Abstract:
Apparatus are provided for a jounce bumper system for use with a damper. The jounce bumper system includes a first mount and a jounce bumper having a first end coupled to the first mount and a second end. The jounce bumper system includes a flexible striker cap spaced apart from the second end of the jounce bumper in a first position. The flexible striker cap includes a first surface in contact with the second end in a second position and defines a cavity opposite the first surface. The jounce bumper system further includes an insert received within the cavity.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure generally relates to suspension systems for a vehicle and more particularly relates to systems and methods for a damper having an insert for use with a suspension system of a vehicle. 
       BACKGROUND 
       [0002]    Vehicles are typically equipped with suspension systems that include components that contract and expand to provide flexible relative movement between the body and chassis. During normal driving conditions, these components gradually dissipate the forces generated by bumps, potholes, and other road surface anomalies in a controlled manner that helps the driver to maintain control over the vehicle and provides passengers a comfortable driving environment. 
         [0003]    In certain instances, the vehicle may encounter a road surface anomaly that causes the components of the suspension to contract beyond the designed operating range of springs and shocks/struts, which may be referred to as jounce. Thus, many suspension systems employ impact load management systems that limit jounce. Such systems typically include jounce bumper assemblies configured to engage during severe impact events and provide a “bottoming” or a limit to further contractive motion. These assemblies may be used to limit jounce between, for example, sprung and unsprung vehicle masses and may be conveniently located within the body of a shock or strut. Such integrated assemblies typically include a rigid metallic striker plate coupled to the end cap of the damper tube and a jounce bumper coupled to the upper mount. Each is aligned along a common piston rod and spaced apart so that, during an impact event, the striker cap and jounce bumper engage causing the bumper to deform axially along the piston rod in the direction of loading. However, such a configuration provides little cushioning effect from impact loads because of the rigidity of the striker plate and the marginal capacity of the bumper to absorb associated energy. Accordingly, these and other similarly affected elements including the chassis frame and vehicle body structure are generally designed with a more rugged construction of greater mass and volume than would otherwise be required if the suspension system components were more energy absorbing. 
         [0004]    Accordingly, it is desirable to provide systems and methods for a damper having an insert for managing impact load in a vehicular suspension system that enables the use of lighter weight supporting materials without adversely impacting other desirable vehicle characteristics such as driving comfort or vehicle controllability. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. 
       SUMMARY 
       [0005]    In one embodiment, an apparatus is provided for a jounce bumper system for use with a damper. The jounce bumper system includes a first mount and a jounce bumper having a first end coupled to the first mount and a second end. The jounce bumper system includes a flexible striker cap spaced apart from the second end of the jounce bumper in a first position. The flexible striker cap includes a first surface in contact with the second end in a second position and defines a cavity opposite the first surface. The jounce bumper system further includes an insert received within the cavity. 
         [0006]    In another embodiment, a suspension system is provided for a vehicle. The suspension system includes a damper tube coupled to a first portion of the vehicle and including an end, and a jounce bumper system. The jounce bumper system includes a jounce bumper having a first end and a second end. The first end of the jounce bumper coupled to a second, different portion of the vehicle. The jounce bumper system includes a rigid striker cap coupled to the end of the damper tube and having an outer flange spaced apart from a surface. The jounce bumper system also includes a flexible striker cap positioned adjacent to the second end of the jounce bumper and coupled to the outer flange of the rigid striker cap. The jounce bumper system includes an insert positioned between the flexible striker cap and the rigid striker cap. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0007]    The exemplary embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
           [0008]      FIG. 1  is a functional block diagram illustrating a vehicle that includes a damper having an insert in accordance with various embodiments; 
           [0009]      FIG. 2  is a perspective view of the damper of  FIG. 1 ; 
           [0010]      FIG. 3  is a cross-sectional view of the damper of  FIG. 2 , taken along line  3 - 3  of  FIG. 2 , which illustrates a jounce bumper system of the damper in a first position; 
           [0011]      FIG. 4  is a perspective view of the jounce bumper system of the damper of  FIG. 2 ; 
           [0012]      FIG. 5  is a cross-sectional detail view of the jounce bumper system of the damper of  FIG. 4 , taken along line  5 - 5  of  FIG. 4 ; and 
           [0013]      FIG. 6  is a schematic cross-sectional illustration of the jounce bumper system of the damper of  FIG. 4 , taken along line  5 - 5  of  FIG. 4 , in a second position. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    The following detailed description is merely exemplary in nature and is not intended to limit the application and uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. As used herein, the term module refers to any hardware, software, firmware, electronic control component, processing logic, and/or processor device, individually or in any combination, including without limitation: application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. In addition, the same reference numerals may be used to denote the same or similar components. 
