Damper assembly

Abstract

The present invention relates to a damper assembly. A damper assembly for a suspension system of an associated vehicle. The damper assembly includes a cylindrical tube that extends along an axis and defines a chamber. A piston is located in the chamber and is movable along the axis in a compression direction and a rebound direction. The piston includes a piston rod that extends from a first end to a piston head. A rebound stopper is located on the piston rod, between the first end and the piston head. A hydraulic rebound stop ("HRS") piston is located in an HRS chamber. A rebound spring biases the HRS piston toward an adapter plate in the HRS chamber. The piston rod is slidably received within the HRS piston in the rebound direction until the rebound stopper contacts the HRS piston and compresses the rebound spring.

Description

Technical Field

[0001] The present invention generally relates to a damper assembly for a suspension system. Background Art

[0002] Vehicles such as automobiles typically have a suspension system that includes absorber units mounted between the vehicle's wheels and the body or substructure. The suspension is typically configured based on vehicle integration to keep the wheels in contact with the driving surface by absorbing the energy of forces on the vehicle's wheels or other parts. As technology has evolved, various types of absorber units have been developed. A particularly popular type of absorber unit is a hydraulic cylinder configured to utilize telescopic compression to absorb forces. After compression, the hydraulic cylinder "rebounds", causing the hydraulic cylinder to expand so that the hydraulic cylinder can be compressed again.

[0003] Hydraulic cylinders typically include a hydraulic rebound stop ("HRS") feature to increase the damping force when the hydraulic cylinder extends to near full rebound position. One prior art HRS feature includes an additional piston located on the piston rod at a distance from the main piston. In operation, the additional piston travels into an auxiliary cylinder where a tapered groove is located at the top of the hydraulic cylinder. When the additional piston travels into the auxiliary cylinder during rebound, the tapered groove creates an increased hydraulic restriction to reduce the impact at the end of the stroke. Another prior art HRS feature includes a main piston that engages a piston ring to form an HRS chamber. The piston ring seals the flow at the main piston during rebound and forces fluid through an annular flow path around the main piston and into the HRS valve to create an increased damping force. A spring positions the piston ring and compresses as the main piston travels towards full rebound. While these prior art HRS features reduce the impact harshness at full hydraulic cylinder extension, the impact harshness is not completely eliminated, and problems such as mechanical wear and tear and unpleasant interruptions to the ride experience persist.

[0004] Accordingly, there has been a continuing desire to improve the operating framework and efficiency of the rebound stop feature in suspension systems to provide a longer service life and further reduce unpleasant and harsh rebound movements. Summary of the Invention

[0005] The features and technical advantages of the present invention have been outlined rather broadly above so that the detailed description of the present invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the present invention. Those skilled in the art will appreciate that the concepts and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. Those skilled in the art should also recognize that such equivalent embodiments do not depart from the spirit and scope of the present invention as set forth in the appended claims. This section provides a general overview of the present disclosure and should not be construed as an exhaustive and comprehensive listing of all objects, aspects, features, and advantages associated with the present disclosure.

[0006] The present invention provides a damper assembly having a hydraulic rebound stop (“HRS”) feature that provides a longer service life and further reduces unpleasant and violent rebound movement.

[0007] One aspect of the present invention is to provide a damper assembly for a suspension system of an associated vehicle. The damper assembly includes a tubular tube extending along an axis and defining a chamber. A piston is located in the chamber and is movable along the axis in a compression direction and a rebound direction. The piston includes a piston rod extending from a first end to a piston head. A rebound stopper is located on the piston rod between the first end and the piston head. A hydraulic rebound stop (“HRS”) piston includes a sleeve portion extending to an HRS piston head. A rebound spring urges the HRS piston in a direction from the first end of the piston toward the rebound stopper. The piston rod is slidable within the HRS piston in the rebound direction until the rebound stopper contacts the HRS piston and compresses the rebound spring.

[0008] Another aspect of the present invention provides a damper assembly for a suspension system of an associated vehicle. The damper assembly includes a tubular tube extending along an axis and defining a chamber. A piston is located in the chamber and is movable along the axis in a compression direction and a rebound direction. The piston includes a piston rod extending from a first end to a piston head. A rebound stopper is located on the piston rod between the first end and the piston head. A hydraulic rebound stop (“HRS”) chamber and an adapter plate separating the HRS chamber from the chamber of the tubular tube. The HRS piston is located in the HRS chamber. A rebound spring urges the HRS piston toward the adapter plate. The adapter plate defines an opening for receiving the rebound stopper to contact the HRS piston and compress the rebound spring.

