Abstract:
A vehicle suspension mounting structure and method can include a control arm connected to a bushing via a fastener rod and the method of connecting the same. The bushing can be attached to a portion of the vehicle frame. The fastener rod can be inserted into a cavity in the control arm such that the fastener rod extends away from the control arm and is prevented from being removed from the cavity in the control arm by a lip provided at a proximal end (relative to the control arm) of the fastener rod. The mounting structure and method can provide a safer and stronger connection between the control arm and bushing. In addition, serviceability can be improved and cost savings can be realized in some cases.

Description:
BACKGROUND 
     1. Field 
     The presently disclosed subject matter relates to a vehicle suspension system and a method of mounting a control arm of the suspension system to a vehicle frame. More particularly, the disclosed subject matter relates to a vehicle suspension system in which the control arm is attached by a fastening rod that extends from a cavity in the control arm and is connected via bushing to the vehicle frame. The rod can include a stopping structure configured to prevent the rod from passing completely through the cavity located on the control arm. 
     2. Brief Description of the Related Art 
     Typical vehicle suspension systems often require a great number of attachment mechanisms, and a great deal of space. The high number of components and their complex shapes also add cost and weight to a vehicle. In addition, the large volume required for these components also creates restrictions in vehicle design and also creates problems during repair in terms of added time required due to limited access to components, and added cost due to this added repair time and multiple part requirements. One area of concern is how each component is attached to the frame of a vehicle, particularly the suspension system components. 
     The vehicle suspension system connects the wheel mount structure with the vehicle frame. The suspension also controls a position of a tire with respect to the vehicle body for its ideal position during operation of the vehicle, and thus ensures optimal handling safety. It also prevents the wheel&#39;s axle/shaft from directly transmitting an impact or vibration from the road surface to the vehicle frame and in this way prevents damage of the vehicle cargo and improves the ride comfort for the vehicle passengers. Accordingly, the connection of the upper and lower portions of the vehicle&#39;s suspension system generally is made to be flexible to absorb the impact from the road surface, and to simultaneously moderate various forces applied to the vehicle&#39;s wheels. 
     Vehicle suspension systems typically include a complicated set of linkages, pneumatic devices, and springs that are designed to provide a smooth and relatively controlled ride for a vehicle. For example, a four bar linkage suspension can include lower and upper control arms connected on each side of the frame of a vehicle. The control arms are rotatably connected to the vehicle frame (e.g., by a “bar” type pivot/connecting device) so that they can rotate and move substantially vertically with respect to the vehicle frame. A knuckle typically connects each of the lower control arms to a respective upper control arm and a wheel mount structure can be attached to the knuckle. Thus, the wheel, when mounted, is permitted to move in a vertical direction relative to the vehicle frame. 
     The manner in which each of the components of a vehicle suspension system is connected to the frame of the vehicle and to each other has not typically been given a great deal of consideration other than to ensure proper functionality. For example, the control arms in a suspension system can be mounted in a variety of ways to the frame of a vehicle. The means of attachment can affect performance, safety, ease of serviceability and overall cost for a vehicle suspension system. 
     The control arms are specifically designed and positioned to allow the steering knuckles to move in a prescribed three-dimensional arc. Typically, the inner ends of the lower control arm have pressed-in bushings. Bolts, which pass through the bushings, serve to attach the lower arm to the vehicle frame. This is typically accomplished by pressing the bolt into the outer edge of the lower arm to simplify production of the parts. However, when an external force larger than a frictional force is applied to the bolt, the bolt can dislodge and retract from the same direction on the vehicle. 
