Patent Publication Number: US-9428046-B2

Title: Alignment and retention system for laterally slideably engageable mating components

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application Ser. No. 61/974,107, filed Apr. 2, 2014, which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The subject invention relates to the art of alignment systems, more particularly to an elastically averaged alignment system, and even more particularly to an elastically averaged alignment system providing six-way alignment of laterally slideably engageable mating components on which the alignment system is incorporated. 
     BACKGROUND 
     Currently, components, particularly vehicular components such as those found in automotive vehicles, which are to be mated together in a manufacturing process are mutually located with respect to each other by alignment features that are oversized and/or undersized to provide spacing to freely move the components relative to one another to align them without creating an interference therebetween that would hinder the manufacturing process. One example includes two-way and/or four-way male alignment features, typically upstanding bosses, which are received into corresponding female alignment features, typically apertures in the form of holes or slots. There is a clearance between the male alignment features and their respective female alignment features which is predetermined to match anticipated size and positional variation tolerances of the male and female alignment features as a result of manufacturing (or fabrication) variances. As a result, significant positional variation can occur between the mated first and second components having the aforementioned alignment features, which may contribute to the presence of undesirably large variation in their alignment, particularly with regard to the gaps and spacing between them. In the case where these misaligned components are also part of another assembly, such misalignments can also affect the function and/or aesthetic appearance of the entire assembly. Regardless of whether such misalignment is limited to two components or an entire assembly, it can negatively affect function and result in a perception of poor quality. 
     Accordingly, the art of alignment systems can be enhanced by providing an alignment and retention system or mechanism that can ensure precise two-way, four-way or six-way alignment and fastening of two components via elastic averaging of a plurality elastically deformable alignment and retention elements disposed in mating engagement with a plurality of corresponding alignment features. 
     SUMMARY OF THE INVENTION 
     In one exemplary embodiment of the invention, an elastically averaged alignment system includes a first component and a second component. The first component includes at least one of a first alignment feature fixedly disposed with respect to the first component, and at least one of a second alignment feature fixedly disposed with respect to the first component. The second component includes at least one of a third elastically deformable alignment element fixedly disposed with respect to the second component, and at least one of a fourth elastically deformable alignment element fixedly disposed with respect to the second component. The first and second components are laterally slidably engageable with each other. A respective one of the third elastically deformable alignment element is configured and disposed to interferingly, deformably and matingly engage with a respective one of the first alignment feature. A respective one of the fourth elastically deformable alignment element is configured and disposed to interferingly, deformably and matingly engage with a respective one of the second alignment feature. Portions of the third and fourth elastically deformable alignment elements when engaged with respective ones of the first and second alignment features elastically deform to an elastically averaged final configuration that aligns the first component relative to the second component in six planar orthogonal directions by averaging the elastic deformation of the respective elastically deformable alignment elements. 