         [0015]    With reference to  FIG. 1 , a vehicle  10  is shown including a damper in accordance with various embodiments. Although the figures shown herein depict an example with certain arrangements of elements, additional intervening elements, devices, features, or components may be present in an actual embodiment. It should also be understood that  FIG. 1  is merely illustrative and may not be drawn to scale. 
         [0016]    The vehicle  10  is shown to include wheels  14 , each fitted with a tire  16 . The wheels  14  are supported by a vehicle frame  18  via a suspension system shown generally at  20 . The suspension system  20  generally includes dampers  22 . Although the suspension system  20  is shown to be associated with only two wheels  14  for ease of description (e.g., either front wheels or rear wheels), it is appreciated that the suspension system  20  of the present disclosure is also applicable to a single wheel  14 , any pair of wheels  14  or all of the wheels  14  (plus others not shown) of the vehicle  10 . As will be discussed in greater detail herein, the dampers  22  includes a jounce bumper system  24  and a damper tube system  26 , which can provide energy dissipation and reduction in peak forces experienced by the vehicle frame  18  during an impact event. 
         [0017]    In one example, the vehicle  10  also includes a control module  28 , which is in communication with a portion of the suspension system  20  to control the activation of a portion of the suspension system  20 . For example, the control module  28  can be in communication with one or more of the dampers  22  to activate the dampers  22  in response to one or more sensed conditions associated with the vehicle  10 . Thus, the vehicle  10  can include one or more sensors that detect and measure observable conditions of the suspension system  20  and/or the vehicle  10  and generate sensor signals based on the observable conditions. Accordingly, the dampers  22  may actively respond to road surface conditions in real time based on signals received from the control module  28 . In alternative embodiments, the dampers  22  may also respond passively to road conditions. 
         [0018]    With reference to  FIGS. 2 and 3 , one of the dampers  22  is shown in greater detail. It should be note that while only one damper  22  is illustrated herein, the remaining dampers  22  may be similarly arranged. The damper  22  includes a first or top mounting bracket  30 , an upper spring seat  32 , a lower spring seat  34 , a biasing member or spring  36 , a dust tube or dust boot  38 , a second or lower mounting bracket  40 , a piston rod  42  ( FIG. 3 ), the jounce bumper system  24  ( FIG. 3 ) and the damper tube system  26 . It should be noted that the components of the damper  22  illustrated and described herein are merely exemplary, as different vehicle applications may require additional components or a modification of the herein described components. 
         [0019]    Generally, the top mounting bracket  30  can be coupled to a portion of the vehicle  10 , for example, the vehicle frame  18  using one or more mechanical fasteners  44 , as generally known to those skilled in the art. The lower mounting bracket  40  can be coupled to a portion of the vehicle  10 , such as a portion of the suspension system  20  using suitable fasteners, including, but not limited to, mechanical fasteners, as known to those skilled in the art. 
