Abstract:
An automotive vehicle includes a body with a front portion and a rear portion. The vehicle additionally includes a spoiler coupled to the rear portion. The spoiler includes a first portion, a second portion, and a cap. The first portion includes a first plastic material, the second portion includes a second plastic material, and the cap includes a third plastic material. The second plastic material is distinct from the first plastic material. The second portion is disposed between the first portion and the cap. The second portion has a through hole extending therethrough. The cap has a diameter exceeding that of the through hole. The first portion and the cap are welded together via the through hole to mechanically secure the second portion to the first portion.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates to a system and method of joining plastic components, particularly for assembling a component for an automotive vehicle, and most particularly for assembling a two-piece rear spoiler for an automotive vehicle. 
       INTRODUCTION 
       [0002]    An automotive spoiler refers to an aerodynamic device designed to spoil undesirable air flow across the body of a vehicle. Many vehicles may include a so-called rear spoiler positioned near the top of the rear of the vehicle, e.g. in the vicinity of a vehicle trunk. The rear spoiler is generally provided to reduce drag and, in turn, increase fuel efficiency. However, spoilers may also be provided for stylistic purposes. 
       SUMMARY 
       [0003]    An automotive vehicle according to the present disclosure includes a body having a front portion and a rear portion. The vehicle additionally includes a spoiler coupled to the rear portion. The spoiler includes a first portion, a second portion, and a cap. The first portion includes a first plastic material, the second portion includes a second plastic material, and the cap includes a third plastic material. The second plastic material is distinct from the first plastic material. The second portion is disposed between the first portion and the cap. The second portion has a through hole extending therethrough. The cap has a diameter exceeding that of the through hole. The first portion and the cap are welded together via the through hole to mechanically secure the second portion to the first portion. 
         [0004]    According to various embodiments, the first portion defines an upper surface of the spoiler and the second portion defines a lower surface of the spoiler. 
         [0005]    A variety of plastic materials may be used. According to various embodiments, the first plastic material comprises ABS, ABS+PC, ASA, or ASA+PC; the second plastic material comprises TPO, and/or the third plastic material comprises ABS, ABS+PC, ASA, or ASA+PC. The third plastic material may be distinct from the first plastic material. In an exemplary embodiment, the second plastic material is not weld-compatible with the first plastic material, and the third plastic material is weld-compatible with the first plastic material. 
         [0006]    A method of manufacturing a spoiler for a vehicle according to the present disclosure includes providing a first component, a second component, and a cap. The first component includes a first plastic material, the second component includes a second plastic material, and the cap includes a third plastic material. The second plastic material is distinct from the first plastic material. The second spoiler component has at least one through hole extending therethrough. The diameter of the cap exceeds that of the through hole. The method additionally includes assembling the cap over the hole. The method further includes welding the cap to the first spoiler component through the hole to mechanically secure the second spoiler component to the first spoiler component. 
         [0007]    According to various embodiments, welding the cap includes ultrasonic welding or vibrational welding. 
         [0008]    According to various embodiments, the first component includes a first spoiler component and the second component includes a second spoiler component. 
         [0009]    An apparatus according to the present disclosure includes a first plastic component, a second plastic component, and a cap. The first plastic component has a first material composition, the second plastic component has a second material composition, and the cap has a third material composition. The second material composition is weld-incompatible with the first material composition, and the third material composition is weld-compatible with the first material composition. The second plastic component has at least one through hole extending therethrough, and is disposed between the first component and the cap. The first component and the cap are welded together via the through hole. Thus the second component is mechanically secured to the first component. 
         [0010]    According to various embodiments, the first component includes an upper spoiler component and the second component includes a lower spoiler component. 
         [0011]    According to various embodiments, the third material composition is distinct from the first material composition. The first material composition may include ABS or ABS−PC. The second material composition may include TPO. The third material composition may include ABS, ABS−PC, ASA, or ASA−PC. 
         [0012]    Embodiments according to the present disclosure provide a number of advantages. For example, systems and methods according to the present disclosure enable the assembly, by welding, of dissimilar plastic materials having differing properties. Particularly advantageously, such systems and methods may be used to assemble a two-piece spoiler having an upper portion with a different material composition than a lower portion, where the upper portion is weld-incompatible with the lower portion. 