     The above features and advantages and other features and advantages of the invention are readily apparent from the following detailed description of the invention when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features, advantages and details appear, by way of example only, in the following detailed description of embodiments, the detailed description referring to the drawings in which: 
         FIG. 1  depicts an assembly of a first component aligned and retained relative to a second component via an elastically averaged alignment and retention system, in accordance with an embodiment of the invention; 
         FIG. 2  depicts an isometric view of the first component of  FIG. 1  with a mating side of the first component visible, in accordance with an embodiment of the invention; 
         FIG. 3  depicts an isometric view of the second component of  FIG. 1  with a mating side of the second component visible, in accordance with an embodiment of the invention; 
         FIG. 4  depicts an expanded isometric view of an alignment feature of the first component, in accordance with an embodiment of the invention; 
         FIG. 5  depicts an expanded isometric view of an elastically deformable alignment element of the second component, in accordance with an embodiment of the invention; 
         FIG. 6  depicts a side view of the elastically deformable alignment element of  FIG. 5  elastically, deformably and matingly engaged with the alignment feature of  FIG. 4 , where the engagement surfaces are depicted overlapping to illustrate an interference fit therebetween, in accordance with an embodiment of the invention; 
         FIG. 7A  depicts a cross section view through a portion of the assembly of  FIG. 1 , in accordance with an embodiment of the invention; 
         FIG. 7B  depicts an expanded portion of the cross section view of  FIG. 7A , in accordance with an embodiment of the invention; and 
         FIG. 8  depicts a cross section view through another portion of the assembly of  FIG. 1 , in accordance with an embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. For example, the embodiments shown comprise vehicle components but the alignment system may be used with any suitable components to provide elastic averaging for precision location and alignment of all manner of mating components and component applications, including many industrial, consumer product (e.g., consumer electronics, various appliances and the like), transportation, energy and aerospace applications, and particularly including many other types of vehicular components and applications, such as various interior, exterior and under hood vehicular components and applications. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     As used herein, the term “elastically deformable” refers to components, or portions of components, including component features, comprising materials having a generally elastic deformation characteristic, wherein the material is configured to undergo a resiliently reversible change in its shape, size, or both, in response to application of a force. The force causing the resiliently reversible or elastic deformation of the material may include a tensile, compressive, shear, bending or torsional force, or various combinations of these forces. The elastically deformable materials may exhibit linear elastic deformation, for example that described according to Hooke&#39;s law, or non-linear elastic deformation. 
     Elastic averaging provides elastic deformation of the interface(s) between mated components, wherein the average deformation provides a precise alignment, the manufacturing positional variance being minimized to X min , defined by X min =X/√N, wherein X is the manufacturing positional variance of the locating features of the mated components and N is the number of features inserted. To obtain elastic averaging, an elastically deformable component is configured to have at least one feature and its contact surface(s) that is over-constrained and provides an interference fit with a mating feature of another component and its contact surface(s). The over-constrained condition and interference fit resiliently reversibly (elastically) deforms at least one of the at least one feature or the mating feature, or both features. The resiliently reversible nature of these features of the components allows repeatable insertion and withdrawal of the components that facilitates their assembly and disassembly. In some embodiments, the elastically deformable component configured to have the at least one feature and associated mating feature disclosed herein may require more than one of such features, depending on the requirements of a particular embodiment. Positional variance of the components may result in varying forces being applied over regions of the contact surfaces that are over-constrained and engaged during insertion of the component in an interference condition. It is to be appreciated that a single inserted component may be elastically averaged with respect to a length of the perimeter of the component. The principles of elastic averaging are described in detail in commonly owned, co-pending U.S. patent application Ser. No. 13/187,675, now U.S. Pat. No. 8,695,201, the disclosure of which is incorporated by reference herein in its entirety. The embodiments disclosed above provide the ability to convert an existing component that is not compatible with the above-described elastic averaging principles, or that would be further aided with the inclusion of an elastically averaged alignment and retention system as herein disclosed, to an assembly that does facilitate elastic averaging and the benefits associated therewith. 
