Patent Application
20150016918
The subject invention relates to matable components and, more specifically, to elastically averaged matable components for alignment.
Some known components, in particular some vehicular components, which are to be mated together in a manufacturing process may be mutually located with respect to each other by alignment features that are oversized holes and undersized threaded bolts. Such alignment features are typically sized 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 such example includes the use of threaded bolts, which are received into corresponding female alignment features, typically apertures in the form of slots or holes. The components are formed with a predetermined clearance between the threaded bolts and their respective female alignment features to match anticipated size and positional variation tolerances of the alignment features that result from manufacturing (or fabrication) variances.
As a result, significant positional variation can occur between two mated components having the aforementioned alignment features, which may contribute to the presence of undesirably large variation in their alignment, particularly with regard to gaps and/or spacing therebetween. In the case where misaligned components are also part of another assembly, such misalignment may also affect the function and/or aesthetic appearance of the entire assembly (i.e., manufacturing stack-up). 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. Moreover, clearance between misaligned components may lead to relative motion therebetween, which may cause undesirable noise such as squeaking and rattling, and further result in the perception of poor quality.
In one aspect an elastically averaged alignment system is provided. The alignment system includes a first component comprising an inner wall defining an alignment aperture, a second component including a receiving aperture, and a fastener configured for insertion into the alignment aperture and the receiving aperture to couple the first and second components. The system further includes an elastically deformable collar inserted onto the fastener. The collar is configured to elastically deform against the inner wall to an elastically averaged final configuration upon insertion into the alignment aperture, thereby coupling the first and second components to facilitate aligning the first component and the second component in a desired orientation.
In another aspect a vehicle is provided. The vehicle includes a body and an elastically averaged alignment system integrally arranged within the body. The elastically averaged alignment system includes a first component including an inner wall defining an alignment aperture, a second component including a receiving aperture, and a fastener configured for insertion into the alignment aperture and the receiving aperture to couple the first and second component. The alignment system further includes an elastically deformable collar inserted onto the fastener. The collar is configured to elastically deform against the inner wall to an elastically averaged final configuration upon insertion into the alignment aperture, thereby coupling the first and second components to facilitate aligning the first component and the second component in a desired orientation
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 are applicable to vehicle body panels, but the alignment system disclosed herein 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 the 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. 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, 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 a four-way elastic averaging 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 or towed conveyance suitable for transporting a burden.
Described herein are alignment systems and methods for elastically averaged mating assemblies. The alignment systems include elastically deformable collars that are fitted to a fastener that is inserted into two or more components. The collar facilitates elastic averaging between components during fastener insertion, thereby resulting in proper alignment between the components.
In the exemplary embodiment, first component 100 includes an outer face 108 and an inner face 110 and is fabricated from a rigid material such as plastic. However, first component 100 may be fabricated from any suitable material that enables system 10 to function as described herein. In addition, inner face 110 may include one or more tabs or flanges (not shown) at least partially circumscribing alignment aperture 104 and extending outwardly from inner face 110 that are formed during a punching or a similar process used to form alignment aperture 104. In the exemplary embodiment, alignment aperture 104 has a generally circular cross-section. Alternatively, alignment aperture 104 may have any shape that enables system 10 to function as described herein. For example, alignment aperture 204 may be an elongated slot (e.g., similar to the shape of elastic tube alignment system described in co-pending U.S. patent application Ser. No. 13/187,675 and particularly illustrated in
While not being limited to any particular structure, first component 100 may be a decorative trim component of a vehicle with the customer-visible side being outer face 108, and second component 200 may be a supporting substructure that is part of, or is attached to, the vehicle and on which first component 100 is fixedly mounted in precise alignment.
In the exemplary embodiment, fastener 12 is a threaded bolt having a head portion 14, a threaded shank portion 16, and a centerline 18. Alternatively, fastener 12 may be any suitable fastener that enables system 10 to function as described herein. It is important to note that the diameter of shank portion 16 is smaller than the diameter or cross-section of alignment aperture 104. In known components, the threaded fastener is undersized and a component aperture is oversized to enable one component to move relative to the other to manually orient the components. Elastically deformable collar 20 may facilitate substantial alignment of centerlines 18, 106, and 206, as is described herein in more detail. However, centerlines 18, 106, and/or 206 may be slightly offset due to the elastic averaging over the entire system 10.
In the exemplary embodiment, and with further reference to
Elastically deformable collar aperture 32 is sized to receive threaded shank 16 through first end 24 such that fastener head portion 14 seats against first end 24. Alternatively, collar 20 may be formed integrally with fastener 12. Collar 20 and fastener 12 are then insertable into alignment aperture 104. Elastically deformable collar 20 is configured and disposed to interferingly, deformably, and matingly engage alignment aperture 104, as discussed herein in more detail, to precisely align first component 100 with second component 200 in two or four directions, such as the +/− x-direction and the +/− y-direction of an orthogonal coordinate system, for example, which is herein referred to as two-way and four-way alignment.
To provide an arrangement where elastically deformable collar 20 is configured and disposed to interferingly, deformably and matingly engage alignment aperture 104, the diameter or cross-section of alignment aperture 104 is less than the diameter or cross-section of collar body first end 24, which necessarily creates a purposeful interference fit between elastically deformable collar 20 and alignment aperture 104. As such, when inserted into alignment aperture 104, portions of the elastically deformable collar 20 elastically deform to an elastically averaged final configuration that substantially aligns fastener centerline 18, alignment aperture centerline 106, and receiving aperture centerline 206 in four planar orthogonal directions (the +/− x-direction and the +/− y-direction). Where alignment aperture 104 is an elongated slot (not shown), centerlines 18, 106 and 206 are aligned in two planar orthogonal directions (the +/− x-direction or the +/− y-direction). In the exemplary embodiment, a threaded nut 34 is threaded to threaded shank 16 after insertion of fastener 12 into alignment aperture 104 and receiving aperture 204. Threading of nut 34 onto shank 16 facilitates drawing collar 20 into alignment aperture 104 where it is elastically deformed and aligns and secures components 100 and 200 in a desired orientation. Alternatively, or in addition, receiving aperture 204 may be threaded and threaded shank 16 threads directly therein to facilitate drawing collar 20 into alignment aperture 104.
While
Biasing arms 64 define a generally tapered surface 82 having a first diameter d1 proximate second end 80 that is smaller than a second diameter d2 proximate first end 78. Aperture 72 is sized to receive threaded shank 16 such that fastener head portion 14 is seated against first surface 66. As collar 20 is inserted into alignment aperture 104 (as shown in
Additionally, as shown in
In view of the foregoing, and with reference to
Systems and methods for elastically averaged mating assemblies are described herein. The systems generally include a first component with an alignment aperture, a second component with a receiving aperture corresponding to the alignment aperture, a fastener, and an elastically deformable collar. The fastener is inserted into the collar and the two are inserted into the alignment aperture and receiving aperture. The collar elastically deforms against the walls of the alignment aperture to facilitate centering the fastener relative to the center of the alignment aperture to precisely mate the components in a desired orientation. Accordingly, the mating of the first and second components is elastically averaged over a corresponding pair or pairs of deformable collars and alignment apertures.
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.
