Patent Application
20150167717
The subject invention relates to the art of alignment and retention systems, more particularly to an elastically averaged alignment and retention system, and even more particularly to an elastically averaged alignment and retention system that also provides standoffs to the mating parts on which the alignment and retention system is incorporated.
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.
To align and secure components, the aforementioned male and female alignment features may be employed in combination with separate fastener components that serve to secure the components to each other. In such an assembly, the mating components are located relative to each other by the alignment features, and are fixed relative to each other by the separate fastener components. Use of separate alignment features and fastener components, one for alignment and the other for securement, may limit the effectiveness of each on a given assembly, as the alignment features cannot be employed where the fastener components are employed. Additionally, when the mating female alignment feature creates a through-hole in the associated mating component, neither surface of the associated mating component can be used as a show surface (A surface).
Accordingly, the art of alignment and retention systems can be enhanced by providing an alignment and retention system or mechanism that can ensure precise two-way or four-way alignment and retention of two components via elastic averaging of a single elastically deformable alignment and retention feature disposed in mating engagement with a corresponding single alignment element, and particularly where the mating female alignment feature can provide a show surface (A surface).
In one exemplary embodiment of the invention an elastically averaged alignment and retention system includes a first component having a first alignment member and an elastically deformable alignment and retention feature fixedly disposed with respect to the first alignment member, and a second component having a second alignment member and an alignment element fixedly disposed with respect to the second alignment member. The elastically deformable alignment and retention feature has an elastically deformable wall with an opening that defines an entry port, a distal end disposed at a distance from the first alignment member, a proximal end disposed proximate the first alignment member, and a retention portion disposed between the distal end and the proximal end. The alignment element has an alignment projection with a distal end disposed at a distance from the second alignment member, and a proximal end disposed proximate the second alignment member, the distal end of the alignment projection being larger than the proximal end of the alignment projection. The elastically deformable wall is configured and disposed to interferingly, deformably and matingly engage and retain the alignment projection, the distal end of the alignment projection being received by the entry port and retained by the retention portion of the elastically deformable wall. Portions of the elastically deformable wall when engaged with the alignment projection elastically deform to an elastically averaged final configuration that aligns the first component relative to the second component in at least two of four planar orthogonal directions.
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.
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:
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 and retention system may be used with any suitable components to provide elastic averaging for precision location, alignment and retention 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'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 Xmin, defined by Xmin=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. Publication No. U.S. 2013-0019455, 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 exemplary embodiment of the invention, and with reference to
In an embodiment, the EDAR feature 104 has an elastically deformable wall 106 having a distal end 108 disposed at a distance from the first alignment member 102 and defining an opening 110 that forms a distal end entry port (also herein referred to by reference numeral 110), a proximal end 112 disposed proximate the first alignment member 102, and a retention portion 114 disposed between the distal end 108 and the proximal end 112.
In an embodiment, the alignment element 204 is an alignment projection 206 having a distal end 208 disposed at a distance from the second alignment member 202, and a proximal end 212 disposed proximate the second alignment member 202, the distal end 208 of the alignment projection 206 being larger than the proximal end 212 of the alignment projection 206. In an embodiment, the distal end 208 of the alignment projection 206 has a spherical shape.
The elastically deformable wall 106 is configured and disposed to interferingly, deformably and matingly engage and retain the alignment projection 206, where the distal end 208 of the alignment projection 206 is received by the entry port 110 and retained by the retention portion 114 of the elastically deformable wall 106 when the first and second components 100, 200 are assembled together. Portions of the elastically deformable wall 106 when engaged with the alignment projection 206 elastically deform to an elastically averaged final configuration that aligns and retains the first alignment member 102 with the second alignment member 202, and the first component 100 relative to the second component 200, in at least two of four planar orthogonal directions, such as the +/−x-direction and/or the +/−y-direction of an orthogonal coordinate system, for example. Alignment and retention in two planar orthogonal directions is herein referred to as two-way alignment and retention, alignment and retention if four planar orthogonal directions is herein referred to as four-way alignment and retention. The elastically averaged alignment and retention system 10 may be configured as a two-way alignment and retention system or a four-way alignment and retention system. Additionally, the elastically averaged alignment and retention system 10 may be configured as a six-way alignment and retention system by further employing strategic interference in the z-direction between the alignment projection 206 and the elastically deformable wall 106, and between the alignment projection 206 and the first alignment member 102, which will be discussed in more detail below.
For discussion purposes, the mating side of the first alignment member 102 visible in
As previously mentioned, in some embodiments the first component 100 may have more than one EDAR feature 104, and the second component 200 may have more than one corresponding alignment element 204, depending on the requirements of a particular embodiment, where the plurality of EDAR features 104 are geometrically distributed in coordinated relationship to a geometrical distribution of the plurality of alignment elements 204 such that each alignment element 204 is receivable into a respective EDAR feature 204, as illustrated in
In an embodiment, the elastically deformable wall 106 has a conical shape that transitions from narrow at the distal end 108 to broad at the proximal end 112 to form an undercut shape that defines an interior space 116 of the retention portion 114 (best seen with reference to
Reference is now made to
At the pre-assembly stage, as depicted in
At the partially assembled stage, as depicted in
At the assembled stage, as depicted in
As depicted in
In an embodiment, it may not be necessary for the side 11 of the first component 100 to be visibly acceptable by the end-user, which is referred to as a “B” side. As such, and with reference now to
While embodiments of the distal end 208 of the alignment projection 206 have been herein described and illustrated having a spherical shape (see
In the assembled state, see
As previously mentioned, in some embodiments the first component 100 may have more than one EDAR feature 104, and the second component 200 may have more than one corresponding alignment element 204. For example, and with reference back to
With reference still to
Alternatively, and with reference now to
While
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 EDAR features 104 and corresponding alignment elements 204, but also encompasses the use of EDAR features 104 and corresponding alignment elements 204 in combination with other elastic averaging alignment features, male or female.
In view of all of the foregoing, and with reference now to
When the first component 100 and second component 200 are components of a vehicle, an advantageous assembly results because the retaining 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 EDAR feature 104 and the alignment element 204 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 retaining force between the first component and second component increases the stiffness of the assembly, for example.
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.
