Patent Application
20080202674
The present invention is predicated upon the provision of a system and method for reinforcement of a structural member, which may include attachment features for placement of an activatable material onto a carrier and/or attachment of the system to a structural member.
For many years industry, and particularly the transportation industry has been concerned with providing functional attributes sealing, baffling, acoustic attenuation, sound dampening and reinforcement to articles of manufacture such as automotive vehicles. In turn, industry has developed a wide variety of materials and parts for providing such functional attributes. In the interest on continuing such innovation, the present invention seeks to provide an improved material and/or improved part for providing such functional attributes. The material and/or part can provide sealing, baffling, acoustic attenuation, sound dampening, combinations thereof or the like, but the part and/or material have been found to be particularly adept at providing reinforcement.
The present invention provides systems and methods for improving structural frame members of transportation vehicles or otherwise.
In one aspect, the present invention provides a reinforcement system for a structural member. The system includes an integrally formed carrier member extending between a first and second end, the carrier member forming a plurality of cavities extending between the first and second end of the carrier. The system further includes an activatable material attached to the carrier and one or more fasteners for attachment of the carrier to an interior portion of a structural member.
In one aspect, the present invention provides a reinforcement system for a structural member. The system includes a carrier member having a length extending along an axis between a first end and a second end. The carrier member includes one or more sidewalls joined together to form one or more cavities extending along the axis, wherein the carrier includes a cross-sectional shape roughly corresponding to the cross-sectional shape of interior walls of a hollow structural member. The system also includes activatable material placed over the carrier, the activatable material configured to expand upon application of heat and adhere to the interior walls of the hollow structural member to provide reinforcement for the same. The system further includes one or more attachment features located on or integrated with the carrier member or activatable material for attaching the activatable material to the carrier and an additional one or more attachment features for attaching the carrier member to the interior walls of the hollow structural member, the one or more attachment features comprising fasteners located on the one or more sidewalls.
In one aspect, the present invention provides a method of reinforcing a structural member. The method includes the steps of: i) extruding a carrier member having a plurality of cavities extending along a length of the carrier; ii) attaching an activatable material to the carrier with one or more fasteners; and iii) attaching the carrier to an interior portion of a structural member.
It should be appreciated that the above referenced aspects and examples are non-limiting as other exists with the present invention as shown and described herein. Still further, it should be appreciated that the above referenced aspects and examples of the invention may be combined to form other unique configurations, as demonstrated in the drawings, or otherwise.
The present invention is predicated upon a system and method of reinforcing a structural member, particularly an automotive frame or frame rail member. In doing so, the present invention contemplates a carrier having an activatable material place thereover, which is configured for placement within a hollow structural member. Subsequently, the activatable material is activated causing the carrier to attach to the structural member and provide reinforcement thereto.
In one aspect, by example referring to
In yet another aspect, by example referring to
It should be appreciated that the above referenced examples are not limiting as other examples of these aspects are shown throughout the drawings and the skilled artisan will be able to contemplate other configurations that will remain within the scope of the present invention. Also, it should be appreciated that other features can be part of or can be employed in conjunction with the present invention such feature shown and described herein or elsewhere. Still further, it should be appreciated that the above referenced aspects of the invention may be combined to form other unique configurations, as demonstrated in the drawings, or otherwise.
The reinforcing system of the present invention includes a carrier adapted for placement within a hollow cavity of a structural member. The carrier is preferably configured to extend along an axis and more preferably along a length of the structural member. The carrier includes at least a first end and a second end which reside on opposite ends of an axis of the carrier. The carrier may also include one or more hollow cavities which extend along the length or axis of the carrier. The carrier can be straight or contoured along its length.
The carrier is formed of one or more walls that extend along the length of the carrier, which may be joined or otherwise integrated together. The carrier may have separate walls joined together by attachments such as adhesives or fasteners or the carrier may be integrally formed (e.g. molded) as a substantially unitary structure. Optionally, it is contemplated that the one or more of the walls may be internal walls located substantially within exterior walls of the carrier. Preferably, upon joining of the walls, the carrier forms one or more (or a plurality) of cavities (e.g., 1, 2, 3, 4, 5, 6 or more cavities) that extends along at least a portion of the length of the carrier and preferably substantially the entire length of the carrier. It is contemplated that the one or more cavities may form openings extending through the carrier between the first and second end of the carrier.