         [0020]    With reference to  FIG. 2 , the upper spring seat  32  and lower spring seat  34  cooperate to retain the spring  36 . Generally, the upper spring seat  32  is coupled adjacent to the top mounting bracket  30 , while the lower spring seat  34  is coupled to the damper tube system  26 . The spring  36 , in one example, is a coil spring, however, any suitable biasing element can be employed. Generally, the spring  36  is disposed substantially circumferentially about the dust boot  38  and the jounce bumper system  24 , and extends along a longitudinal axis  8  of the damper  22 . The spring  36  restores the damper  22  to an equilibrium height after an impact event. The dust boot  38  is coupled about the jounce bumper system  24 . The dust boot  38  covers and protects the jounce bumper system  24  from debris encountered during the operation of the vehicle  10 . The dust boot  38  can have any desired shape, and in one example, is substantially cylindrical. With reference to  FIG. 3 , the piston rod  42  is axially orientated (substantially parallel to the longitudinal axis  8  of the damper  22 ), and is coupled to the top mounting bracket  30 . The piston rod  42  is slidably coupled to a damper tube  46  of the damper tube system  26  through an opening  48  in a substantially flat upper end  46 ′ of the damper tube  46 . 
         [0021]    With reference to  FIGS. 3 and 4 , the jounce bumper system  24  includes a jounce bumper  50 , a first or upper mount  52 , a flexible striker cap  54 , a rigid striker cap  56  and an insert  58 . The jounce bumper system  24  assists in absorbing forces experienced by the vehicle  10  during an impact event. The jounce bumper  50  is formed of a suitable energy absorbing material, including, but not limited to, a polyurethane foam rubber. With reference to  FIGS. 4 and 5 , the jounce bumper  50  is substantially cylindrical, and tapers from a first end  60  to a second end  62 . The jounce bumper  50  includes a central bore  64 , which extends from the first end  60  to the second end  62 . The bore  64  is defined along the longitudinal axis  8 , and receives the piston rod  42  therethrough. The first end  60  of the jounce bumper  50  is coupled to the upper mount  52 . The upper mount  52  couples the jounce bumper system  24  to the top mounting bracket  30 . In addition, the jounce bumper  50  has a height  50 ′, which facilitates the desired amount of energy absorption for the jounce bumper  50 . It should be noted, however, that the shape and size of the jounce bumper  50  illustrated and described herein is merely exemplary, and the shape and size of the jounce bumper  50  may vary for different vehicular applications. 
         [0022]    The second end  62  of the jounce bumper  50  is adjacent to the flexible striker cap and contacts the flexible striker cap  54  in response to an impact event to absorb energy. Generally, the flexible striker cap  54  comprises any suitable flexible material including, but not limited to, a thermoplastic or thermosetting elastomeric polymer. In one embodiment, flexible striker cap  54  comprises a thermoplastic polyurethane (TPU) foam. The flexible striker cap  54  generally circumscribes and is slidably coupled to piston rod  42 . The flexible striker cap  54  includes a substantially planar flange  63  coupled to an annular base portion  66  via a sidewall  68 . The flange  63 , sidewall  68  and base portion  66  cooperate to define an interior cavity  70 , such the flexible striker cap  54  has a substantially U-shaped cross section. The cavity  70  is sized such that the flexible striker cap  54  fits over and about the rigid striker cap  56 , with the insert  58  received between a first, interior side  72  of the flange  63  and a surface  56 ′ of the rigid striker cap  56 . In one example, the interior side  72  of the flange  63  includes a groove  74 , which receives the insert  58 . 
         [0023]    A second, exterior side  75  of the flange  63  engages the jounce bumper  50  during impact events. An end of the base portion  66  includes a lip  66 ′, which overlaps an outer flange  76  of the rigid striker cap  56 . The overlap between the base portion  66  and the outer flange  76  serves as a mount for flexible striker cap  54  on the rigid striker cap  56 , and thus, the damper tube  46 . 
         [0024]    The rigid striker cap  56  may comprise any suitable structurally rigid material such as any steel alloy including stainless steel. The rigid striker cap  56  is conformably coupled to the upper end  46 ′ of the damper tube  46  and moves axially in unison therewith, and has an opening for slidable coupling to the piston rod  42 . 
