve assembly 1 described in any of the above embodiments. The method includes the following steps: S1, elastically loading the valve member 4 in a steady-state position. As described above, this can be accomplished, for example, by placing the main valve member between spring devices (e.g., a coil spring or shims, or a combination thereof). In the most typical example here, shims or shim assemblies are used as the first spring device to generate a load away from the main valve seat, while the coil spring is used to generate a load towards the main valve seat.

[0072] As a second step S2, the method includes moving the main valve component 4 away from the pilot chamber 3 during the initial pressure increase of the main body, thereby increasing the volume of the pilot chamber. This can be achieved in various ways, but by doing so, the damping medium can be controlled without the overshoot problem typical of the prior art.

[0073] The third step S3 is performed, which is that when the pressure of the main fluid flow exceeds a predetermined value higher than the initial pressure increase, the main valve component 4 is moved toward the pilot chamber 3, thereby subsequently reducing the volume of the pilot chamber.

[0074] Subsequently, in active flow control mode, the fourth step S4 is executed, which involves controlling the first orifice OR1 of the first restrictor R1 and the second orifice OR2 of the second restrictor R2 arranged in series therewith by controlling the axial position of the main valve member 4 relative to the valve housing 2, thereby restricting the main fluid flow at the first restrictor and the second restrictor R2. This step is preferably performed by energizing, for example, a solenoid or stepper motor that controls the axial position of the main valve member 4. The axial position can be controlled by combining the control solenoid or stepper motor with a pilot pressure acting on the main valve member 4.

[0075] It will be apparent to those skilled in the art that the device-related functions described herein can also be incorporated into the method. For example, the bypass flow path 48 described in the outer body 42 also discloses the step of pressurizing the main valve component to the first spring device via the bypass flow.

[0076] at last, Figures 9 to 10These are two diagrams illustrating the location and fluid flow related to system pressure in the hydraulic shock absorber described in this article. As a starting point, the shock absorber can be summarized as handling two types of motion. First, there is the motion from the vehicle chassis, typically with frequencies in the 1-3 Hz range. Second, there is motion from road unevenness, which is typically higher frequency motion, such as 10-200 Hz.

[0077] exist Figure 9 and Figure 10 In this diagram, valve position and main fluid flow are described under three low-frequency (also known as static level, essentially less than 10 Hz) and three high-frequency (also known as dynamic level, essentially greater than 10 Hz) conditions. These three conditions represent high current, fail-safe, and low current being supplied to the solenoid of the control actuator 5.

[0078] from Figure 9 It begins by showing a graph relating the axial position of the main valve assembly to the system pressure. As can be seen from this graph, the main valve assembly first moves from a first position X1, corresponding to the steady-state position of the main valve assembly, to a second position X2, and then turns in the positive direction once the system pressure increases above a predetermined level. As explained in these graphs, the predetermined level depends on the current supplied to the solenoid, and thus on the actuator acting on the pilot pressure. When the motion to be absorbed by the damper is high-frequency, the main valve assembly will not have time to move as far as the negative (X2) position, and then it turns in the positive direction, thus opening the main fluid flow.

[0079] like Figure 10 As shown, the result of these three scenarios is that, in the initial stage of system pressure increase, the main flow rate Q is essentially zero. The system pressure at the start of fluid flow depends on the current input to the solenoid controlling the actuator force. From Figure 10 It can be seen that the overshoot problem that usually occurs in high-frequency damping processes is fundamentally alleviated. In contrast to the overshoot problem, due to the reversal of the initial movement of the main valve components, the main fluid flow will never overshoot; on the contrary, at low system pressure levels, the flow rate will be slightly lower than at low frequencies.

[0080] Therefore, in existing technologies, the pressure is typically high when the damper components do not move fast enough, resulting in overshoot. However, with this design, the pressure decreases as the frequency increases.

[0081] Figure 11a An exploded perspective view of a main valve component according to an embodiment of the present invention is shown. The main valve body includes an outer body 41c, an intermediate sleeve 41a, and an inner top body 41b. The inner top body 41b houses a helical spring 43, which, as described above, biases the main valve component.