     As shown in  FIG. 5 , a cross-sectional view of a conventional fastening mechanism can be provided where a fastener rod  25  is pressed in from the outer edge of a control arm  27  so that the fastener bolt shaft  28  is fed into the control arm cavity  29 . This conventional fastening mechanism does not prevent the fastener bolt  25  from being dislodged and pulled out from the control arm  27 . This method is typically used when the lower arm is made from a relatively lightweight material, such as aluminum, and it is thus necessary to use a bolt of relatively heavier weight material, such as steel, to connect to the bearing and vehicle frame. If the lower arm is made from a relatively heavy weight material, such as steel, a bolt may not even be necessarily used. For example, a rod like connection structure for connecting the lower control arm to the bushing and thus to the vehicle frame could be integrally formed with the steel lower control arm, or could be welded directly to the steel lower control arm. 
     Thus, other designs of mounting the lower arm exist wherein the fasteners are welded onto the arm or machined directly out of the arm material, integrating the arm and fastener into one piece. However, if the fastener is made from the same lightweight material as the lower arm, safety could be compromised, since the fastener undergoes a great deal of stress and is typically constructed from a relatively strong material. Typical mounting designs require heavyweight material for the connection between the lower control arm, bushing and vehicle frame. 
     Another example of a typical suspension system includes that disclosed in U.S. Pat. No. 5,938,220 (the &#39;220 patent), which discloses a pivot bushing for a McPherson Type Suspension. The &#39;220 patent describes a suspension arm of a three-point type. The suspension arm includes an outer anchoring point (for mounting of a lower bearing of a spring strut) and two inner anchoring points in the form of pivot means for pivotal mounting of the suspension arm to the vehicle body. The front pivot means is formed by a bushing extending essentially in the longitudinal direction of the vehicle and comprises a sleeve formed in the suspension arm. An elastic bushing element is inserted in the sleeve and is also shaped as a sleeve. The screw and bushing element and their guiding sleeve form an essentially conventional pivot means with the screw serving as a pivot axis. 
     There exists a need to provide a mount structure and method for mounting a lower control arm of a vehicle suspension system such that safety, cost-effectiveness, a ease of serviceability, are achieved. 
     SUMMARY 
     In accordance with an aspect of the disclosed subject matter, a vehicle suspension arm mounting arrangement can include a control arm, a bushing, and a fastening bolt having a stopping means, wherein the fastening bolt is mounted in a rear cavity of the lower control arm through the bushing, and wherein a threaded end of the fastening bolt protrudes from the rear cavity through the bushing, and a fastening nut secures the threaded end of the fastening bolt against the bushing. 
     In another aspect of the disclosed subject matter, the vehicle suspension arm mounting arrangement employs a stopping means formed as a fastening bolt lip. 
     In a further aspect of the disclosed subject matter, the vehicle suspension arm mounting arrangement can include a lower control arm and fastening bolt that are integrated into a single unit. 
     According to another aspect of the disclosed subject matter, the vehicle suspension arm mounting arrangement can include a lower control arm that is constructed of a material selected from a metal, a metal alloy, and a composite material. More specifically, the lower control arm material can be made from lightweight steel alloys, aluminum, aluminum alloys, composite resins, etc. 
     In another aspect of the disclosed subject matter, the fastening bolt is constructed of a material selected from a metal, a metal alloy, and a composite material. More specifically, the fastening bolt material can be made of steel, stainless steel, etc. 
     According to a further aspect of the disclosed subject matter, the vehicle suspension arm mounting arrangement can include a lower control arm, a bushing, and a fastening bolt having a lip, wherein the fastening bolt is mounted in a rear cavity of the lower control arm through the bushing, and wherein a threaded end of the fastening bolt protrudes from the rear cavity through the bushing, and the lip of the fastening bolt contacts an inner end of the rear cavity, and a fastening nut secures the threaded end of the fastening bolt against the bushing. 