         [0025]    The insert  58  is coupled to the flexible striker cap  54 , so as to be disposed in the groove  74  of the cavity  70 . In one example, the insert  58  may be press-fit into the groove  74  of the cavity  70  to couple the insert  58  to the flexible striker cap  54 . The insert  58  is substantially annular, and defines an opening  80  that extends along the longitudinal axis  8  of the damper  22 . The insert  58  comprises any suitable resilient, energy absorbing or damping material, including, but not limited to, polyurethane foam rubber. The insert  58  includes a first end  82  and a second end  84 , with the opening  80  extending through the insert  58  from the first end  82  to the second end  84 . In one example, the opening  80  has a diameter that ranges from about 36 millimeters to about 38 millimeters. Generally, the insert  58  has a thickness that ranges from about 20 millimeters to about 22 millimeters. It should be noted that these dimensions of the insert  58  are merely exemplary, as the insert  58  may have any suitable shape and dimension necessary for a given vehicular application. 
         [0026]    The first end  82  of the insert  58  includes a notch  86 . The notch  86  is generally defined adjacent to an inner surface  88  of the insert  58 , and in one example, extends about a periphery or circumference of the opening  80 . The notch  86  cooperates with the groove  74  to couple or secure the insert  58  within the flexible striker cap  54 . The second end  84  of the insert  58  includes a recess  90 . The recess  90  is defined on an outer surface  92  of the insert  58  and generally extends about a periphery or circumference of the insert  58 . The recess  90  is generally concave, however, the recess  90  can have any desired shape. The recess  90  provides additional clearance for the deformation of the insert  58  during an impact event. 
         [0027]    Generally, during an impact event, the insert  58  deforms to fill the cavity  70  of the flexible striker cap  54  to enable the jounce bumper system  24  to absorb additional energy. In addition, the insert  58  improves the durability of the flexible striker cap  54  by reinforcing the flexible striker cap  54  during an impact event, thereby reducing the strain on the flexible striker cap  54  during an impact event. In one example, the addition of the insert  58  in the jounce bumper system  24  was shown to improve energy absorption of the jounce bumper system  24  by about 20% when compared to a jounce bumper system without an insert  58 . Generally, the insert  58  absorbs about 50 Joules (J) of energy during an impact event, thereby increasing the energy absorption of the damper  22  by about 50 J. 
         [0028]    With reference back to  FIG. 3 , the damper tube system  26  includes the piston rod  42  and the damper tube  46 . Generally, the damper tube  46  includes a predetermined amount of a suitable fluid, such as a hydraulic fluid, which can be moved or compressed by the piston rod  42  to absorb and/or dissipate energy during the operation of the vehicle  10 . 
         [0029]    During operation, with reference to  FIG. 3 , the piston rod  42  oscillates in and out of the damper tube  46  in a well-known manner to dampen relative motion between connecting suspension members. The spring  36  also compresses and expands resiliently in concert with these oscillations. During normal driving conditions that do not produce excessive jounce, the second end  62  of the jounce bumper  50  and the second, exterior side  75  of the flange  63  of flexible striker cap  54  are in a first position, and remain separated by a distance that varies in accordance with the relative motion between the piston rod  42  and the damper tube  46 , as illustrated in  FIG. 3 . In a second position, during an impact event characterized by excessive jounce, the second end  62  of the jounce bumper  50  and the flexible striker cap  54  contact and deformably engage, absorbing at least part of the energy generated by the impact. This contractive motion may continue accompanied by additional deformation of the insert  58  until the jounce bumper  50 , the insert  58  and the flexible striker cap  54  each reach a maximum axial deformation, as illustrated in  FIG. 6 . For severe impact events wherein such maximum deformation is achieved, further jounce motion is prevented by the rigidity of the upper mount  52  and the rigid striker cap  56 . The overlapping of the base portion  66  with the outer flange  76  of the rigid striker cap  56  reduces the overall stack height or vertical space required by the flexible striker cap  54  enabling greater energy absorption per unit volume. 
         [0030]    The insert  58  stabilizes the amount of strain experienced by the flexible striker cap  54  by controlling the shape of the flexible striker cap  54  during deformation caused by jounce events. The insert  58  also increases the energy absorption capabilities of the flexible striker cap  54  by at least about 50 Joules (J). This results in increased durability and increased performance of the flexible striker cap  54 . 
         [0031]    While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof.