Balanced continuous semi-active damper

Abstract

This application discloses a continuously variable damper. The damper includes an elongated outer tube and an inner tube, with a piston inside the inner tube. The piston defines a springback chamber and a compression chamber. An active springback valve is fluidly connected to the springback chamber via a lower springback tube, and an active compression valve is fluidly connected to the compression chamber via a lower compression tube. An intake compression valve is fluidly connected to the springback chamber via a lower springback tube, and an intake springback valve is fluidly connected to the compression chamber via a lower compression tube. The opposite positions of the intake valves balance the active springback valve and the compression valve to avoid asymmetrical / bending loads on the inner tube of the damper.

Description

[0001] Cross-references to related applications

[0002] This patent application claims priority and all benefits to U.S. Patent Application No. 16 / 678,294, filed November 8, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to dampers. More specifically, this disclosure relates to a damper having an external active control valve balanced by a passive intake valve. Background Technology

[0004] Dampers used in vehicles are typically found in a wide variety of vehicle components. Some vehicles include semi-active damping, which adjusts the damping level according to road conditions and vehicle dynamics. The shock absorber is located between the body and the vehicle's suspension system. A piston is located within the damper. The piston is connected to the body or vehicle suspension via a piston rod. When the damper compresses or extends, fluid flows between the rebound and compression chambers within the damper to counteract vibrations. Greater or lower damping forces can be generated by adjusting the flow of damping fluid between the chambers.

[0005] An improved damper is needed. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of a vehicle incorporating a suspension system according to an example of this disclosure.

[0007] Figure 2 This is a plan view of a variable damper according to an example of this disclosure.

[0008] Figure 3 The plan view of the variable damper according to the example of this disclosure shows the springback flow path.

[0009] Figure 4 The diagram shows a compressed flow path from a plan view of a variable damper according to an example of this disclosure. Detailed Implementation

[0010] This disclosure relates to a damping system that continuously adjusts the damping level according to road conditions and vehicle dynamics. (Reference) Figure 1 The diagram shows a vehicle 10 with a suspension system 12 and a body 14. The suspension system 12 includes dampers 20 and coil springs 22. The dampers 20 are semi-active, and their damping levels are controlled by an electronic control unit (ECU) 24. The ECU 24 receives information (acceleration, displacement, steering, braking, speed) from sensors (not shown) at different locations on the vehicle to independently adjust each damper.

[0011] refer to Figure 2This exemplary disclosure provides a continuously variable damper 20, comprising an elongated outer tube 26 having a first end 27A and a second end 27B. The outer tube 26 has an inner tube 28 concentrically contained therein. A rod 32, including a piston 30 at a first rod end 31, is contained within the inner tube 28, and the rod 32 includes a second rod end 34 extending outside the elongated outer tube 26 via a rod guide assembly 36. As shown, the piston 30 and the inner tube 28 define a springback chamber 38 and a compression chamber 40. The springback chamber 38 and the compression chamber 40 contain fluid, preferably hydraulic oil suitable for use with a damper.

[0012] The damper 20 includes an active springback valve 54 in fluid communication with the springback chamber 38 via a springback lower tube 60. The active springback valve 54 has variable flow resistance. The damper 20 also includes an active compression valve 64 in fluid communication with the compression chamber 40 via a compression lower tube 70. The active compression valve 64 has variable flow resistance. An intake compression valve 80 is provided in fluid communication with the springback chamber 38 via the springback lower tube 60, such that fluid flows through the active compression valve 64 and the intake compression valve 80 when the second rod end 34 moves toward the rod guide 36 (i.e., during the compression stroke). The damper 20 also includes an intake springback valve 74 in fluid communication with the compression chamber 40 via the compression lower tube 70, wherein fluid flows through the active springback valve 54 and the intake springback valve 74 when the second rod end 34 moves away from the rod guide 36.

[0013] As shown in the figure, the active springback valve 54 and the active compression valve 64 are oriented perpendicular to the long axis of the elongated outer tube 26. During the compression stroke, as the second rod end 34 moves toward the rod guide 36, fluid flows through the active compression valve 64 located on one side of the elongated outer tube 26 and the intake compression valve 80 located on the opposite side of the elongated outer tube 26, thereby substantially balancing the bending moment on the elongated outer tube 26. Similarly, during the springback stroke, as the second rod end 34 moves away from the rod guide 36, fluid flows through the active springback valve 54 located on one side of the elongated outer tube 26 and the intake springback valve 74 located on the opposite side of the elongated outer tube 26, thereby substantially balancing the bending moment on the elongated outer tube 26. The relative positions of the intake valves balance the active springback valve and the compression valve, which prevents asymmetrical loads, i.e., bending, on the inner tube 28 in the damper 20. The reduction in bending moment allows for a relatively smaller continuous semi-active damper for any given load compared to a continuous semi-active damper that does not include an intake rebound valve and an intake compression valve, because the wall thickness of the outer and inner tubes does not need to be thick enough to resist compressive loads and bending moments. The ability to provide smaller dampers can be particularly useful for use with electric vehicles or for addressing space and packaging challenges.

[0014] As shown in the disclosed examples, the active springback valve 54 has an active springback valve inlet passage 58 defining an active springback contact area, and the intake springback valve 74 includes an intake springback valve outlet passage 78 defining an intake springback contact area. The term contact area describes the two-dimensional area of ​​the outlet. As shown, the contact areas are substantially the same to further reduce bending moments. Similarly, the active compression valve 64 includes an active compression valve inlet passage 68 defining a compression contact area, and the intake compression valve 80 includes an intake compression valve outlet passage 84 defining a contact area that can be substantially the same as the contact area of ​​the active compression valve inlet passage 68. As shown, the active springback valve 54 can be offset approximately 180 degrees from the intake springback valve 74, and the active compression valve 64 can be offset approximately 180 degrees from the intake compression valve 80 to further balance fluid flow and substantially eliminate bending moments.

[0015] refer to Figure 2 The damper 20 includes an elongated outer tube 26. An inner tube 28 is concentrically positioned within the outer tube 26. The inner tube 28 is fixed at one end to a rod guide 36 assembly and at the other end to a cylinder end 44. As shown, the length of the outer tube 26 is greater than the length of the inner tube 28. The outer tube 26 extends beyond the inner tube 28 and includes a damper end 50. A floating piston 48 is located between the damper end 50 and the cylinder end 44 to define an exhaust chamber 52 and a low-pressure chamber 42. The exhaust chamber 52 is filled with a suitable gas, such as nitrogen. The low-pressure chamber 42 extends into the space between the outer tube 26 and the inner tube 28. The floating piston 48 moves during operation, causing the gas in the exhaust chamber 52 to be compressed, thereby maintaining a suitable volume for the fluid in the damper. The low-pressure chamber 42 contains a fluid, such as oil, which is typically hydraulic oil. The low-pressure chamber 42 extends between the inner tube 28 and the outer tube 26 through a passage 46 in the cylinder end 44. In one example, cylinder end 44 includes at least two channels 46.

[0016] Rod 32 is housed within inner tube 28. Rod 32 extends from the outside of damper 20 through rod guide assembly 36 such that second rod end 34 is outside damper 20. Piston 30 is connected to first rod end 31 within inner tube 28. Piston 30 defines springback chamber 38 and compression chamber 40. Springback chamber 38 and compression chamber 40 are filled with the same oil as low-pressure chamber 42, and the manner of fluid flow between low-pressure chamber 42, springback chamber 38, and compression chamber 40 is described in more detail below.

[0017] Damper 20 is variable, meaning the damping level can be adjusted based on conditions. Variable damping is provided using an active rebound valve 54 and an active compression valve 64. Both active rebound valve 54 and active compression valve 64 are one-way valves. Active rebound valve 54 includes a rebound solenoid 56, which is a controllable valve operably connected to ECU 24. Similarly, active compression valve 64 includes a solenoid valve 66 operably connected to ECU 24. Solenoid valves 56 and 66 can be electro-hydraulic valves. ECU 24 receives information (acceleration, displacement, steering, braking, speed) from sensors (not shown) at different locations on the vehicle to independently adjust each damper, thereby changing the damping rate to adapt to road conditions. For example, the ECU can restrict fluid flow through damper 20 using solenoid valves 56 and 66 to provide a stiffer ride, or provide less restriction to provide a softer ride.

[0018] The active rebound valve 54 is in fluid communication with the rebound chamber 38 via the active rebound valve inlet passage 58 and with the low-pressure chamber 42 via the active rebound valve outlet passage 59. The active rebound valve inlet passage 58 is supplied via the rebound lower tube 60 and the rebound inner tube passage 62. The rebound lower tube 60 is a sealed tube that defines a flow path from the rebound chamber 38 through the rebound inner tube passage 62 into the active rebound valve inlet passage 58. The active rebound valve inlet passage 58 defines a contact area representing the two-dimensional area of ​​the passage 58. The rebound lower tube 60 is located between the outer tube 26 and the inner tube 28 and extends to allow fluid flow through the active rebound valve 54 and the rebound chamber 38.

[0019] The active compression valve 64 is in fluid communication with the compression chamber 40 via the active compression valve inlet passage 68 and with the low-pressure chamber 42 via the active compression valve outlet passage 69. The active compression valve inlet passage 68 is supplied through the compression lower tube 70 and the compression inner tube passage 72. The active compression valve inlet passage 68 defines a contact area representing the two-dimensional area of ​​the passage 68. The compression lower tube 70 is also located between the outer tube 26 and the inner tube 28. The compression lower tube 70 is a sealed tube that defines a flow path from the compression chamber 40 through the compression inner tube passage 72 into the active compression valve 64, and further defines a fluid passage from the intake rebound valve outlet passage 78 circumferentially around the inner tube 28 and through the compression inner tube passage 72 into the compression chamber 40.

[0020] As shown in the figure, the damper 20 also includes an intake spring valve 74, which is a passive one-way valve. The intake spring valve 74 includes a biasing element such as a spring 76 and associated intake spring valve inlet passage 77 and intake spring valve outlet passage 78. The intake spring valve inlet passage 77 receives fluid from the low-pressure chamber 42, and the intake spring valve outlet passage 78 outputs fluid to the compression chamber 40 by circumferentially guiding the fluid through the lower compression pipe 70 to the inner compression pipe passage 72.

[0021] The damper 20 also includes an intake compression valve 80, which is a passive one-way valve. The intake compression valve 80 includes a biasing element such as a spring 82 and associated intake compression valve outlet passage 84 and intake compression valve inlet passage 83. The intake compression valve inlet passage 83 receives fluid from the low-pressure chamber 42 and outputs the fluid to the rebound chamber 38 via the compression valve outlet passage through the rebound lower tube 60 and the rebound inner tube passage 62.

[0022] refer to Figure 3 The diagram illustrates the flow path for the rebound cycle. In the rebound cycle, rod 32 and piston 30 extend away from damper 20 as shown by arrow 86. Fluid is forced from the rebound chamber 38 through the rebound inner tube passage 62 and the rebound lower tube 60 into the active rebound valve inlet passage 58, as shown by arrows 88 and 90. The fluid then flows through the active rebound valve 54. The resistance to the fluid flowing through the active rebound valve 54 is controlled by ECU 24. The fluid, as shown by arrow 92, flows through the active rebound valve 54 and out through the active rebound valve outlet passage 59 into the low-pressure chamber 42. As rod 32 and piston 30 move away from the damper as shown by arrow 86, floating piston 48 moves in the same direction as shown by arrow 94. As floating piston 48 moves in the direction of arrow 94, fluid flows from the low-pressure chamber 42 through passage 46 and into the intake rebound valve inlet passage 77. The fluid then flows through the intake rebound valve 74 as indicated by arrows 96 and 98 and enters the compression chamber 40 via the intake rebound valve outlet passage 78, through the compression lower pipe 70, and out of the compression inner pipe passage 72.

[0023] As shown in the figure, the rebound valve outlet passage 78 has a contact area substantially the same as the active rebound valve inlet passage 58. The intake rebound valve 74 is approximately 180 degrees offset from the active rebound valve 54 to balance the force of fluid flowing perpendicular to the direction of arrow 86, thereby substantially eliminating the bending moment on the damper 20. As described above, fluid flows between the rebound chamber 38 and the compression chamber 40 to provide damping.

[0024] refer to Figure 4The diagram illustrates the flow path for the compression cycle. In the compression cycle, rod 32 and piston 30 extend toward damper 20 as shown by arrow 98. Fluid is forced from the compression chamber 40 through the compression inner tube passage 72 and through the compression lower tube 70 into the active compression valve inlet passage 68, as shown by arrow 100. The fluid then flows through the active compression valve 64. The resistance to the fluid flowing through the active compression valve 64 is controlled by ECU 24. The fluid, as shown by arrow 102, flows through the active compression valve 64 and out through the active compression valve outlet passage 69 into the low-pressure chamber 42. As shown, fluid from the active compression valve 64 passes through passage 46, causing the floating piston to move in the direction shown by arrow 104. As rod 32 and piston 30 move toward damper 20 as shown by arrow 98, fluid is forced into the active compression valve 64, which is also forced into the inlet passage of the intake valve 80, i.e., intake compression valve inlet passage 83, as shown by arrow 106. As indicated by arrow 108, the fluid is forced through the intake compression valve 80 and through the lower rebound pipe 60, through the inner rebound pipe channel 62 and into the rebound chamber 38.

[0025] As shown in the figure, the intake compression valve outlet channel 84 has a contact area that is basically the same as that of the active compression valve inlet channel 68. The intake valve 80 is offset by approximately 180 degrees from the active compression valve 64 to balance the force of fluid flowing in the direction perpendicular to arrow 94, thereby essentially eliminating the bending moment on the damper 20.

[0026] By providing a combination of active and passive valves, fluid flows through the damper in an improved force-balanced manner. By balancing the fluid forces associated with the active spring valve and the active compression valve using passive spring and compression intake valves, this disclosure enables semi-active damping systems with orthogonal active valves to have a reduced size, thereby allowing for a wider range of potential applications for such systems.

[0027] This disclosure has been described in an illustrative manner, and it should be understood that the terminology used is intended to be descriptive rather than restrictive. In view of the foregoing teachings, many modifications and variations of this disclosure are possible, and this disclosure may be implemented in ways different from the specific description.

Claims

1. A continuously variable damper, comprising: An elongated outer tube having a first end and a second end and having an inner tube concentrically contained therein; A rod having a piston at a first rod end and a second rod end extending outside the elongated outer tube via a rod guide, the piston and the inner tube defining a spring-loaded chamber and a compression chamber, the spring-loaded chamber and the compression chamber containing fluid; An active rebound valve, which is in fluid communication with the rebound chamber via a rebound lower tube, has variable flow resistance. An active compression valve, which is in fluid communication with the compression chamber via a compression lower pipe, has variable flow resistance. An intake compression valve is fluidly connected to the rebound chamber via the rebound lower tube, wherein fluid flows through the active compression valve and the intake compression valve when the second rod end moves toward the rod guide; and An intake rebound valve, which is in fluid communication with the compression chamber via the lower compression pipe, allows fluid to flow through both the active rebound valve and the intake rebound valve as the second rod end moves away from the rod guide. Specifically, the intake rebound valve is radially shifted approximately 180 degrees from the active rebound valve. and / or The intake compression valve is radially shifted approximately 180 degrees from the active compression valve.

2. The continuously variable damper according to claim 1, wherein, Each active rebound valve has an active rebound contact area, and the intake rebound valve has an intake rebound contact area that is substantially the same as the active rebound contact area.

3. The continuously variable damper of claim 1 further includes a floating piston defining an air chamber near the first end of the elongated outer tube.

4. The continuously variable damper according to claim 3 further includes a cylinder end, wherein the lower compression cylinder end and the floating piston are separated to form a low-pressure chamber, the low-pressure chamber containing the fluid.

5. The continuously variable damper according to claim 4, wherein, The cylinder end includes at least two channels.

6. The continuously variable damper according to claim 5, wherein, The low-pressure chamber extends through a channel in the cylinder end into the space between the inner and outer tubes.

7. The continuously variable damper according to claim 1, wherein, Both the active rebound valve and the active compression valve include a solenoid.

8. The continuously variable damper according to claim 7, wherein, The intake compression valve and the intake rebound valve are passive.

9. A continuously variable damper, comprising: An elongated outer tube having a first end and a second end and having an inner tube concentrically contained therein, the inner tube having a first end and a second end, the first end of the inner tube terminating at a rod guide and the second end terminating at a cylinder end, such that a low-pressure chamber is defined between the cylinder end and the second end of the outer tube and between the inner tube and the outer tube. A rod having a piston at a first rod end and a second rod end extending outside the elongated outer tube via a rod guide, the piston and the inner tube defining a springback chamber between the piston and the rod guide, and the piston and the inner tube defining a compression chamber between the piston and the cylinder end; An active rebound valve, which is in fluid communication with the rebound chamber via a rebound lower tube, has variable flow resistance that can be controlled by an ECU. An active compression valve, which is in fluid communication with the compression chamber via a compression lower pipe, has variable flow resistance that can be controlled by an ECU. An intake compression valve is fluidly connected to the rebound chamber via the rebound lower tube, wherein fluid flows through the active compression valve and the intake compression valve when the second rod end moves toward the rod guide; and An intake rebound valve is in fluid communication with the compression chamber via the lower compression tube, wherein fluid flows through the active rebound valve and the intake rebound valve when the second rod end moves away from the rod guide; Wherein, the intake rebound valve is radially shifted approximately 180 degrees from the active rebound valve, and / or, the intake compression valve is radially shifted approximately 180 degrees from the active compression valve, and The fluid flow between the active compression valve and the intake compression valve essentially eliminates the bending moment on the inner tube, and the fluid flow between the active rebound valve and the intake rebound valve essentially eliminates the bending moment on the inner tube.

10. The continuously variable damper of claim 9 further includes a floating piston forming a chamber between the floating piston and the second end of the outer tube, wherein the low-pressure chamber is defined between the cylinder end and the floating piston and between the inner tube and the outer tube.

11. The continuously variable damper according to claim 10, wherein, Each of the active rebound valves has an active rebound contact area, and the intake rebound valve has an intake rebound contact area that is substantially the same as the active rebound contact area.

12. The continuously variable damper according to claim 9, wherein, Both the active rebound valve and the active compression valve include a solenoid.

13. The continuously variable damper according to claim 12, wherein, The intake compression valve and the intake rebound valve are passive.

14. The continuously variable damper according to claim 9, wherein, The active rebound valve is an electro-hydraulic valve.

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