     Still other features and attendant characteristics of the disclosed subject matter will become apparent to those skilled in the art from a reading of the following detailed description of embodiments, and taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosed subject matter will now be described in more detail with reference to exemplary embodiments of the apparatus and method, given only by way of example, and with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a vehicle suspension system employing a lower control arm and fastening structures made in accordance with principles of the disclosed subject matter; 
         FIGS. 2A and 2B  are detailed exploded perspective views of the lower control arm with fastening structures as shown in  FIG. 1 ; 
         FIGS. 3A and 3B  are detailed perspective views of the lower control arm with fastening structures as shown in  FIG. 1 ; 
         FIG. 4  is a partial sectional view of the lower control arm with fastening structures of  FIG. 1 ; and 
         FIG. 5  is a cross-sectional view of a conventional art attachment structure. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Referring to the drawing figures, like reference numerals designate identical or corresponding elements throughout the several figures. 
       FIG. 1  shows a perspective view of a vehicle suspension system employing a lower control arm  1  and fastening structures made in accordance with the principles of the disclosed subject matter. The vehicle suspension system can include a wheel mount  2  that is connected to the vehicle frame  3  via a lower control arm  1  and an upper link assembly, such as a strut  4 . The wheel mount  2  can be formed as a knuckle that is configured to hold a drive axle therein. 
     The control arm  1  can include a first distal extension portion  111  and a second distal extension portion  112  (as shown in  FIG. 2A ). The first and second distal extension portions  111  and  112  are joined together by an intermediary portion  113  to form a generally L-shaped control arm structure. The intermediary portion  113  can be configured for attachment to the vehicle frame  3  by, for example, an integral bearing and bushing into which a connective structure extending from the vehicle frame  3  can be attached. The first distal extension portion  111  can also be configured for attachment to the vehicle frame  3 , as described in more detail below, such that the control arm  1  can rotate about a longitudinal axis of the first distal extension portion  111  and the central axis of the bearing/bushing of the intermediary portion  113 . The second distal extension portion  112  can extend from the intermediary portion  113  and include attachment structure for attaching to the wheel mount structure  2  of the vehicle. The first distal extension portion  111  and a second distal extension portion  112  can be configured to extend continuously from the intermediary portion  113  in such a manner as to form a generally L-shaped control arm structure. 
     The first distal extension portion  111  of the control arm  1  can be attached to the vehicle frame  3  via a fastening rod  17  that connects to a bushing  5  located within a bearing opening  6 . The bushing  5  and bearing  13  can both reside within an open end of a multi-mount suspension bracket  7  that attaches directly to the vehicle frame  3 . The bearing  13  and bushing  5  of the multi-mount suspension bracket  7  are located outside and adjacent a first extension portion  111  of the lower control arm  1 , and the vehicle frame  3  is often generally parallel to the first extension portion  111  of the lower control arm  1  along the longitudinal axis of the vehicle. However, this specific relationship between the first extension portion  111  and the vehicle frame  3  is dependent on the type of vehicle and vehicle frame being used, and can vary accordingly. 
     The fastening rod  17  can have a distal end that includes a fastening structure formed, for example, as a threaded end portion  23 . A proximal end of the fastening rod  17  can include a stopping structure  19  that locks the fastening rod  17  to the control arm  1  and prevents the fastening rod  17  from passing totally through the control arm housing  21  and through-hole  22  when assembled. The fastening rod can be inserted into the control arm housing  21  by press-fitting or sliding the fastening rod therein. If necessary, a fitting sleeve or other structure can be provided to ensure a snug fit between the fastening rod  17  and the control arm housing  21 . 
     The multi-mount suspension bracket  7  can include a plurality of openings in which fasteners may be permanently or removably inserted for connecting the multi-mount suspension bracket  7  to the vehicle frame  3 . One or more of the fasteners can optionally pass through a removably mounted stabilizer bar clamp bracket  11  and also pass through one or more of the multi-mount suspension bracket openings to secure a stabilizer bar  12  to the vehicle frame  3 . 
       FIGS. 2A and 2B  show an exploded view of a multi-mount suspension bracket  7  and its connection to a lower control arm  1  through a bushing  5 . The multi-mount suspension bracket  7  can include a first opening  8 , a second opening  9 , and a third opening  10  which are all substantially parallel to each other. Each of the first, second, and third openings  8 ,  9 ,  10  can be tapped or untapped, depending on the desired operation/need. The first opening  8  and third opening  10  can be formed as through-holes for connection to the vehicle frame  3  via a suitable fastener, such as a bolt. The second opening  9  is shown as formed with a tapped hole for connection to a stabilizer bar clamp bracket  11 . A fastening rod  17  is slideably mounted through a lower control arm housing  21  that is formed as a lower control arm through-hole  22  in this example. The fastening rod  17  can have a threaded end  23  which passes through the bushing  5  located in the open end of the multi-mount suspension bracket  7 . A fastening rod stopping structure  19  can be provided on a distal portion of the fastening rod  17  such that it is located opposite a proximal portion of the fastening rod  17  that includes the fastening bolt threaded end  23 . The fastening rod stopping structure  19  can have a diameter greater than the diameter of the fastening rod shaft  20  and can act as a stopping means to prevent the fastening rod  17  from being pulled through the control arm housing  21 . The fastening bolt threaded end  23  protrudes from the end of the first distal portion  111  of the lower control arm  1 . A fastening nut  18  or other attachment structure can be attached to the protruding fastening rod threaded end  23  that emerges from the bushing  5  to fixedly secure the bushing  5  to the lower control arm  1 . 
       FIG. 3A  is a detailed perspective view of the control arm  1  attached to bushing  5 . This perspective view shows the fastening rod stopping structure  19  secured in the control arm housing  21 . The fastening rod stopping structure  19  rests against the control arm housing inner end  24  to secure the fastening rod  17  from movement along its longitudinal axis. The fastening rod threaded end  23  protrudes through the lower control arm through-hole  22  and into bushing  5  for attachment via a fastening nut  18 . When assembled, the bushing  5  is located outside the control arm  1  and control arm housing  21  and at an end of the first distal portion  111  of the control arm  1 . The multi-mount suspension bracket  7  is fastened about the bushing  5  to attach the bushing to the vehicle frame  3 . 
       FIG. 3B  is a detailed perspective view which is 180° rotated with respect to the  FIG. 3A  perspective view. This view shows the bushing  5  secured to the lower control arm  1  via the fastening nut  18  that is attached to the fastening rod threaded end  23 . 
       FIG. 4  shows a partial sectional view of the fastening rod  17  connection arrangement with the bushing  5 , bearing  13  and lower control arm  1 . The fastening rod  17  is located in the control arm housing  21  and a fastening nut  18  can be used to secure the fastening bolt threaded end  23  that passes through the multi-mount suspension bracket  7  to the bushing  5  and bearing  13 . This sectional view also shows the fastening rod stopping structure  19  resting against the control arm housing inner end  24  where the fastening rod stopping structure  19  has a greater diameter than that of the fastening rod shaft  20  located in the control arm housing  21 . 
     During assembly, the fastening rod  17  can be inserted into the control arm housing  21  from the rear of the lower control arm  1  (from a location closer to the intermediate portion  113  of the control arm  1 ) and then pushed towards the first distal portion  111  of the control arm  1 . Subsequently, the fastening rod  17  and the bushing are connected together by inserting the fastening rod  17  into the bushing  5 , e.g., by either pushing the fastening rod  17  into the bushing  5  or pushing the bushing  5  onto the fastening rod  17 . Thus, the fastening bolt threaded end  23  protrudes through the lower control arm through-hole  22  and the bushing  5 . A fastening nut  18 , such as a lock nut or the like, can then be tightened onto the fastening bolt threaded end  23 , which secures the bushing  5  to the lower control arm  1 . Further, securing the fastening nut  18  to the fastening bolt threaded end  23  causes the fastening rod stopping structure  19  to lodge against the control arm cavity inner end  24 , further securing the bushing  5  to the lower control arm  1 . The fact that the fastening rod stopping structure  19  can be directly or indirectly lodged against the control arm cavity inner end  24  prevents the fastening rod  17  from being pulled through the lower control arm through-hole  22  and the bushing  5 . Thus, this exemplary construction affords greater degrees of safety and serviceability for a vehicle suspension system. 
