Abstract:
The present disclosure relates to a strut assembly for use with a vehicle. The strut assembly has a shock absorber having a shock absorber tube, a lower spring seat, a tubular member and a coil spring. The lower spring seat supports one end of the spring and includes a tubular member having an inner wall surface, and is configured to receive the shock absorber tube therein. The lower spring seat has an annular member extending radially outwardly from the tubular member with a surface for supporting the one end of the coil spring thereon. The tubular member has a portion constructed to deform and collapse in response to a predetermined excessive force experienced by the shock absorber.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/029618, filed on Jul. 28, 2014. The entire disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to a spring seat, and more particularly to a lower spring seat for supporting a coil spring of a vehicular suspension system. 
       BACKGROUND 
       [0003]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0004]    Strut-type suspension systems are well known in the motor vehicle industry. A telescopic strut assembly normally incorporating a hydraulic damper is used as one of the locating members for the wheel of the motor vehicle. A strut assembly typically includes a coil spring concentrically disposed around a shock absorber. The coil spring extends between an upper spring seat which is a part of a top mount assembly for the strut assembly and a lower spring seat which is attached to the shock absorber of the strut assembly. 
         [0005]    The lower spring seat can be a single piece made of metal or plastic. A plastic spring seat is light weight than its metal counterpart. The lower spring seat typically includes an annular member that supports the lower end of the spring and a tubular member which extends from the annular member. The tubular member is designed to interface with an outer tube of the shock absorber. For example,  FIG. 1  illustrates a lower spring seat  200 , which is made of plastic, disposed about an outer tube  202  of a shock absorber. The lower spring seat  200  is retained by a support ring  204  which is welded to the outer tube  202 . More particularly, a tubular member  206  of the lower spring seat  200  abuts the support ring  204 . 
         [0006]    The spring seat supports and maintain the correct position of the spring under various driving conditions of the vehicle. The spring seat resists braking loads, wear, abrasion, changing loads and hits by stones and other debris. During severe impact in which the spring fails, the spring seat is designed to withstand and support the spring. For example, a lower spring seat made of plastic may include a steel or rubber pad disposed on the lower spring seat which absorbs the energy in the event the spring fails. To avoid using such a pad on the whole lower spring seat, a spring sleeve is also mounted on the spring. The spring sleeve delays any failure due to early corrosion. However, the use of the added components like the pad and the spring sleeve further increases the cost of the lower spring seat and the overall cost of a strut assembly in which it is incorporated. 
       SUMMARY 
       [0007]    This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
         [0008]    In one aspect the present disclosure relates to a strut assembly for use with a vehicle. The strut assembly may include a shock absorber having a shock absorber tube, a lower spring seat, a tubular member and a coil spring. The lower spring seat may support one end of the spring and include a tubular member having an inner wall surface, and configured to receive the shock absorber tube therein. The lower spring seat may also include an annular member extending radially outwardly from the tubular member and having a surface for supporting the one end of the coil spring thereon. The tubular member may have a portion constructed to deform and collapse in response to a predetermined excessive force experienced by the shock absorber. This allows the excessive force to be accommodated by the strut assembly without significantly affecting an integrity of the annular member, thus enabling the coil spring to be retained by the strut assembly. 
         [0009]    In another aspect the present disclosure relates to a strut assembly for use with a vehicle. The strut assembly may include a shock absorber having a shock absorber tube, a coil spring and a lower spring seat. The lower spring seat may be used for supporting one end of the spring. The lower spring may include a tubular member having an inner wall surface, and configured to receive the shock absorber tube therein, as well as a support ring. The support ring may be secured to a portion of the shock absorber tube and disposed adjacent the tubular member to support the tubular member thereon. The tubular member may further include a primary member and a reinforcement member on the inner wall surface. The primary member is configured to deform, so as to be compressed, in response to a predetermined excessive force experienced by the shock absorber, such that the tubular member is supported by the reinforcement member on the support ring after the deformation. 
         [0010]    In still another aspect the present disclosure relates to a strut assembly for use with a vehicle. The strut assembly may include a shock absorber having a shock absorber tube, a coil spring and a lower spring seat for supporting one end of the spring. The lower spring seat may include a tubular member having an inner wall surface which is configured to receive the shock absorber tube therein. A metallic support ring is included which is fixed securely to a portion of the shock absorber tube, and disposed adjacent the tubular member to support the tubular member thereon. The tubular member further includes a primary member and a reinforcement member on the inner wall surface. The primary member is configured to deform, so as to be compressed, in response to a predetermined excessive force experienced by the shock absorber, such that the tubular member is supported by the reinforcement member on the support ring after the deformation. The reinforcement member includes at least one of a tapering wall portion or a series of interspersed, circumferential grooves and ribs. 
         [0011]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0012]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0013]      FIG. 1  illustrates a prior art assembly of a lower spring seat and a support ring disposed about a tube of a shock absorber; 
           [0014]      FIG. 2A  illustrates in a strut assembly incorporating a lower spring seat in accordance with one embodiment of the present disclosure; 
           [0015]      FIG. 2B  illustrates a first embodiment of a lower spring seat of the present disclosure; 
           [0016]      FIG. 3  illustrates an enlarged view of a primary member and a reinforcement member of the lower spring seat of  FIG. 2B ; 
           [0017]      FIG. 4  illustrates a position of the lower spring seat relative to a support ring before and after a deformation of the primary member; 
           [0018]      FIG. 5  illustrates a second embodiment of a lower spring seat of the present disclosure; 
           [0019]      FIG. 6  illustrates an enlarged view of a primary member and a reinforcement member of the lower spring seat of  FIG. 5 ; 
           [0020]      FIGS. 7A and 7B  illustrate a third embodiment of a lower spring seat of the present disclosure; 
       
    
    
       [0021]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0022]    The present disclosure will now be described more fully with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application or uses. A vehicle includes a suspension system (front and rear suspension) having a strut assembly  1  in accordance with one embodiment of the present disclosure, as shown in  FIG. 2A , at each of the wheels. The strut assembly  1  includes a shock absorber  2  and a coil spring  3  disposed concentrically around the shock absorber. The coil spring  3  is disposed between an upper spring seat  4  and a lower spring seat  10 . The present disclosure relates in particular to the design and construction of the lower spring seat  10 . 
         [0023]      FIG. 2B  illustrates the lower spring seat  10  in greater detail. The lower spring seat  10  has an annular member  12 , a tubular member  14  extending from the annular member  12 , and a support ring  16 . When installed in the strut assembly, the coil spring sits on the annular member  12  of the lower spring seat  10 , and the tubular member  14  and the support ring  16  are concentrically disposed around a tube of the shock absorber. The support ring  16  is made of metal and is fixedly attached to the tube by way of, for example, welding, brazing, etc. The tubular member  14  abuts the support ring  16  such that the support ring  16  supports and fixes the position of the lower spring seat  10  along the tube of the shock absorber. 
         [0024]    The lower spring seat  10  is made of plastic. The lower spring seat  10  is designed to absorb forces exerted by the coil spring during various operating conditions, such as in full compression, rebound and jounce (i.e., normal operating conditions). Furthermore, the lower spring seat  10  is designed to deform when a severe load is received, such as when the coil spring fails due to a severe impact. The deformation of the lower spring seat  10  dissipates the energy of the impact without harming the rest of the components of the strut assembly. 
         [0025]    To enable it to absorb energy during normal operating conditions and to deform at a severe operating condition, the lower spring seat  10  includes a primary member  20  and an energy dissipation member  22  ( FIGS. 2 and 3 ). The primary member  20  and the energy dissipation member  22  are part of the tubular member  14 . The primary member  20  is a lower seat of the tubular member  14  which abuts with the support ring  16 . More particularly, an inner wall  24  of the tubular member  14  extends from a first end  26  to a second end  28 . The support ring  16  abuts the second end  28 , which is part of the primary member  20 . 
         [0026]    The energy dissipation member  22  is positioned above the primary member  20 , such that the primary member  20  is between the energy dissipation member  22  and the support ring  16 . The energy dissipation member  22  has an angled wall  30  which circumferentially extends along the inner wall  24  of the tubular member  14 . More particularly, the angled wall  30  tapers toward the primary member  20 . 