         [0013]    The above advantage and other advantages and features of the present disclosure will be apparent from the following detailed description of the preferred embodiments when taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is an illustration of a vehicle having a spoiler; 
           [0015]      FIG. 2  is an illustration of a spoiler according to the present disclosure; 
           [0016]      FIGS. 3A-3C  are schematic illustrations of a method of assembling a spoiler according to the present disclosure; and 
           [0017]      FIG. 4  is a flowchart representation of a method of assembling plastic components according to the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations. 
         [0019]    Referring now to  FIG. 1 , a rear portion  12  of a vehicle  10  is shown. A spoiler  14  is provided at the rear portion  12  above a vehicle trunk  16 . The spoiler includes first and second mounting portions  18  for coupling to the vehicle  10  with an aerodynamic portion  20  therebetween. The spoiler  14  may be designed to provide advantageous aerodynamic characteristics and/or for vehicle styling. 
         [0020]    In known designs, a spoiler is made using a single material, as a single piece or as multiple pieces chemically bonded to one another. Typically the single material is a plastic, such as ABS plastic, which is subsequently painted. 
         [0021]    However, for various reasons it may be desirable to form the spoiler out of multiple components of differing materials. For example, it may be aesthetically appealing to generate a visual contrast by providing an upper portion of the spoiler with one color and/or texture and a lower portion of the spoiler with another color and/or texture. 
         [0022]    While differing colors and/or textures for different portions may be technically achievable using a consistent material for the upper portion and lower portion, it may be prohibitively expensive to do so while maintaining desired characteristics. 
         [0023]    For example, differing paints may be used on the upper portion and lower portion to achieve a desired aesthetic effect. However, it may be difficult or unnecessarily expensive to paint an upper portion in one color and paint a lower portion in another color. 
         [0024]    As another example, one portion may be left unpainted to achieve a different color and/or texture. However, it may be undesirable to leave a portion unpainted, because typical ABS plastics are not weatherable, e.g. the color of the unpainted material may degrade when exposed to sunlight. While weatherable plastic materials may be used, they are generally more expensive, and forming a complete spoiler out of a weatherable material and subsequently painting over a portion of the material may incur unnecessary expense. 
         [0025]    Other possible motivations to form the spoiler out of multiple components of differing materials include a desire to form one portion of the spoiler out of material having different structural properties than another portion. 
         [0026]    However, while it may be desirable to form a spoiler out of multiple materials, it may be challenging to join different materials together to form the spoiler using known methods. Different materials may not be weld-compatible, i.e. the different materials may not be chemically bonded via a welding process. As a further consideration, spoilers for automotive vehicles are generally relatively thin aerodynamic components, and as such it may be difficult to implement fasteners to couple multiple components to form a spoiler. 
         [0027]    Referring now to  FIG. 2 , a spoiler  26  according to the present disclosure is shown. The spoiler  26  has first and second mounting portions  28  for securing to a vehicle. The spoiler  26  includes an elongate aerodynamic portion  30  extending between the first and second mounting portions  28 . 
         [0028]    The spoiler  26  includes an upper component  32  and a lower component  34 . The upper component  32  and the lower component  34  are distinct components formed of distinct materials which are weld-incompatible, i.e. are chemically incompatible such that they may not be joined by welding. In an exemplary embodiment, the upper component  32  is formed of a paintable material such as ABS, while the lower component  34  is formed of a weatherable color-in-mold material such as TPO. The upper component  32  and the lower component  34  are mechanically secured to one another by a weld between the upper component  32  and a cap (not shown in this view), as will be discussed below with respect to  FIGS. 3A-3C . 
         [0029]    Referring now to  FIGS. 3A-3C , a method of assembling a spoiler  26  according to the present disclosure is illustrated schematically. The spoiler  26  includes the upper component  32  and the lower component  34 . The lower component  34  includes at least one through hole  36 . According to various embodiments, the holes  36  may be molded into the lower component  34  or provided by machining after molding. As shown in  FIG. 3A , the lower component  34  is assembled in a desired position relative to the upper component  32 . At least one cap  38  is disposed proximate the holes  36 . In this exemplary embodiment, each cap  38  is associated with a single hole  36 . However, in alternative embodiments, a single cap may be associated with multiple holes  36 . The cap  38  has a width that exceeds a width of the associated hole or holes  36 . The cap  38  is positioned to cover the hole  36 , e.g. with protruding portions  40  positioned to abut the lower component  34  about the periphery of the hole  36 . 