     Various and different materials and configurations are contemplated for use with the vehicle suspension system and method described herein. For example, the fastening rod  17  can be fabricated from various metals, metal alloys, composite materials, or the like, depending upon the particular application and relative strength required for the fastening rod  17 . The fastening nut  18  can also be similarly fabricated from metals such as steel, steel alloys, aluminum, other metals, and composite materials, although other materials may also be used. Furthermore, the control arm  1  can be made from a lightweight metal (as compared to the fastening rod  17 ) such as aluminum, aluminum alloys, steel, steel alloys, composite materials and resins, etc. 
     While certain embodiments of the invention are described above, it should be understood that the invention can be embodied and configured in many different ways without departing from the spirit and scope of the invention. For example, some or all of the separate attachment structures can be replaced with welds for simultaneous attachment between various structures, such as between the vehicle frame and mount brackets, etc. 
     The vehicle suspension system can be any type of suspension system in which a bushing can be mounted to a control arm, and is not limited to a four bar or two bar vehicle suspension system. 
     It should be noted that the control arm  1  is shown as an L-shaped control arm. However, the principles of the disclosed subject matter could be incorporated into differently shaped control arms. In addition, although the bushing  5  is depicted as a typical elastic bushing surrounded by a bearing  13  in the figures, there are many other various connection structures that could be used as the bushing  5  without departing from the spirit of the disclosed subject matter. For example, the bushing  5  can be a fluid coupling device, a spring coupling device, or a ball bearing coupling device. 
     With regard to the fastening rod  17 , the rod  17  can be formed as a bolt, a spline, a bar, a rivet, a stud or other structure that can perform the functions as described above with respect to the fastening rod  17 . In addition, although the housing  21  in which the fastening rod  17  is inserted is depicted as a cavity in the first distal portion  111  of the control arm  1 , the housing  21  can take on many other various forms. For example, the housing  21  can be formed separately from the control arm  1  and attached thereto by a fastening structure. In addition, the housing  21  can be formed by separate cylindrical or partially cylindrical structures either formed in or by the control arm  1 . The cavity or opening in which the fastening rod  17  resides is not required to be totally encapsulating and may be formed as a partial through-hole or partial cavity that only partially encircles the fastening rod  17 . 
     The fastening rod  17  includes a stopping structure  19  that is formed as a lip in the appended figures. However, it is contemplated that the stopping structure  19  can be formed in various different ways. In particular, the stopping structure  19  can be a slight irregularity in the proximal end of the fastening rod  17  that allows the rod  17  to lock with respect to the control arm housing  21 . In addition, a separate nut, a bolt head, a cotter pin, extension, crimpable portion, etc. can be provided as the stopping structure  19  to lock the rod  17  in the housing  21 . 
     The fastening structure of the fastening rod  17  is depicted as a threaded portion  23 . However, other fastening structures can be used without departing from the spirit of the disclosed subject matter. For example, a cotter pin, a weld, an adhesive, a rivet, a crimpable portion, etc., can be provided at the distal end of the fastening rod  17  to provide the fastening structure that allows the bushing  5  and multi-mount  7  to be secured to the control arm  1 . Likewise, different structures are contemplated for use as the stopping structure located at the proximal end of the fastening rod, as described above. Furthermore, the longitudinal axis of the fastening rod  17  can be parallel with, coincident with, or substantially parallel with the longitudinal axis of the first distal extension portion  111  of the control arm. 
     While the invention has been described in detail with reference to exemplary embodiments thereof, it will be apparent to one skilled in the art that various changes can be made, and equivalents employed, without departing from the scope of the invention. Each of the aforementioned conventional are documents is incorporated by reference herein in its entirety.