Patent Description:
The present invention in general relates to vehicle body components and in particular to vehicle body components with sections formed of different fiber reinforced composites.

Weight savings in the automotive, transportation, aerospace, and logistics based industries has been a major focus in order to make more fuel-efficient vehicles both for ground and air transport. In order to achieve these weight savings, light weight composite materials have been introduced to take the place of metal structural and surface body components and panels. Composite materials are materials made from two or more constituent materials with significantly different physical or chemical properties, that when combined, produce a material with characteristics different from the individual components. The individual components remain separate and distinct within the finished structure. A composite material may be preferred for reasons that include materials which are stronger, lighter, or less expensive when compared to traditional materials. Still another advantage over metals is reduced corrosion, leading to longer operational life and reduced maintenance costs.

There are two categories of constituent materials: matrix and reinforcement. At least one portion of each type is required. The matrix material surrounds and supports the reinforcement materials by maintaining their relative positions. The reinforcements impart their special mechanical and physical properties to enhance the matrix properties. A synergism produces material properties unavailable from the individual constituent materials, while the wide variety of matrix and strengthening materials allows the designer of the product or structure to choose an optimum combination.

The use of fiber inclusions to strengthen a matrix is well known to the art. Well established mechanisms for the strengthening of a matrix include slowing and elongating the path of crack propagation through the matrix, as well as energy distribution associated with pulling a fiber free from the surrounding matrix material. In the context of sheet molding composition (SMC) formulations, bulk molding composition (BMC) formulations, and resin transfer molding (RTM) fiber strengthening has traditionally involved usage of chopped glass fibers.

Structural automotive components are designed to protect vehicle occupants during collisions by absorbing and dissipating kinetic energy. For example, as shown in <FIG>, front passenger vehicle doors <NUM> and back passenger vehicle doors <NUM> commonly include side impact bars <NUM>, <NUM>, also known as an anti-intrusion bars or beams, which are designed to protect passengers from side impacts. Another example is shown in <CIT>, which shows a similar side door having two beams attached to the body at different outward distances from the centre of the door. Side impacts are particularly dangerous since the location of impact is very close to the passenger, who can be immediately reached by the impacting vehicle or object. The role of the side impact bar is to absorb the kinetic energy of the colliding vehicles or objects that is partially converted into internal work of the members involved in the crash. Structural automotive components are also designed to minimize damage to the vehicle in low speed collisions by absorbing the kinetic energy by temporally deforming or deflecting.

Over time, geometries, overall configurations, and materials of structural vehicle components have changed in an to attempt to reduce vehicle weight. For example, <FIG> shows a structural vehicle component <NUM> having an upper beam <NUM> and a lower beam <NUM> made of composite materials. While this proved a successful use of composites, this design mimics the use of metal components and does not fully leverage the benefits available from composite components.

Thus, there exists a need for a vehicle structural component design that utilizes composite materials to lower the weight of the component, while improving the safety performance and manufacturability compared to conventional vehicle components.

The present invention provides a vehicle component according to claim <NUM> that includes a body, a first beam, and a second beam. The body has a first fixture region and a second fixture region. The first beam is formed of a first composite material and has a first beam shape. The first composite material is for example thermoset resin, which may or may not be reinforced with chopped fibers such as carbon fibers, glass fibers, aramid fiber, natural fibers, cellulosic fibers, or a combination thereof. The first beam is attached to the body and extends between the first fixture region and the second fixture region of the body. The second beam is formed of a second composite material and has a second beam shape that is simple compared to the first beam shape. The second composite material is for example a unidirectional fiber reinforced composite, in which the fibers may be carbon fibers, glass fibers, aramid fiber, natural fibers, cellulosic fibers, of a combination thereof. The second beam is attached to the body and extends between the first fixture region and the second fixture region of the body. The first beam is spaced apart from said second beam on the body. The outer surface of the first beam extends outward from a center line relative to the outer surface of the second beam. The first beam has a first surface area and the second beam has a second surface area, a ratio of the first surface area to the second surface area being between <NUM>-<NUM>:<NUM>.

The present invention is further detailed with respect to the following drawings that are intended to show certain aspects of the present invention but should not be construed as a limit on the practice of the present invention.

The present invention has utility as a lightweight vehicle structural component providing improved automotive crash resistance by strengthening vehicle body components while reducing weight. Accordingly, vehicle structural components according to embodiments of the present disclosure have improved safety performance and manufacturability and reduced weight compared to existing vehicle structural components. While the present invention is discussed in the context of vehicle door due the rigorous safety standards associated with a door, it is appreciated that the present invention is suited for the production of a variety of vehicle components that also illustratively include hoods, decklids, roofs, tailgates, and liftgates.