[0009] Another aspect of the present invention is to provide a damper assembly for a suspension system of an associated vehicle. The damper assembly includes a cylindrical tube that extends along an axis and defines a chamber. A piston is located within the chamber and is movable along the axis in a compression direction and a rebound direction. The piston includes a piston rod that extends from a first end to a piston head. A rebound stopper is located on the piston rod, between the first end and the piston head. An inner rebound cylinder defines a hydraulic rebound stop ("HRS") chamber. The inner rebound cylinder is connected to the cylindrical tube by an adapter plate that separates the HRS chamber from the chamber of the cylindrical tube. An HRS piston is located within the HRS chamber. A rebound spring is also located within the HRS chamber, and the rebound spring urges the HRS piston toward the adapter plate. The adapter plate defines an opening for receiving the rebound stopper to contact the HRS piston and compress the rebound spring.

[0010] Based on the description provided herein, other application areas will become apparent. The description and specific examples in the present disclosure are for illustrative purposes only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Other advantages of the present invention will be readily understood, as the other advantages of the present invention become better understood by reference to the detailed description considered in conjunction with the following drawings, wherein:

[0012] Figure 1 is a cross-sectional side view of a damper assembly for a suspension system of a vehicle according to the principles of the present disclosure;

[0013] Figure 2 is a cross-sectional side view of a damper assembly including a rebound assembly in a first rebound stage;

[0014] Figure 3 is a cross-sectional side view of the damper assembly when the rebound assembly is in a second rebound stage; and

[0015] Figure 4 is a cross-sectional side view of the damper assembly when the rebound assembly further enters the second rebound stage. DETAILED DESCRIPTION

[0016] Example embodiments will now be described more fully with reference to the accompanying drawings. Generally, the described embodiments relate to a solenoid assembly for a suspension system of a vehicle. However, the example embodiments are provided only so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that the example embodiments may be implemented in many different forms and should not be construed as limiting the scope of the present disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known techniques have not been described in detail.

[0017] Referring to the accompanying drawings, in which like reference numerals refer to corresponding parts throughout several views, there is provided a damper assembly for a suspension system of a vehicle. The damper assembly improves the operating framework and efficiency of the hydraulic rebound stop (“HRS”) feature in the suspension system to provide a longer service life and further reduce unpleasant and violent rebound movements. In some embodiments, the damper assembly is configured as a twin-tube damper.

[0018] First referring to Figures 1 to 4 , the damper assembly 20 has an outer storage tube 24 extending between a first end 26 and a second end 28 along an axis A. The damper assembly 20 includes a cylinder tube assembly 30 located within the outer storage tube 24 and extending along the axis A. The cylinder tube assembly 30 includes a cylindrical tube 32 and a piston and rod assembly 34 located within the cylindrical tube 32 and a bottom valve assembly 31 at the second end 28 of the cylindrical tube 32. The piston and rod assembly 34 includes a piston rod 36 extending into a piston head 38, the piston head 38 being sized to be similar to the inner diameter of the cylindrical tube 32. The piston head 38 travels from the first end 26 towards the second end 28 during compression (i.e., in the compression direction) and from the second end 28 towards the first end 26 during rebound (i.e., in the rebound direction).

[0019] The damper assembly 20 further includes a cap seal assembly 50 located on the first end 26. The first end 26 may include a radially inwardly extending flange 42, which may be roll-formed. The seal cap assembly 50 is located within the outer storage tube 24 and is sealed against the outer storage tube 24 with an annular seal 52 and against the piston rod 36 with a rod seal 53. The seal cap assembly 50 includes an annular step 54 that defines a first circumferential surface 56 and a second circumferential surface 58, the second circumferential surface 58 extending radially inwardly and axially towards the second end 28 from the first circumferential surface 56.

[0020] The damper assembly 20 includes a hydraulic rebound assembly 60 positioned against the seal cap assembly 50 and axially extending toward the second end 28. The hydraulic rebound assembly 60 includes an outer rebound cylinder 62 and an inner rebound cylinder 64 located within the outer rebound cylinder 62. The outer rebound cylinder 62 abuts against the first circumferential surface 56 of the seal cap assembly 50, and the inner rebound cylinder 64 abuts against the second circumferential surface 58 of the seal cap assembly 50. The inner diameter of the outer rebound cylinder 62 is equal to or slightly larger than the annular step 54 of the seal cap assembly 50 to fit around the annular step 54 in a hugging engagement. The inner rebound cylinder 64 may include one or more tapered grooves axially extending on the inner surface for additional control of fluid flow from the hydraulic rebound assembly 60.