In one configuration, referring to
It is contemplated that one or more of the walls 22 of the carrier 12 may be located adjacent an interior wall 28 of the structural member 14 in which it is placed. For example, referring to
Optionally, the carrier may include one or more through holes 30 formed in the walls of the carrier. The through holes may provide reduced weight of the carrier. The through holes may also be used to control any flow of the activatable material, or otherwise. Still further, the through holes may be used to engage any of the attachment features, or otherwise, as described herein, for attachment of the carrier to the structural member, or attachment of other components (e.g., activatable material or otherwise) to the carrier, also as described herein.
The carrier may be formed of a variety of materials and can be formed of a single material or multiple materials. As examples, the carrier may be formed of polymeric materials, metals (e.g., aluminum, steel, magnesium, metal alloys) combinations thereof or the like. Exemplary, polymeric materials (e.g., thermoplastics, rubber, elastomer, thermosets or the like), include, without limitation, polyester, polypropylene, polyamide, molding compounds (e.g., sheet or bulk molding compound), polyethylene, polyvinylchloride, combinations thereof or the like. As will be recognized, the technique for forming and shaping the carrier will typically depend upon the material of the carrier. Examples of techniques include, without limitation, molding, stamping, hydroforming or the like. Thus, the carrier could be a metal stamping, a metal casting (e.g., a metal, aluminum, aluminum foam, magnesium or magnesium foam casting), a thixomolded structure. The carrier could also be a molded (e.g., injection, compression or blow molded) plastic structure. Furthermore, it is contemplated that the carrier maybe formed through an extrusion process. Other forming methods are contemplated.
Preferably, the system 10 includes an activatable material 18 configured for providing structural reinforcement properties upon activation and curing thereof. In one configuration, the carrier includes activatable material located over the carrier. In one preferred configuration, the activatable material comprises an adhesive material, or otherwise includes adhesive qualities, for bonding to the carrier and structural member upon activation.
The activatable material may be placed and/or attached to the carrier using attachment techniques such as adhesion, fasteners or otherwise. However, in one preferred configuration, the carrier member and/or components associated with the carrier member attach the activatable material to the carrier. As previously mentioned, the attachment features may be integrally formed with, or otherwise attached, to the carrier, activatable material, or both.
The activatable material may be an expandable or foamable material that is activated to expand and then cure to form a strong bond between adjacent surfaces (e.g. attachment surfaces). When expandable, the adhesion material typically undergoes a volumetric expansion of no greater than 500%, more typically no greater than 300% and even more typically no greater than 150% over its original non-expanded volume. Of course, higher expansion levels are also contemplated within the present invention. The activatable material may also be a non-expandable adhesive material, which may or may not be heat activated.
In one embodiment, the activatable material is formed of a high compressive strength heat activated reinforcement material having foamable characteristics. The material may be generally dry to the touch or tacky and can be placed upon surfaces of members in any form of desired pattern, placement, or thickness, but is preferably a substantially uniform thickness. One exemplary expandable material is L-5204 structural foam available through L&L Products, Inc. of Romeo, Mich. Preferably the strength (e.g., tensile strength) of the adhesive material is at least about 5 Mpa, more preferably at least about 12 Mpa and even more preferably at least about 20 Mpa, although the strength may be lower as well.
Though other heat activated materials are possible for the activatable material, a preferred heat activated material is an expandable plastic, and preferably one that is foamable. A particularly preferred material is an epoxy-based structural foam. For example, without limitation, the structural foam may be an epoxy-based material, including an ethylene copolymer or terpolymer that may possess an alpha-olefin. As a copolymer or terpolymer, the polymer is composed of two or three different monomers, i.e., small molecules with high chemical reactivity that are capable of linking up with similar molecules.