The present invention will now be described with reference to the following embodiments. As is apparent by these descriptions, this invention can be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. For example, features illustrated with respect to one embodiment can be incorporated into other embodiments, and features illustrated with respect to a particular embodiment may be deleted from the embodiment. In addition, numerous variations and additions to the embodiments suggested herein will be apparent to those skilled in the art in light of the instant disclosure, which do not depart from the instant invention. Hence, the following specification is intended to illustrate some particular embodiments of the invention, and not to exhaustively specify all permutations, combinations, and variations thereof.

It is to be understood that in instances where a range of values are provided that the range is intended to encompass not only the end point values of the range but also intermediate values of the range as explicitly being included within the range and varying by the last significant figure of the range. By way of example, a recited range of from <NUM> to <NUM> is intended to include <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>.

The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Unless indicated otherwise, explicitly or by context, the following terms are used herein as set forth below.

As used in the description of the invention and the appended claims, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Also as used herein, "and/or" refers to and encompasses any and all possible combinations of one or more of the associated listed items, as well as the lack of combinations when interpreted in the alternative ("or").

As used herein, the term "side impact pole test" refers to NCAP Side Impact Rigid Pole Test as defined by US Department of Transportation Rev. <NUM>/<NUM>/<NUM>.

As used herein, the term "continuous fiber" refers to fibers that extend from edge to edge of a vehicle component, or fibers that are placed in a pattern within the vehicle component without having been cut.

As shown in <FIG>, embodiments of a vehicle component <NUM> of the present invention include a body <NUM> having a first fixture region <NUM> and a second fixture region <NUM>, a first beam <NUM>, and a second beam <NUM>. The body <NUM> and beams <NUM>, <NUM> each have a predetermined geometry based on a given application and intended location within a vehicle so as to be complementary to other components of the vehicle. It is appreciated that the first fixture region <NUM> and a second fixture region <NUM> are formed integral from the same material as the body <NUM>, or alternatively are each independently inserts to the body having a different composition from the remainder of the body <NUM>.

The body <NUM> is limited in construction and materials only by compatibility with the beams <NUM> and <NUM>, and is illustratively formed of steel, aluminum, magnesium alloys, titanium, titanium alloys, fiberglass set up sheets embedded in thermoset resin, SMC, BMC, or a combination thereof. In certain inventive embodiments, the body <NUM>, the first fixture region <NUM>, and the second fixture region <NUM> are formed of SMC and other materials. The body <NUM> has an inner side <NUM> and an outer side relative to vehicle passenger compartment. In still other embodiments, the first fixture region <NUM>, and the second fixture region <NUM> are integral with the body <NUM>. It is noted that joints are conventionally formed based on the nature of the material with adhesives, mechanical fasteners, or a combination thereof generically, while welding and brazing are most often used to form a body <NUM> from metals. An exemplary joining of the first beam <NUM> between the second fixture region <NUM> and the first fixture region <NUM> is shown in <FIG>, respectively using a combination of mechanical fasteners <NUM> and adhesive <NUM>. An exemplary joining of the second beam <NUM> between the second fixture region <NUM> and the first fixture region <NUM> is also shown in <FIG>, respectively using a combination of mechanical fasteners and adhesive. It is further appreciated that the body <NUM> includes hardened points for mounting hinges <NUM>, in <FIG> on a front stile and a rear stile lock (not shown for visual clarity) to selectively allow the component <NUM> to secure to the remainder to the vehicle. While it is conventional that a component <NUM> that forms a vehicle door has two front hinges and a lock-vehicle chassis post engagement to form a three point closure, it should be appreciated that this is only exemplary and other types of components <NUM> and indeed, other types of doors have different hardware for selectively moving the component relative to the vehicle.

The first beam <NUM> is attached to the body <NUM>, generally at the first fixture region <NUM> and second fixture region <NUM>, such that the first beam <NUM> spans between the first fixture region <NUM> and second fixture region <NUM> of the body <NUM>. The first beam <NUM> is formed from chopped fiber reinforced resin and is characterized by a complex shape positioned such that to the extent there is concavity, the opening is directed away from the expected direction of impact. The first beam <NUM> is formed from a variety of resins. These illustratively include SMC, epoxy, acrylonitrile butadiene styrene (ABS), polycarbonate, or random-oriented fiber reinforced thermoplastic resin (FRTP). When an inventive component <NUM> is a door, the expected direction of impact is from the door exterior. Fiber fillers operative herein illustratively include carbon fibers, glass fibers, aramid fibers, cellulosic fibers, or a combination thereof. In some inventive embodiments, the chopped fiber is glass fiber, alone or in combination with other types of fiber. It is appreciated that in some inventive embodiments, a minority by fiber weight in the first beam <NUM> is continuous fiber. Exemplary continuous fibers are detailed below with respect to the second beam <NUM>. A typical thickness of the first beam <NUM> at a given point ranges from <NUM> to <NUM> when the first beam is carbon fiber-SMC(CF-SMC). In still other embodiments, the thickness of the first beam <NUM> is from <NUM> to <NUM> when the first beam is CF-SMC.