[0082] Figure 11bAn exploded perspective view of a main valve assembly according to an embodiment of the present invention is shown. This assembly is related to... Figure 3b The components described are essentially the same, but the main difference is the inclusion of a movable valve assembly. This valve assembly includes the previously mentioned fail-safe gasket 33, which functions as a check valve in conjunction with the pilot gasket spring 31, where the pilot gasket spring acts as the seat of the check valve.

[0083] In the illustrated embodiment, the washer spring 31 includes several spring portions for generating different spring forces during different strokes of the actuator 5 acting on the spring. This is in Figures 12a-12c The cross-sectional diagram is the easiest to understand, and its logic is the same as the one described above. Figures 5a-5c The same logic is used.

[0084] The valve assembly also includes a biasing gasket 34 for biasing the main valve member 4 in a downward direction at an axial position near the top of the valve housing 2. The biasing gasket includes a hole to allow fluid flow through it.

[0085] The exploded view further illustrates the cylindrical shape of the main valve component 4. Additionally, a gasket or initial bypass gasket 13 is shown between the main valve component 4 and the movable seat valve 10. Finally, the calibration gasket 6 and the valve seat portion 9 are illustrated in the lowest part of the figure. These components are arranged coaxially.

[0086] Similarly, these figures should be understood as possible embodiments of the invention, and not necessarily the only way to implement the inventive concepts defined in the claims.

[0087] Figures 12a-12c Cross-sectional views of a valve assembly at different locations are shown according to an embodiment of the present invention. Figure 12a Corresponding to Figure 5a The state / position discussed here refers to the steady-state position. Figure 12b Corresponding to Figure 5b The state / position discussed earlier, i.e., the initial pre-tensioned state, is characterized by the expansion of the pilot chamber due to the movement of the main valve components toward the valve seat (away from the pilot chamber). Finally, Figure 12c Corresponding to Figure 5c The state / position discussed here refers to the state in which the main fluid flow 21 is restricted between the valve seat and the movable valve seat member 10.

[0088] and Figures 5a-5c Any further discussion of the details also applies. Figures 12a-12c .

[0089] exist Figure 12aIn this configuration, the main valve member 4 is in its steady-state position SSP. In this position, the biasing shim 34 can preload the main valve member 4 toward the movable valve seat member 10 (and thus also toward the main valve seat 9). Viewed from the other side, at least one shim or shim group 44 (shown above as including shims 44a, 44b, 44c) preloads the main valve member away from the main valve seat 9 via the movable valve seat 10. Alternatively, the helical spring and / or shim group 44 may not preload the main valve member until it has moved out of its steady-state position.

[0090] Figure 12a This also explains how actuator 5 acts on pilot washer spring 31 to control pilot pressure. Figures 11a to 12c The pilot washer spring 31 is a further development based on the washer spring described in the previous embodiments, and includes a third spring function. The actuator 5 can be connected to a solenoid or stepper motor, so that the position or force of the actuator can be controlled by software, as described above.

[0091] Figures 12a-12c A key difference in the embodiment is that it includes an initial channel 14 that allows initial bypass flow through an initial bypass gasket 13 from the first port 7 to the second port 8. The gasket 13, or "initial bypass gasket," is configured to allow a small initial bypass flow 23 at the first port 7 with a very small pressure increase. The majority of this initial bypass flow occurs before the pilot chamber volume increases due to the aforementioned pressure increase. Therefore, a "very small" pressure increase refers to an increase from 0 to a predetermined value in which the main valve member moves away from the pilot chamber to increase its volume. Once the main valve member reaches its lowest point, such as... Figure 12b and Figure 12c As shown, since gasket 13 is sandwiched between the main valve member 4 and the movable valve seat member 10, gasket 13 is essentially closed. However, even when gasket 13 is sandwiched between the main valve member 4 and the movable valve seat member 10, some flow still occurs. Since the gasket has virtually no moving mass, the movement of the gasket can be much faster than the axial movement of the valve assembly within the valve manifold.