         [0030]    As illustrated in  FIG. 3B , a welding tool  42  is applied to the cap  28 . The welding tool  42  is configured to apply heat and pressure to the cap  38 . Under application of the welding tool, the plastic material of the cap  38  is heated through the glass transition. The plastic material of the cap  38  then flows into the hole  36  of the lower component  34 , as illustrated by the arrows. The plastic material of the cap  38  contacts the upper component  32 , and the molecules mix through intermolecular diffusion, forming a chemical bond between the cap  38  and upper component  32 . 
         [0031]    In exemplary embodiments, the welding tool  42  is a friction welding tool or a vibration welding tool. However, other welding techniques and/or other tools for applying heat and pressure may also be used. 
         [0032]    As illustrated in  FIG. 3C , the application of the welding tool  42  is discontinued, and the plastic material of the cap  38  is allowed to cool through the glass transition. The cap  38  is thus chemically bonded to the upper component  32 . The protruding portions  40  of the caps  38  retain the lower component  34  in the desired position relative to the upper component  32 . Thus, the lower component  34  is mechanically secured to the upper component  32 . 
         [0033]    In an exemplary embodiment, the caps  38  are positioned in a section of the lower component  34  which is hidden from sight when installed on a vehicle, thus improving aesthetic appeal of the spoiler  26 . 
         [0034]    While the above joining method is illustrated with respect to the exemplary embodiment of assembling a spoiler, other embodiments within the scope of the disclosure include assembly of other components, including other automotive and non-automotive applications. 
         [0035]    Embodiments according to the present disclosure may be used to assemble a first plastic component and a second plastic component, where the first plastic component and second plastic component have different material compositions, e.g. are weld-incompatible, by welding the first plastic component to a plastic cap. According to various embodiments, the first plastic component and the second plastic component both include thermoplastic material, or the second plastic component may include thermoset material. According to various embodiments, the first plastic component and the second plastic component have differing melting temperatures. According to various embodiments, the cap is formed of the same material as the first plastic component, or a different material that is weld-compatible with the first plastic component. 
         [0036]    As non-limiting examples, the first plastic component may include acrylonitrile butadiene styrene (ABS), ABS-polycarbonate (ABS−PC), acrylonitrile styrene acrylate (ASA), or ASA-polycarbonate (ASA−PC); the second plastic component may include thermoplastic olefin (TPO); and the cap may include ABS, ABS−PC, ASA, or ASA−PC. 
         [0037]    Referring now to  FIG. 4 , a method of assembling plastic components according to the present disclosure is illustrated in flowchart form. The algorithm begins at block  100 . 
         [0038]    A first plastic component is provided, as illustrated at block  102 . The first plastic component is made of a first plastic material. The first material may include ABS or ABS−PC, as illustrated at block  104 . The first plastic component may be a first component of a spoiler, as also illustrated at block  104 . 
         [0039]    A second plastic component is provided, as illustrated at block  106 . The second plastic component is made of a second plastic material. The second material may include TPO, as illustrated at block  108 . The second plastic component may be a second component of a spoiler, as also illustrated at block  108 . 
         [0040]    A cap is provided, as illustrated at block  110 . The cap is made of a third plastic material. The third plastic material may be the same material as the first plastic material or it may be different from the first plastic material, as illustrated at block  112 . The third material may include ABS, ABS−PC, ASA, or ASA−PC, as also illustrated at block  112 . 
         [0041]    A hole is provided in the second component, as illustrated at block  114 . In various embodiments, the hole may be molded into the second component or machined after molding, as illustrated at block  116 . 
         [0042]    The second component is disposed in a desired position relative to the first component, as illustrated at block  118 . In an exemplary embodiment where the first component is a first component of a spoiler and the second component is a second component of a spoiler, the first component may be superposed over the second component to form upper and lower portions of the spoiler, respectively. 
         [0043]    The cap is assembled over the hole, as illustrated at block  120 . In an exemplary embodiment, the cap is positioned in a location that would be hidden from view after assembly, e.g. to preserve a desired aesthetic effect. 
         [0044]    The cap is welded to the first component via the hole, as illustrated at block  122 . This may include friction welding or vibration welding, as illustrated at block  124 . However, other welding techniques and/or other tools for applying heat and pressure may also be used. 
         [0045]    The algorithm ends at block  126 . 
         [0046]    As may be seen, the present disclosure provides a system and method for joining, via welding, plastic components having different material compositions which are otherwise not weld-compatible. Advantageously, such systems and methods may be used to assemble a two-piece spoiler having an upper portion with a different material composition than a lower portion, thus providing pleasing aesthetic effects. 
         [0047]    While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and can be desirable for particular applications.