A number of epoxy-based structural foams are known in the art and may also be used to produce the structural foam adhesive material. A typical structural foam includes a polymeric base material, such as an epoxy resin or ethylene-based polymer which, when compounded with appropriate ingredients (typically a blowing and curing agent), expands and cures in a reliable and predicable manner upon the application of heat or the occurrence of a particular ambient condition. From a chemical standpoint for a thermally-activated material, the structural foam is usually initially processed as a flowable thermoplastic material before curing. It will cross-link upon curing, which makes the material incapable of further flow. An example of a preferred structural foam formulation for the adhesive material is an epoxy-based material that is commercially available from L&L Products of Romeo, Mich., under the designations L5206, L5207, L5208, L5209, L-5220, L-7102, L-7220, XP321 and XP721 or others.
One advantage of the preferred activatable materials over prior art materials is that the preferred materials can be processed in several ways. The preferred materials can be processed by injection molding, extrusion compression molding or with a mini-applicator. This enables the formation and creation of part designs that exceed the capability of most prior art materials. In one preferred embodiment, the structural foam (in its uncured state) generally is dry or relatively free of tack to the touch. Moreover, the activatable materials may be applied to the attachment surfaces of the members and/or connectors before or after assembly of those components together.
While the preferred materials for fabricating the activatable material have been disclosed, the materials can be formed of other materials as well. Such material can be heat-activated or otherwise activated by an ambient condition (e.g. moisture, pressure, time or the like) and cures in a predictable and reliable manner under appropriate conditions for the selected application. One such material is the epoxy based resin disclosed in U.S. Pat. No. 6,131,897, the teachings of which are incorporated herein by reference, filed with the United States Patent and Trademark Office on Mar. 8, 1999 by the assignee of this application. Some other possible materials include, but are not limited to, polyolefin materials, copolymers and terpolymers with at least one monomer type an alpha-olefin, phenol/formaldehyde materials, phenoxy materials, and polyurethane materials with high glass transition temperatures. See also, U.S. Pat. Nos. 5,766,719; 5,755,486; 5,575,526; and 5,932,680, (incorporated by reference). In general, the desired characteristics of the structural foam include relatively high stiffness, high strength, high glass transition temperature (typically greater than 70 degrees Celsius), and good corrosion resistance properties. In this manner, the material does not generally interfere with the materials systems employed by automobile manufacturers.
In applications where the activatable material is a heat activated, thermally expanding material, an important consideration involved with the selection and formulation of the material is the temperature at which a material reaction, expansion, activation, flow and possibly curing, will take place. For instance, in most applications, it is undesirable for the material to be reactive at room temperature or otherwise at the ambient temperature in a production line environment. More typically, the material becomes reactive at higher processing temperatures, such as those encountered in an automobile assembly plant, when the material is processed along with the automobile components at elevated temperatures or at higher applied energy levels, e.g., during painting preparation steps. While temperatures encountered in an automobile assembly operation may be in the range of about 148.89° C. to 204.44° C. (about 300° F. to 400° F.), body and paint shop applications are commonly about 93.33° C. (about 200° F.) or slightly higher. If needed, blowing agent activators can be incorporated into the composition to cause expansion at different temperatures outside the above ranges.
Generally, suitable materials have a range of expansion ranging from approximately 0 to over 1000 percent. The level of expansion of the materials may be increased to as high as 1500 percent or more. Typically, strength is obtained from products that possess low expansion.
Some other possible materials for use as the activatable material include, but are not limited to, polyolefin materials, copolymers and terpolymers with at least one monomer type an alpha-olefin, phenol/formaldehyde materials, phenoxy materials, and polyurethane. See also, U.S. Pat. Nos. 5,266,133; 5,766,719; 5,755,486; 5,575,526; 5,932,680; and WO 00/27920 (PCT/US 99/24795) (all of which are expressly incorporated by reference).
In another embodiment, the material may be provided in an encapsulated or partially encapsulated form, which may comprise a pellet, which includes an expandable foamable material, encapsulated or partially encapsulated in an adhesive shell. An example of one such system is disclosed in commonly owned, co-pending U.S. application Ser. No. 09/524,298 (“Expandable Pre-Formed Plug”), hereby incorporated by reference.