[0092] The axial position of the main valve component 9 and the movable valve seat component 10 is determined by the thickness of the calibration gasket 6. The calibration gasket 6 therefore also determines the preload of at least one gasket or gasket group 44.

[0093] The movable valve seat component 10 includes a central portion 110 whose size and shape match the central bore of the main valve component 4. This central portion protrudes upward into the main valve component 4.

[0094] Alternatively, the main valve component may also include a central portion whose dimensions and configuration match a corresponding hole in the movable valve seat component 10. Thus, the central portion of the main valve component 4 will preferably protrude axially toward the movable valve seat component, i.e., toward the first port 7 in a specific embodiment. The engaging portion arranges the components coaxially.

[0095] The valve assembly includes a bypass passage 48 that allows a bypass flow 22 between the first port 7 and the pilot chamber 3. The size of the bypass passage determines that the pressure increase in the pilot chamber is lagging compared to the pressure increase in the first port. The bypass flow 22 flows from the first port into the pilot chamber and further flows to another surface of the valve body at a bypass orifice 26 outside the valve body, and then flows to the volume of the second port.

[0096] Figures 12a-12c The cross-sectional view in the diagram does not fully illustrate the second port 8 passing through the valve housing 2. The second port consists of several openings distributed circumferentially along the valve housing. Figure 11b This is also illustrated in the text. Similarly, the initial channel 14 points only at a specific opening in the movable valve seat member 10, but several openings can together form the initial channel 14.

[0097] exist Figure 12b When the first port reaches the predetermined pressure, the outer body 42 of the main valve component moves in the negative axial direction, i.e., downwards in the figure, away from the pilot chamber, and towards the movable valve seat component 10 and the main valve seat 9. This occurs during the initial pressure increase of the main body, thereby increasing the volume of the pilot chamber 3, as described above.

[0098] When turning Figure 12c At this time, the hydraulic pressure further increases, thereby reaching the preload force of the helical spring 43, the outer body 42 moves in the positive X direction (away from the main seat 9, upward in the figure), and the main fluid flow 21 is regulated between the first port 7 and the second port 8 by the first limiter R1 and the second limiter R2 in series.

[0099] The movable valve seat member 10 and / or the main valve seat member 9 include a circumferential bore 25 having a radial inner wall 25a and a radial outer wall 25b. The bore may be formed in the valve seat member 9, or in the movable valve seat member 10, or in both, with two aligned bores together forming the circumferential bore.

[0100] Connected to the radial inner wall 26 (in either or both of the movable valve seat member 10 and the main seat 9), another hole forms a third limiter R1'. The third limiter R1' allows damping fluid to enter the circumferential hole 25, thereby pressurizing the movable valve seat member 10 according to the pressure at the first port 7.

[0101] exist Figure 12cIn this state, the regulating main fluid flow 21 from the first port 7 to the second port 8 is allowed, and is first restricted by the first limiter R1 plus the fourth limiter R1' (upstream, closest to the first port), and then restricted by the second limiter R2 downstream of the first limiter R1.

[0102] At the radial inner wall 25a, the movable valve seat member 10 and the main valve 9 form part of the first limiter R1, and at the radial outer wall 25b, the movable valve seat member 10 and the main valve seat 9 form the second limiter R2.

[0103] Figure 12d These flows are illustrated more clearly by a close-up of components such as the main valve seat 9, the movable valve seat member 10, and the gasket 13, or "initial bypass gasket." The initial flow 23 is schematically shown as flowing between the movable valve seat member 10 and the gasket 13, as described above. Figure 12a The description is as follows. Furthermore, as described above, the main fluid flow 21 is described as flowing through the first restrictor R1 and the third restrictor R1' and subsequently the second restrictor R2.

[0104] In any partially open state, the first limiter R1 is smaller than the second limiter R2 because both limiters are formed as circumferential limiters and are radially displaced. Since the second limiter has a larger circumference, its orifice will always be larger than the orifice of the first limiter, forming a common dividing line upwards (movable valve seat member 10) and downwards (radial sidewalls of the main valve seat 9). Furthermore, the fourth limiter R1' has a constant opening. Therefore, the sum of the first limiter R1 and the third limiter R1' is initially larger than the second limiter R2, but as the stroke S increases, the second limiter becomes larger than the sum of the first and fourth limiters. Figure 13a and Figure 13b Further explanation is provided below.