In some inventive embodiments, the first beam is reinforced with a rib <NUM> of a same material as the first composite material to impart additional strength or penetration resistance to the first beam <NUM>. The rib <NUM>, if present, can be adhered to the exterior of the first beam <NUM> or the first beam <NUM> molded so as encase the rib <NUM>. It is appreciated that the first beam <NUM> is readily formed from uniform thickness resin molding or can vary in thickness across the extent thereof. According to some inventive embodiments, the first beam <NUM> has surface treatments <NUM> illustratively includes grooves, ridges, dimples, or a combination thereof that are known to contribute additional strength thereto.

The second beam <NUM> is attached to the body <NUM>, generally at the first fixture region <NUM> and second fixture region <NUM>, such that second beam <NUM> spans between the first fixture region <NUM> and second fixture region <NUM> of the body <NUM>. The second beam <NUM> is formed of a second composite material that is different from the first composite material of the first beam <NUM>. In particular, the second beam <NUM> is formed of a continuous fiber reinforced composite, with the majority of fiber direction chosen to be orthogonal to an expected direction of impact. It is appreciated that lesser amounts of the total fiber content in the second beam <NUM> can have a different orientation relative the majority of the continuous fiber direction. In other inventive embodiments continuous fiber extend in multiple directions such that no single direction includes a majority by weight of the fiber; for example, as several vehicle components other than doors. The continuous fiber reinforced composite includes metal wires, carbon fibers, glass fibers, aramid fibers, or a combination thereof impregnated with a resin to define the shape of the second beam <NUM>. In some inventive embodiments, the continuous fiber is only carbon fiber as owing to the attractive strength and weight attributes of carbon fiber. An exemplary source of carbon fiber operative herein is Tenax® (Teijin Ltd. In some inventive embodiments, a lesser amount by weight of any of the aforementioned chopped fiber is also present in the second beam <NUM> relative to the amount by weight of continuous fiber. A typical thickness of the second beam <NUM> at a given point ranges from <NUM>-<NUM>. In still other inventive embodiments, the thickness of the second beam rages from <NUM> to <NUM>. The second beam <NUM> is formed from a variety of resins. These illustratively include thermoset resins such as SMC, epoxy, vinyl ester, phenol, thermosetting polyimide, polyurethane, urea, melamine and bismaleimide; and thermoplastics such as polyamide, polyalkylenes, ABS, polycarbontes, FRTP, poly (methyl methacrylate) (PMMA). In addition to a single epoxy resin, a copolymer of an epoxy resin and a thermosetting resin, a modified product, a resin obtained by blending two or more kinds of resins, and so on can be used. In some inventive embodiments, the second beam <NUM> is formed with a "top hat" characterized by edges parallel to a central section with orthogonal sides intermediate between the edges and the central section. In still other embodiments, the second beam <NUM> is formed with a rectilinear box cross section. It is appreciated that the second beam <NUM> is formed with still other cross-sectional shapes, as measured in the middle of the beam <NUM>; these other cross-sectional shapes including triangular, pentagonal, and hexagonal. According to some inventive embodiments, the second beam <NUM> has surface treatments <NUM> illustratively includes grooves, ridges, dimples, or a combination thereof that are known to contribute additional strength thereto. In some inventive embodiments, the second beam <NUM> is reinforced with a rib <NUM> of a same material as the second composite material to impart additional strength or penetration resistant to the first beam <NUM>. The rib <NUM>, if present, can be adhered to the exterior of the second beam <NUM> or the second beam <NUM> molded so as encase the rib <NUM>.

The relationship between the first beam <NUM> and the second beam <NUM> is critical to providing a lightweight component that retains a high degree of crush resistance. The first beam <NUM> is generally designed to include a complex shape relative to the second beam <NUM>. In some inventive embodiments, the first beam <NUM> is designed to have a greater tensile stiffness per unit area than the second beam <NUM> orthogonal to the first beam and the second beam, while the second beam <NUM> is designed to have a greater strength per unit area than the first beam <NUM> orthogonal to the first beam and the second beam; while in other inventive embodiments one or both of these attributes are not present. With respect to the body being a door as shown in the drawings, the first beam <NUM> has a complicated shape that is readily molded with SMC that can form a mount for a window frame, a door mirror, or a combination thereof. In some inventive embodiments, the surface area of the first beam <NUM> has a ratio to the surface area of the second beam <NUM> of between <NUM>-<NUM>:<NUM>. This feature is best shown by way of comparison between the inventive vehicle component <NUM> of <FIG> and an existing vehicle component <NUM> of <FIG>.