In addition, as discussed previously, preformed patterns may also be employed such as those made by extruding a sheet (having a flat or contoured surface) and then die cutting it according to a predetermined configuration in accordance with the chosen structure, panel or beam, and applying it thereto.
The activatable material 18 is attached or otherwise placed adjacent an exterior portion of the carrier 12. Preferably, the activatable material remains proximate to the carrier during placement within the structural member 14 or otherwise. The activatable material, carrier or both may include an attachment feature for attachment of the activatable material to the carrier. Optionally, the activatable material may also be placed on or with other components attached or otherwise associated with the carrier such as attachment or fastening devices (e.g. end caps), or otherwise.
In a first configuration, referring to
Referring to
In one specific example, referring to
In another specific example, referring to
In another specific example, referring to
In another specific example, referring to
In yet another specific example, referring to
In still another example, one or more of the attachment components or otherwise may be staked (e.g. heat or cold) to cause attachment of the activatable material to the carrier member. This may be achieved through deformation of one or more of the attachment components, or otherwise. In one application, heat staking may be used to cause an application of pressure and heat to plastically deform an attachment component to engage another attachment component. Alternatively, cold staking may be used to cause an application of pressure against a heated attachment component to plastically deform the same and cause it to engage another attachment component. Further, hot air may be used to cause deformation of one or more of the attachment components for deformation and engagement of the same. Still further, a heat activatable material, such as an adhesive or otherwise, may be applied between the activatable material and carrier, or may be formed therewith or applied thereto, wherein upon an application of heat, via heated air, hot press or otherwise, the activatable material and carrier become attached. In this configuration the heat activatable adhesive may have an activation level lower than the activation level of the activatable material being attached to the carrier. Also, in still another application, the carrier may be heated, via hot air or otherwise, to cause plastic deformation of the activatable material in order to engage the same. Other configurations are available to cause plastic deformation and/or attachment of the activatable material to the carrier.
In view of the foregoing, Referring to
In another configuration, referring to
It should be appreciated that any that the above examples or features may be combined to form additional embodiments. Also, it should be appreciated that other configurations are available.
Optionally, the carrier may include one or more additional attachment features for mounting the carrier to a structural member and more particularly to an interior walls forming the hollow cavity of the structural member. Such attachment features may be integrally formed with the carrier or comprise a separate attachment feature which is attached to the carrier and configured for matingly engaging with the structural member. Suitable attachment features include mechanical fasteners (e.g. threaded fasteners, hook and latch, snap fittings, Christmas tree clips, or otherwise). Other fasteners include non-mechanical fasteners (e.g. friction fittings, adhesives, or otherwise).
The fasteners may be formed or placed about portions of the carrier to attach the same to a structural member. However, preferably, at least one attachment feature is located at the first end of the carrier and at least one end is located at the second end of the carrier. Thus it is possible to generally orientate the axis of the carrier with the axis of the structural cavity.
By example, referring to
The reinforcing system of the present invention may be used in a variety of applications which includes a structural member and which may benefit from reinforcement thereof. In one particular application, the system may be used in the vehicular industry for reinforcing structural systems thereof to form a reinforced structural member. In doing so, any of the systems herein can be placed in a structural member and activated to form the reinforced structural member.
For example, it is contemplated that the system may be used to reinforce various structural members of a vehicle including frame, frame rails, rockers, pillars, roof members, or otherwise. The structural member may comprise one or more frame components (such as tubular frame members or otherwise) extending the length of a vehicle and/or other frame members located therebetween (e.g. rocker frame members). In one particularly advantageous application, the system may be used to reinforce a frame rail, rocker, or the like depending on the type of frame (e.g. unibody, etc.).
Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. Plural structural components can be provided by a single integrated structure. Alternatively, a single integrated structure might be divided into separate plural components. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention.
The preferred embodiment of the present invention has been disclosed. A person of ordinary skill in the art would realize however, that certain modifications would come within the teachings of this invention. Therefore, the following claims should be studied to determine the true scope and content of the invention.