[0105] Figure 13a Two graphs are shown showing the orifice OR1+OR1' and OR2 as functions of stroke length S. The first orifice OR1 corresponds to the orifice of the first limiter R1. This orifice OR1 is also determined by... Figure 13b The envelope of the circle in the diagram is illustrated and denoted by OR1, therefore it depends on the stroke length S. The second orifice OR2 corresponds to the orifice OR2 of the second limiter R2. Figure 13b In this diagram, the orifice is also represented by the envelope of a cylinder, denoted by OR2. The third orifice OR1' corresponds to the orifice of the third limiter R1'. This orifice OR1' is also represented by... Figure 13b The surface represented by OR1' is used to illustrate this, and it corresponds to the opening of the circumferential hole in the main valve housing 2.

[0106] Figure 13bThe simplified diagram illustrates the first orifice OR1, the second orifice OR2, and the third orifice OR1' under a given stroke length S. This diagram shows how the first orifice OR1 and the second orifice OR2 change with the stroke length S, while the third orifice OR1' remains static.

[0107] In the initial stage of regulating the main fluid flow, that is, when R1 and R2 have just opened from the closed position, the restriction will be performed in the second limiter, such as... Figure 13a As shown, this is because, in the initial stage, the orifice of the second limiter R2 is smaller than the orifice of the first limiter and the third limiter R1+R1'. Once the orifice of the second limiter R3 is larger than the combined orifice of the first limiter and the third limiter R1+R1', the restriction is applied at the first limiter + third limiter.

[0108] Without departing from the concept of this invention, the dimensional relationship between the orifices of different limiters can be varied. This can be achieved by adjusting the orifice relationship. Figure 13a The intersection point between the "OR1+OR1'" and "OR2" curves shown can be moved. The aperture of OR1' is indicated by the point where the "OR1+OR1'" curve intersects the Y-axis. Figure 13a The different inclinations of the two curves illustrate the relationship between the sizes of the orifices OR1 of the first and second limiters. Furthermore, by increasing the maximum diameter of the third orifice OR1' relative to the first orifice OR1, the soft opening is lengthened.

[0109] The diameter of the third orifice OR1' can be substantially smaller than that of the first orifice, for example, about 0.1%-10% of the maximum diameter of the first orifice OR1.

[0110] The invention can be implemented using either passive control of the main valve components, such as a spring device, or active control using an electric actuator, such as a solenoid or stepper motor. Another possibility is that the valve assembly is actively controlled, but has a backup passive spring device in case of active control failure. That is, a fail-safe mode controlled valve assembly.

[0111] Preferred embodiments and examples of the invention have been disclosed in the accompanying drawings and description. Although specific terminology has been used, it is used only in a general and descriptive sense and not for limiting purposes. The scope of the invention is set forth in the appended claims.

[0112] List of numbered embodiments 1. A valve assembly (1) for a shock absorber, the valve assembly comprising: - Valve housing (2), the valve housing includes a first port (7) and a second port (8); - Pilot chamber (3), the pilot chamber being in fluid communication with the first port and / or the second port, wherein the pilot pressure (PP) is determined by hydraulic pressure in the pilot chamber; - A main valve component (4), which is axially movable along the longitudinal axis (A) in the valve housing and arranged to interact with the main valve seat (9) of the valve housing to restrict the main fluid flow (21) between the first port (7) and the second port (8) in response to the pilot pressure acting on the main valve component; wherein - The main valve component (4) is elastically loaded in a steady-state position from which it can move in two directions along the longitudinal axis (A) and is configured to move away from the pilot chamber (3) during the initial pressure increase of the main body, thereby increasing the volume of the pilot chamber.

[0113] 2. The valve assembly according to Embodiment 1, wherein the main valve component (4) is configured to move toward the pilot chamber (3) when the pressure of the main fluid flow exceeds a predetermined value higher than the initial pressure increase, thereby reducing the volume of the pilot chamber.