         [0027]    The primary member  20  transfers the load from the coil spring to the support ring  16  during normal operating conditions. When a severe impact is received, such as an impact that causes the failure of the coil spring, the primary member  20  is designed to deform. Specifically, with reference to  FIG. 4 , the primary member  20  collapses, such that the lower spring seat  10  moves down and the support ring  16  interfaces with the energy dissipation member  22 . Due to the angled wall  30  and the friction between the lower spring seat  10  and the support ring  16 , the energy dissipation member  22  clamps on the support ring  16 . The interference between the energy dissipation member  22  and the support ring  16  absorbs energy to prevent the lower spring seat  10  from failing and, therefore, provides temporary positional support to the coil spring. 
         [0028]      FIGS. 5 and 6  illustrate a lower spring seat  50  in a second embodiment. Similar to the lower spring seat  10 , the lower spring seat  50  includes an annular member  52  and a tubular member  54 . The tubular member  54  abuts with the support ring  16 . The lower spring seat  50  further includes a primary member  60  and an energy dissipation member  62 . The primary member  60  and the energy dissipation member  62  are part of the tubular member  54 . 
         [0029]    Similar to the primary member  20 , the primary member  60  is a lower seat of the tubular member  54  which abuts with the support ring  16 . More particularly, an inner wall  64  of the tubular member  54  extends from a first end  66  to a second end  68 . The support ring  16  abuts with the second end  68  which is part of the primary member  60  of the tubular member  14 . 
         [0030]    The energy dissipation member  62  is positioned above the primary member  60 , such that the primary member  60  is between the energy dissipation member  62  and the support ring  16 . The energy dissipation member  62  has multiple ribs  70  which circumferentially extend along the inner wall  64  of the tubular member  14 . More particularly, the ribs  70  include multiple grooves and teeth that are alternately arranged along the inner wall  64 . 
         [0031]    The primary member  60  and the energy dissipation member  62  operate in a similar manner as the primary member  20  and the energy dissipation member  22 , respectively. Specifically, the primary member  60  transfers load from the coil spring  3  to the support ring  16  during normal operating conditions. When a severe impact occurs, such as an impact which causes the failure of the coil spring  3 , the primary member  60  collapses. The lower spring seat  50  moves down and the support ring  16  interfaces with the energy dissipation member  62 . The friction and clamping between the ribs  70  of the energy dissipation member  62  and the support ring  16  absorbs the energy exerted on to the lower spring seat  50  after the deformation of the primary member  60 , thereby preventing or controlling further damage to the lower spring seat  50  and/or coil spring. 
         [0032]    In the first and second embodiments, the primary member and the energy dissipation member (either member  22  or member  62 ) are integrated with the lower spring seat. Alternatively, the energy dissipation member  22  or  62  may be made of a different material and attached to the lower spring seat. For example,  FIGS. 7A and 7B  illustrate a lower spring seat  80  which has an annular member  82  and a tubular member  84 . The tubular member  84  includes a primary member  90  and an energy dissipation member  92 . The primary member  90  is made of the same material as the lower spring seat  80  (e.g., plastic). Based on the material, the structure of the primary member  90  is designed to transmit normal loads from the coil spring  3  to the support ring  16  and to deform in the event of a high impact. 
         [0033]    The energy dissipation member  92  is made of a different material than the lower spring seat  80 . Since the energy dissipation member  92  absorbs energy after the deformation of the primary member  90 , the energy dissipation member  92  has softer characteristics than the primary member  90 . The structure and the material of the energy dissipation member  92  can be altered to achieve a desired rigidity. For example, if the material of the energy dissipation member  92  is plastic reinforced with glass fibers, which is harder than plastic, the structure of the energy dissipation member  92  is configured to provide the softer properties associated with energy dissipation member  92 . By incorporating a different material for the energy dissipation member  92 , the structural configuration of the energy dissipation member  92  is no longer limited by the material of the lower spring seat  80 . 
         [0034]    The lower spring seat of the present disclosure includes a first structure (i.e., primary member) that provides static strength when subjected to normal loads and collapses when subjected to an impact. When the first structure collapses, the energy from the impact dissipates such that the lower spring seat remains in substantially one piece for supporting the coil spring. The lower spring seat further includes a second structure (i.e., an energy dissipation member) that absorbs energy after the deformation of the first structure. The second structure provides temporary support to the lower spring seat which supports the coil spring, so that the vehicle is able to travel to a safe area, such as a garage. The lower spring seat preserves the lightweight benefits associated with plastic components without compromising on performance. 
         [0035]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. 
         [0036]    Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.