[0021] The rebound adapter plate 66 defines an annular shape and connects the outer rebound cylinder 62 and the inner rebound cylinder 64 to the tubular tube 32. More specifically, the rebound adapter plate 66 includes a first side 68 defining an annular depression for positioning both the outer rebound cylinder 62 and the inner rebound cylinder 64 and a second side 70 defining an annular depression for positioning the tubular tube 32. The rebound adapter plate 66 extends radially inwardly toward the axis A and defines an opening 67 for receiving the piston rod 36 and a rebound stop 72 located on the piston rod 36. The rebound stop 72 is located on the piston rod 36 between the piston head 38 and the first end 26. Thus, the tubular tube 32 defines a main chamber 74, and the inner rebound cylinder 64 defines a hydraulic rebound stop (“HRS”) chamber 76. A rebound spring 78 is located within the HRS chamber 76 and extends from the seal cap assembly 50 to the HRS piston 80. The rebound spring 78 presses the HRS piston 80 toward the adapter plate 66. The spring stiffness of the rebound spring 78 can be adjusted to provide various levels of force for rebound control as needed.

[0022] The HRS piston 80 includes a sleeve portion 82 defining a passage 83 for receiving the piston rod 36 such that the sleeve portion 82 is slidable onto the piston rod 36. The HRS piston 80 also includes an HRS piston head 84 that extends radially outwardly and is larger than the opening 67 in the rebound adapter plate 66 such that the HRS piston head 84 remains within the HRS chamber 76. In some embodiments, the HRS piston head 84 includes an HRS piston outer diameter that is slightly smaller than the inner diameter of the inner rebound cylinder 64 to allow fluid to flow between the HRS piston head 84 and the inner diameter of the inner rebound cylinder 64. In some embodiments, the HRS piston head 84 includes one or more holes axially extending therethrough to allow fluid flow. In some embodiments, the piston head 38 defines a main outer diameter that is larger than the HRS piston outer diameter.

[0023] Now specifically referring to Figure 1, the damper assembly 20 is shown in a compressed or partially compressed state. The compressed state typically occurs when a wheel (not shown) connected to the damper assembly 20 receives some force, for example, when the associated vehicle travels around a bend or on a bumpy driving surface. As the piston head 38 travels along the axis A towards the second end 28 within the cylindrical tube 32, the force is dissipated. Once compressed, the pressure accumulated in the main chamber 74 forces the piston head 38 to return towards the first end 28 within the cylindrical tube 32 during rebound. Since the damper assembly 20 is under a constant weight, rebound may occur in the case of weight reduction. For example, when the associated vehicle travels over a pothole, the sudden reduction in weight causes the piston head 38 to travel towards the first end 28 within the cylindrical tube 32.

[0024] Now refer to Figure 2 , the damper assembly 20 is shown in a first rebound stage. In the first rebound stage, the pressure accumulated in the main chamber 74 forces the piston head 38 to return towards the first end 26 within the cylindrical tube 32. The piston rod 36 travels within the opening 67 in the rebound adapter plate 66, the passage 83 in the sleeve portion 82 of the HRS piston 80, and the hole 48 within the seal portion 47. Figure 3 is a cross-sectional side view of the damper assembly 20 when the hydraulic rebound assembly 60 is in a second rebound stage. In the second rebound stage, the rebound stopper 72 enters the opening 67 in the rebound adapter plate 66 and contacts the HRS piston 80, thereby increasing the force required for further rebound travel via the spring load of the rebound spring 78 and the fluid transmission around the piston head 84 within the HRS chamber 76. Figure 4 is a cross-sectional side view of the damper assembly 20 when the hydraulic rebound assembly 60 further enters the second rebound stage. As illustrated, the rebound stopper 72 further pushes the HRS piston 80 into the HRS chamber 76.

[0025] It should be understood that the foregoing description of the embodiments has been provided for purposes of illustration. In other words, the described disclosure is not intended to be exhaustive or to limit the disclosure. In other words, the various elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The various elements or features of a particular embodiment may also vary in many respects. Such variations should not be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

1. A damper assembly for a suspension system of an associated vehicle, the damper assembly comprising: A cylindrical tube that extends along an axis and defines a chamber; A piston that is located within the chamber and is movable along the axis in a compression direction and a rebound direction; The piston includes a piston rod that extends from a first end to a piston head; A rebound stopper that is located on the piston rod between the first end and the piston head; A hydraulic rebound stopper piston that includes a sleeve portion that extends to a hydraulic rebound stopper piston head; A rebound spring that urges the hydraulic rebound stopper piston from the direction of the first end of the piston toward the rebound stopper; and Wherein the piston rod is slidable within the hydraulic rebound stopper piston in the rebound direction until the rebound stopper contacts the hydraulic rebound stopper piston and compresses the rebound spring, Wherein the hydraulic rebound stopper piston is located within a hydraulic rebound stopper chamber defined by an inner rebound cylinder, Wherein an adapter plate separates the chamber of the cylindrical tube from the hydraulic rebound stopper chamber, Wherein the adapter plate includes a first side that defines an annular recess for positioning an end of the inner rebound cylinder, and wherein the adapter plate further includes a second side that defines an annular recess for positioning an end of the cylindrical tube.

2. The damper assembly according to claim 1, wherein, The adapter plate defines an opening, and wherein the rebound stopper is sized to pass through the opening, and the hydraulic rebound stopper piston head is sized to be larger than the opening.

3. The damper assembly according to claim 2, wherein, The hydraulic rebound stopper piston head is sized to be smaller than an inner surface of the inner rebound cylinder to allow fluid to flow around the hydraulic rebound stopper piston head.

4. The damper assembly according to claim 2, wherein, The rebound spring urges the hydraulic rebound stopper piston into abutment with the adapter plate.

5. The damper assembly according to claim 1, wherein, The rebound spring extends around the sleeve portion of the hydraulic rebound stopper piston.

6. The damper assembly according to claim 1, wherein, The hydraulic rebound stopper piston head defines a hydraulic rebound stopper piston outer diameter, and the piston head defines a major outer diameter that is larger than the hydraulic rebound stopper piston outer diameter.

7. A damper assembly for a suspension system of an associated vehicle, the damper assembly comprising: A cylindrical tube that extends along an axis and defines a chamber; A piston that is located within the chamber and is movable along the axis in a compression direction and a rebound direction; The piston includes a piston rod that extends from a first end to a piston head; A rebound stopper that is located on the piston rod between the first end and the piston head; A hydraulic rebound stopper chamber and an adapter plate that separates the hydraulic rebound stopper chamber from the chamber of the cylindrical tube; A hydraulic rebound stopper piston that is located within the hydraulic rebound stopper chamber; A rebound spring that biases the hydraulic rebound stopper piston toward the adapter plate; And Wherein the adapter plate defines an opening for receiving the rebound stopper to contact the hydraulic rebound stopper piston and compress the rebound spring, Wherein, the hydraulic rebound stop chamber is defined by an inner rebound cylinder, and wherein the inner rebound cylinder is connected to one end of the tubular pipe through the adapter plate, Wherein, the adapter plate includes a first side defining an annular recess for positioning the end of the inner rebound cylinder, and wherein the adapter plate further includes a second side defining an annular recess for positioning the end of the tubular pipe.

8. The damper assembly according to claim 7, wherein, The hydraulic rebound stop piston is sized to be larger than the opening in the adapter plate.

9. The damper assembly according to claim 8, wherein, The rebound spring urges the hydraulic rebound stop piston into abutment with the adapter plate.

10. The damper assembly according to claim 7, wherein, The hydraulic rebound stop piston includes a sleeve portion and a hydraulic rebound stop piston head.

11. The damper assembly according to claim 10, wherein, The piston rod is slidably received within the hydraulic rebound stop piston.

12. The damper assembly according to claim 10, wherein, The rebound spring extends around the sleeve portion of the hydraulic rebound stop piston.

13. The damper assembly according to claim 10, wherein, The hydraulic rebound stop piston head defines a hydraulic rebound stop piston outer diameter, and the piston head defines a major outer diameter larger than the hydraulic rebound stop piston outer diameter.

14. A damper assembly for a suspension system of an associated vehicle, the damper assembly comprising: A tubular pipe extending along an axis and defining a chamber; A piston located within the chamber and movable along the axis in a compression direction and a rebound direction; The piston includes a piston rod extending from a first end to a piston head; A rebound stopper located on the piston rod between the first end and the piston head; An inner rebound cylinder defining a hydraulic rebound stop chamber, the inner rebound cylinder being connected to the tubular pipe through an adapter plate that separates the hydraulic rebound stop chamber from the chamber of the tubular pipe; A hydraulic rebound stop piston located within the hydraulic rebound stop chamber; A rebound spring within the hydraulic rebound stop chamber, the rebound spring urging the hydraulic rebound stop piston toward the adapter plate; and Wherein, the adapter plate defines an opening for receiving the rebound stopper to contact the hydraulic rebound stop piston and compress the rebound spring, Wherein, the adapter plate includes a first side defining an annular recess for positioning the end of the inner rebound cylinder, and wherein the adapter plate further includes a second side defining an annular recess for positioning the end of the tubular pipe.

15. The damper assembly according to claim 14, wherein, The hydraulic rebound stop piston includes a sleeve portion and a hydraulic rebound stop piston head, and wherein the piston rod is slidable within the hydraulic rebound stop piston.

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