[0114] 3. The valve assembly according to Embodiment 2, wherein the initial pressure increase and the predetermined value both occur during the main fluid pressure increase from the first port (7).

[0115] 4. The valve assembly according to any one of Embodiments 1 to 3, wherein the main valve member (4) is elastically loaded by a first spring device (44) on the first side of the main valve member and a second spring device (43) on the second side of the main valve member opposite to the first side.

[0116] 5. The valve assembly according to embodiment 4, wherein the first spring device (44) is at least one gasket.

[0117] 6. The valve assembly according to any one of Embodiments 4 or 5, wherein the second spring device (43) is a helical spring.

[0118] 7. The valve assembly according to any one of embodiments 1 to 6, wherein the first spring device is arranged between the main valve member (4) and the main valve seat (9).

[0119] 8. The valve assembly according to any one of Embodiments 1 to 7, wherein the main valve member includes a pressure region (45) that exposes the pilot chamber, and when the main valve member is in the steady-state position, the pressure region is greater than the pressure region acting on the axially opposite side of the main valve member.

[0120] 9. The valve assembly according to any one of embodiments 1 to 8, wherein the main valve component (4) includes a bypass passage (48) fluidly connecting the first port (7) and the pilot chamber (3).

[0121] 10. The valve assembly according to any one of embodiments 1 to 9, wherein the pilot pressure is actively controlled by an electric actuator (5) such as a solenoid or a stepper motor.

[0122] 11. The valve assembly according to any one of embodiments 1 to 10, wherein when the actuator is supplied with a current below a threshold, the pilot pressure is controlled by a fail-safe mechanical spring valve (33).

[0123] 12. The valve assembly according to any one of Embodiments 1 to 11, wherein the main valve body moves away from the pilot chamber when the initial pressure increases, and the stroke length is about 0.05-0.5 mm, preferably about 0.1 mm.

[0124] 13. The valve assembly according to any one of embodiments 4 to 6 further includes a calibration pad (6) for calibrating the maximum load of the first spring device 44.

[0125] 14. A shock absorber (100) comprising at least one valve assembly (1a; 1b) according to any one of the foregoing embodiments.

[0126] 15. A method for controlling the flow of damping medium between damping chambers of a shock absorber via a valve assembly, the valve assembly comprising: a valve housing (2) including a first (7) and a second port (8); a pilot chamber (3) in fluid communication with the first port and / or the second port, wherein a pilot pressure (PP) is determined by hydraulic pressure in the pilot chamber; and a main valve member (4) axially movably disposed in the valve housing and arranged to interact with a main valve seat (9) of the valve housing to restrict the main fluid flow (21) between the first port (7) and the second port (8) in response to the pilot pressure acting on the main valve member, the method comprising the following steps - Elastically load the valve component in a steady-state position (4). - During the initial pressure increase of the main body, the main valve component (4) is moved away from the pilot chamber (3) to increase the volume of the pilot chamber.

[0127] 16. The method according to Example 15 further includes the following subsequent steps. - Move the main valve component toward the pilot chamber (3) so that when the pressure of the main fluid flow exceeds a predetermined value higher than the initial pressure increase, the volume of the pilot chamber is subsequently reduced.

Claims

1. A valve assembly (1) for a shock absorber, the valve assembly comprising: - Valve housing (2), the valve housing includes a first port (7) and a second port (8); - Pilot chamber (3), the pilot chamber being in fluid communication with the first port and / or the second port, wherein the pilot pressure (PP) is determined by hydraulic pressure in the pilot chamber; - A main valve component (4), which moves axially along the longitudinal axis (A) in the valve housing and is arranged to interact with the main valve seat (9) of the valve housing to restrict the main fluid flow (21) between the first port (7) and the second port (8) in response to the pilot pressure acting on the main valve component. in - The main valve component (4) is elastically loaded in a steady-state position, and is movable from the steady-state position in two directions along the longitudinal axis (A), and configured to move away from the pilot chamber (3) during the initial pressure increase of the main fluid flow, thereby increasing the volume of the pilot chamber. The valve assembly further includes: - An axially movable valve seat member (10) is arranged axially between the main valve member (4) and the main valve seat (9), wherein the axially movable valve seat member (10) includes a first limiter (R1) and a second limiter (R2) arranged in series therewith, wherein the first orifice (OR1) of the first limiter and the second orifice (OR2) of the second limiter (R2) are controlled by the axial position of the main valve member (4) relative to the valve housing (2).