     Any suitable elastically deformable material may be used for the mating components and alignment features disclosed herein and discussed further below, particularly those materials that are elastically deformable when formed into the features described herein. This includes various metals, polymers, ceramics, inorganic materials or glasses, or composites of any of the aforementioned materials, or any other combinations thereof suitable for a purpose disclosed herein. Many composite materials are envisioned, including various filled polymers, including glass, ceramic, metal and inorganic material filled polymers, particularly glass, metal, ceramic, inorganic or carbon fiber filled polymers. Any suitable filler morphology may be employed, including all shapes and sizes of particulates or fibers. More particularly any suitable type of fiber may be used, including continuous and discontinuous fibers, woven and unwoven cloths, felts or tows, or a combination thereof. Any suitable metal may be used, including various grades and alloys of steel, cast iron, aluminum, magnesium or titanium, or composites thereof, or any other combinations thereof. Polymers may include both thermoplastic polymers or thermoset polymers, or composites thereof, or any other combinations thereof, including a wide variety of co-polymers and polymer blends. In one embodiment, a preferred plastic material is one having elastic properties so as to deform elastically without fracture, as for example, a material comprising an acrylonitrile butadiene styrene (ABS) polymer, and more particularly a polycarbonate ABS polymer blend (PC/ABS). The material may be in any form and formed or manufactured by any suitable process, including stamped or formed metal, composite or other sheets, forgings, extruded parts, pressed parts, castings, or molded parts and the like, to include the deformable features described herein. The elastically deformable alignment features and associated component may be formed in any suitable manner. For example, the elastically deformable alignment features and the associated component may be integrally formed, or they may be formed entirely separately and subsequently attached together. When integrally formed, they may be formed as a single part from a plastic injection molding machine, for example. When formed separately, they may be formed from different materials to provide a predetermined elastic response characteristic, for example. The material, or materials, may be selected to provide a predetermined elastic response characteristic of any or all of the elastically deformable alignment features, the associated component, or the mating component. The predetermined elastic response characteristic may include, for example, a predetermined elastic modulus. 
     As used herein, the term vehicle is not limited to just an automobile, truck, van or sport utility vehicle, but includes any self-propelled, towed, or movable conveyance suitable for transporting or supporting a burden. 
     In accordance with an example embodiment of the invention, and with reference to  FIGS. 1-3 , an elastically averaged alignment system  10  includes a first component  100  having at least one of a first alignment feature  102  (individually herein referred to by reference numerals  102 . 1 ,  102 . 2  . . . ) fixedly disposed with respect to the first component  100 , or at least one of a second alignment feature  104  (individually herein referred to by reference numerals  104 . 1 ,  104 . 2  . . . ) fixedly disposed with respect to the first component  100 , and a second component  200  having at least one of a third elastically deformable alignment element  202  (individually herein referred to by reference numerals  202 . 1 ,  202 . 2  . . . ) fixedly disposed with respect to the second component  200 , and at least one of a fourth elastically deformable alignment element  204  (individually herein referred to by reference numerals  204 . 1 ,  204 . 2  . . . ) fixedly disposed with respect to the second component  200 . The first and second components  100 ,  200  are laterally slideably engageable with each other in a manner that will be described in more detail below. 
     With reference to  FIGS. 4-7B  ( FIG. 4  depicts an expanded view of detail  150  of  FIG. 2 ,  FIG. 5  depicts an expanded view of detail  250  of  FIG. 3 , and  FIG. 7B  depicts an expanded view of detail  300  of  FIG. 7A ) in combination with  FIGS. 1-3 , respective ones of the third elastically deformable alignment element  202  are configured and disposed to interferingly, deformably and matingly engage with associated respective ones of the first alignment feature  102 , and respective ones of the fourth elastically deformable alignment element  204  is configured and disposed to interferingly, deformably and matingly engage with a respective one of the second alignment feature  104 . Portions of the third and fourth elastically deformable alignment elements  202 ,  204  when engaged with respective ones of the first and second alignment features  102 ,  104  elastically deform to an elastically averaged final configuration that aligns the first component  100  relative to the second component  200  in six planar orthogonal directions, such as the +/−x-direction, the +/−y-direction, and the +/−z-direction of an orthogonal coordinate system (see  FIG. 1 ), for example, which is herein referred to as six-way alignment, by averaging the elastic deformation of the respective elastically deformable alignment elements  202 ,  204 . 
     As depicted in  FIGS. 2 and 3 , the elastically averaged alignment system  10  includes an arrangement wherein the first component  100  has more than one of the first and second alignment features  102 ,  104 , and the second component  200  has more than one of the third and fourth elastically deformable alignment elements  202 ,  204 . The more than one of the third and fourth elastically deformable alignment elements  202 ,  204  are geometrically distributed with respect to respective ones of the more than one first and second alignment features  102 ,  104 , such that portions of the elastically deformable alignment elements of respective ones of the more than one third and fourth elastically deformable alignment elements  202 ,  204 , when engaged with respective ones of the more than one first and second alignment features  102 ,  104 , elastically deform to an elastically averaged final configuration that further aligns the first component  100  relative to the second component  200  in six planar orthogonal directions. 
     As depicted in  FIGS. 2 and 4 , the first alignment feature  102  is formed by a projection  106  having a curved cross section that extends off of a first wall  108 . In an embodiment, the curved cross section has a wave shape. As depicted in  FIG. 2 , the first wall  108  is on one side of a linear pocket  110  (individually herein referred to by reference numerals  110 . 1 ,  110 . 2  . . . ) formed in the first component  100 , and a second wall  112  opposing the first wall  108  is on an opposite side of the linear pocket  110 . The first alignment feature  102  is disposed extending sideways off of the first wall  108 , and the second alignment feature  104  forms a portion of the second wall  112 . 
     As depicted in  FIGS. 3, 5, 7A and 7B , the third elastically deformable alignment element  202  is formed by a curved projection  206  having a curved cross section that extends sideways off of a first side  208  of a third wall  210  (individually herein referred to by reference numerals  210 . 1 ,  210 . 2  . . . ). In an embodiment, the curved cross section has a crescent shape. 
     As also depicted in  FIGS. 3, 5, 7A and 7B , the fourth elastically deformable alignment element  204  is formed by a distal projection  212  that extends sideways off of a second side  214  of the third wall  210  at a distal end  216  of the third wall  210 . The second side  214  of the third wall  210  faces away from the first side  208  of the third wall  210 . In an embodiment, the third wall  210  has slots  218  on each side of the distal projection  212 , where the slots  218  are open at and extend from the distal end  216  of the third wall  210  toward a proximal end  220  of the third wall  210 . The portion of the third wall  210  between the slots  218  and having the distal projection  212  forms a cantilevered section of the third wall  210  that is capable of undergoing elastic deflection in a manner similar to how a cantilevered beam may be deflected at its free end. 
     In an embodiment, the first and second components  100 ,  200  are assembled together to arrive at the assembly depicted in  FIG. 1  as follows. First, the mating side  224  of the second component  200  (mating side depicted in  FIG. 3 ) is oriented proximate to and in face-to-face relationship with the mating side  116  of the first component (mating side depicted in  FIG. 2 ), but laterally offset such that an inner end  222  (see  FIG. 7A ) of the third wall  210  of the second component  200  is poised for entry into the open end  114  (see  FIG. 2 ) of the linear pocket  110  of the first component  100 . Then, the second component  200  is laterally and slideably engaged with the first component  100  such that the third and fourth elastically deformable alignment elements  202 ,  204  fully engage with respective ones of the first and second alignment features  102 ,  104 , as depicted in  FIGS. 6, 7A and 7B . A ramped surface  226  (see  FIG. 7B ) on the distal projection  212 , along with the curvatures of the first alignment feature  102  and third elastically deformable alignment element  202 , facilitates the assembly of the first and second components  100 ,  200 . As depicted in  FIGS. 6 and 7B , the first alignment feature  102  and the third elastically deformable alignment element  202  are disposed in an interference fit condition  302  in a first z-direction, and the second alignment feature  104  and the fourth elastically deformable alignment element  204  are disposed in an interference fit condition  304  in a second y-direction orthogonal to the first z-direction, when the first and second components  100 ,  200  are fully engaged with each other, thereby elastically aligning and restraining the first and second components  100 ,  200  in the +/−y and +/−z directions. While the engagement surfaces depicted in  FIGS. 6, 7A and 7B  are depicted overlapping each other to illustrate interference fit conditions  302 ,  304  (dotted lines depicting the degree of overlap), it will be appreciated that this is for illustration purposes only so as to illustrate an interference fit between the respective parts, and that in actuality the elastically deformable alignment elements  202 ,  204  will elastically deform by the amount of the interference fit condition shown. For example, the cantilevered crescent shaped end of the third elastically deformable alignment element  202  will tend to flatten out slightly and bend slightly at the cantilevered free end by the amount of the interference fit condition  302 , and the cantilevered distal projection  212  of the fourth elastically deformable alignment element  204  will tend to bend slightly at the cantilevered free end by the amount of the interference fit condition  304 . Elastic alignment and restraint of the first and second components  100 ,  200  in the +/−x-directions is achieved by the crescent shaped third elastically deformable alignment element  202  being elastically deformably nestled in a trough of the wave shaped first alignment feature  102 . 
     With reference now to  FIG. 8 , it can be seen that the first and second components  100 ,  200  are tightly fit relative to each other by the third elastically deformable alignment element  202  of the second component  200  being interferingly captured under the first alignment feature  102  of the first component  100 , which pulls the mating side  224  of the second component  200  snugly against the first wall  108 , and therefore snugly against the mating side  116 , of the first component  100 , with little or no gap therebetween. As depicted in  FIG. 8 , only an end portion of the crescent shaped cantilevered projection of the third elastically deformable alignment element  202  overlaps the wave shaped projection of the first alignment feature  102 , which provides for cantilevered elastic deflection of the third elastically deformable alignment element  202  when engaged with the first alignment feature  102 . 
     With reference now back to  FIGS. 2 and 3 , an embodiment includes an arrangement where there are two sets of the first and second alignment features  102 ,  104  (denoted by  102 . 1 ,  102 . 2 ,  104 . 1 ,  104 . 2 ) arranged in respective spaced-apart linear pockets  110 . 1 ,  110 . 2 , and two sets of the third and fourth elastically deformable alignment elements  202 ,  204  (denoted by  202 . 1 ,  202 . 2 ,  204 . 1 ,  204 . 2 ) arranged on respective spaced-apart linear walls  210 . 1 ,  210 . 2 . Like features and elements of the two sets are arranged so that any biasing forces they create between them oppose each other. For example, when elastically, deformably and matingly engaged with each other, the fourth elastically deformable alignment element  204 . 1  of the first set (toward the left in  FIG. 3 ) is elastically deformed inward thereby creating an outward biasing force on the second alignment feature  104 . 1  of the first set (toward the left in  FIG. 2 ), and the fourth elastically deformable alignment element  204 . 2  of the second set (toward the right in  FIG. 3 ) is elastically deformed inward thereby creating an outward biasing force on the second alignment feature  104 . 2  of the second set (toward the right in  FIG. 2 ), resulting in two outward biasing forces that oppose each other. The same result would be achieved if the placement of the first and second alignment features of the first and second sets, and the corresponding first and second elastically deformable alignment elements of the first and second sets, were switched. As such, the scope of the invention is not limited to only the orientation of features and elements depicted in  FIGS. 2 and 3 . 
     In view of all that is disclosed, illustrated, described, and incorporated by reference herein, it will be appreciated that the scope of the invention is not limited to only the use of the herein disclosed elastically deformable alignment elements and the corresponding alignment features, but also encompasses the use of such elements and features in combination with other elastic averaging alignment features, male or female. 
     When the first component  100  and second component  200  are components of a vehicle, an advantageous assembly results because the clamping force, together with the elastic deformation of the alignment features that has these parts in pressing contact already, reduces the tendency of the components to vibrate or rattle against one another, and thus improves the noise, vibration and harshness (NVH) characteristics of the components and the vehicle in which they are installed. The selective engagement of the elastically deformable alignment elements and the corresponding alignment features also provides a stiffened assembly of the first component  100  and second component  200  when the first and second components are mutually mated to each other, including a stiffness that is greater than that realized by using the alignment features alone, since the clamping force between the first component and second component increases the stiffness of the assembly, for example. In an embodiment, the first component  100  is a hinge portion of a fuel door for a vehicle, and the second component  200  is a cover portion of the fuel door. 
     While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the application.