While the first beam <NUM> is shown mounted above and spaced apart from the second beam <NUM> in the drawings, it is appreciated that the relative position of the beams <NUM> and <NUM> is varied depending on the nature of the vehicle component. In still other embodiments, additional beams formed of the materials of the first beam <NUM> or the second beam <NUM> are present to impart desired properties to a given vehicle component <NUM>. By way of example, another beam of the composition of the first beam <NUM> could be attached along a lower edge of a vehicle component, another beam of the composition of the second beam <NUM> could be attached proximal to the second beam <NUM> to impart additional stiffness, or both types of beams are replicated in a given vehicle component. It is also appreciated that while the first beam <NUM> and second beam <NUM> are shown generally parallel to one another to provide excellent response to a side pole crash test, beams according to the present invention are readily deployed at a variety of relative angles.

To further facilitate protection relative to an exterior impact, the first beam <NUM> in some embodiments is displaced outward on the vehicle component <NUM> relative to the second beam <NUM>. As best shown in <FIG>, an outer surface <NUM> of the first beam <NUM> is outwardly displaced relative to an outer surface <NUM> of the second beam <NUM>. More specifically, the outer surface <NUM> of the first beam <NUM> is positioned a first distance D1 from a central axis A of the body <NUM>, and the outer surface <NUM> of the second beam <NUM> is positioned a second distance D2 from the center line A of the body <NUM>, wherein the first distance D1 is greater than the second distance D2. Accordingly, in an impact event, the first beam <NUM> contacts an impacting object before the second beam <NUM>. Without intending to be bound to a particular theory, the first beam <NUM>, for example, formed of chopped fiber reinforced SMC having a high impact energy absorption capability, absorbs and dissipates the kinetic energy of the impact, preventing penetration into the vehicle passenger compartment, while the second beam <NUM>, generally formed of a unidirectional fiber reinforced composite having a high stiffness, provides necessary rigidity to hold the various components of the vehicle component <NUM> intact and transmit impact forces to the body <NUM> of the vehicle component.

As best shown in <FIG>, according to certain inventive embodiments, the first fixture region <NUM> defining a front stile of the door is configured to receive at least one hinge <NUM> to secure the vehicle component <NUM> to a frame of a vehicle <NUM>, while the second fixture region <NUM> defining the rear stile of the door is configured to receive a latch <NUM> to releasably secure the vehicle component <NUM> to the vehicle frame <NUM>. According to some inventive embodiments and as best shown in <FIG> and <FIG>, the vehicle component <NUM> includes one or both of a first reinforcing component <NUM> attached to the body <NUM> at the first fixture region <NUM> and a second reinforcing component <NUM> attached to the body <NUM> at the second fixture region <NUM>.

As shown in <FIG>, the vehicle component <NUM> may be an inner structure for reinforcing a vehicle door or other vehicle body component. According to embodiments, the vehicle component <NUM> is connected to an outer skin <NUM> on an outer side <NUM> of the body <NUM>. In further embodiments, the vehicle component <NUM> is placed between an outer skin <NUM> on an outer side <NUM> of the body <NUM> and an inner skin <NUM> on an inner side <NUM> of the body <NUM>. According to embodiments, the outer skin <NUM> is an outer body panel formed of at least one of steel, aluminum, and a composite material. The inner skin <NUM> is an aesthetic panel facing the vehicle interior. According to embodiments, the vehicle component <NUM> further comprising at least one of sound deadening material, vehicle electronics, an aramid panel, and HVAC components positioned in a cavity defined between the body <NUM> and at least one of the outer skin <NUM> and the inner skin <NUM>.

The present invention is further detailed with respect to the following nonlimiting example.

A vehicle door is constructed and skinned according to <FIG> with a chopped carbon fiber filled first beam and a glass fiber based unidirectional fiber second beam. The resulting door represents a <NUM>% weight savings relative to a similar door per <FIG>. The inventive door passes the side impact pole test with minimal inward intrusion.

Claim 1:
A vehicle component comprising:
a body having a first fixture region and a second fixture region;
a first beam attached to said body and extending between the first fixture region and the second fixture region with a first beam shape, said first beam being formed of a first composite material; and
a second beam attached to said body and extending between the first fixture region and the second fixture region, said second beam being formed of a second composite material and having a second beam shape that is simple compared to the first beam shape wherein the first beam has a first surface area and the second beam (<NUM>) has a second surface area, a ratio of the first surface area to the second surface area being between <NUM>-<NUM>: <NUM>, an outer surface of said first beam (<NUM>) extends outward from a center line relative to an outer surface of said second beam (<NUM>), the outer surface (<NUM>) of said first beam (<NUM>) is positioned a first distance (D1) from a central axis (A) of the body (<NUM>), and the outer surface (<NUM>) of the second beam (<NUM>) is positioned a second distance (D2) from the center line A of the body (<NUM>), wherein the first distance (D1) is greater than the second distance (D2).