2. The valve assembly according to claim 1, wherein the first limiter (R1) is arranged upstream of the main fluid flow during the compression stroke relative to the second limiter (R2).

3. The valve assembly according to any one of the preceding claims, wherein during the main fluid flow in the compression stroke, the first orifice (OR1) of the first limiter (R1) is always smaller than the second orifice (OR2) of the second limiter (R2).

4. The valve assembly according to any one of the preceding claims, wherein the first limiter (R1) is at least a partially circumferential orifice between the movable valve seat member (10) and the main valve seat (9).

5. The valve assembly according to any one of the preceding claims, wherein the second limiter (R2) is radially arranged in at least a partially circumferential orifice outside the first limiter (R1) between the movable valve seat member (10) and the main valve seat (9).

6. The valve assembly according to any one of the preceding claims, wherein the first limiter (R1) is radially spaced from the second limiter (R2) through a circumferential hole (11) in the movable valve seat member (10).

7. The valve assembly according to claim 6, wherein the main valve seat (9) includes a circumferential hole (12) aligned with a circumferential hole (11) in the movable valve seat member (10).

8. The valve assembly according to any one of the preceding claims further includes at least one gasket (13) disposed in the initial flow path (14) between the main valve member and the movable valve member.

9. The valve assembly of claim 8, wherein the at least one gasket is configured to deflect in response to an increase in pressure in the main fluid flow to allow initial fluid flow between the first port and the second port.

10. The valve assembly according to any one of the preceding claims, wherein the main valve component (4) is configured to move toward the pilot chamber (3) to reduce the volume of the pilot chamber when the pressure of the main fluid flow exceeds a predetermined value higher than the initial pressure increment.

11. The valve assembly of claim 10, wherein both the initial pressure increment and the predetermined value are generated during an increase in the main fluid flow pressure from the first port (7).

12. The valve assembly according to any one of the preceding claims, wherein the main valve member (4) is elastically loaded by a first spring device (44) located on a first side of the main valve member and a second spring device (43) located on a second side of the main valve member opposite to the first side.

13. The valve assembly according to any one of claims 1 to 12, further comprising a third limiter (R1') arranged in series with the second limiter (R2), wherein the third limiter (R1') has a constant orifice (OR1') independent of the axial position of the main valve member (4) relative to the valve housing (3).

14. A shock absorber (100) comprising at least one valve assembly (1a; 1b) according to any one of the preceding claims.

15. A method for controlling the flow of damping medium between the damping chambers of a shock absorber via a valve assembly, the valve assembly comprising: Valve housing (2), the valve housing including a first port (7) and a second port (8); pilot chamber (3), the pilot chamber being in fluid communication with the first port and / or the second port, wherein the pilot pressure (PP) is limited by hydraulic pressure in the pilot chamber; The method includes the following steps: and a main valve component (4), which is axially movably arranged in the valve housing and configured to interact with the main valve seat (9) of the valve housing to restrict the main fluid flow (21) between the first port (7) and the second port (8) in response to the pilot pressure acting on the main valve component. - Elastically load (S1) the valve component (4) in a steady-state position. - During the initial pressure increase of the main fluid flow, the main valve component (4) is moved away from the pilot chamber (3) (S2) to increase the volume of the pilot chamber. - When the pressure of the main fluid flow exceeds a predetermined value higher than the initial pressure increment, the main valve component (S3) is moved toward the pilot chamber (3) to subsequently reduce the volume of the pilot chamber, and In active flow control mode - By controlling the axial position of the main valve member (4) relative to the valve housing (2) to control the first orifice (OR1) of the first limiter (R1) and the second orifice (OR2) of the second limiter (R2), the main fluid flow is restricted (S4) at the first limiter and the second limiter arranged in series therewith.

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