Patent Publication Number: US-9840989-B2

Title: Soft engine cover for intake manifold

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Not Applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates in general to decorative covers installed on internal combustion engines for automotive vehicles, and, more specifically, to the mounting of a soft engine cover to an engine and air intake manifold. 
     The engine compartment of a vehicle presents various challenges for vehicle engineers and designers in providing functionality, serviceability, and aesthetics in a relatively small space. Consideration must also be given to manufacturing and assembly costs in addition to weight, which ultimately impacts fuel economy, to deliver a competitive product. An engine cover is typically used in order to enhance the overall appearance of the engine compartment and to reduce the propagation of engine noise. Injection molded polymers are commonly used to fabricate an engine cover. 
     The typical mounting for an engine cover to an engine may be comprised of several steel brackets, fasteners, or other joining structures such as hooks or clamps. The use of several intermediate components which attach on one side to the engine cover and on the other side to an engine component (e.g., an air intake manifold or a cam cover) creates many potential sites for NVH (noise, vibration, and harshness) problems such as squeak and rattle. A relatively large part count leads to added part costs and an associated increase in manufacturing/assembly costs. 
     The air intake manifold which directs incoming air to the respective engine cylinders of a combustion engine has historically been fabricated from metal. More recently, various molded materials including thermoplastics, resins, and polymers have been used to manufacture intake manifolds. Preferred materials may include nylon or other polyamides which may further include filler materials such as glass fibers. A switch to plastic materials has achieved a reduction in weight, but reliance on brackets and fasteners with a high parts count have continued. 
     In co-pending U.S. application Ser. No. 14/525,578, filed Oct. 28, 2014, entitled “Integrally-Molded Intake Manifold Connector for Engine Cover of Combustion Engine,” which issued as U.S. Pat. No. 9,464,607 on Oct. 11, 2016, and which is incorporated herein by reference in its entirety, a hinged connection is disclosed wherein hinge pins extending from radial arms of the engine cover each carry an elastomeric ferrule and wherein the hinge pins are received in slots formed by transverse strips carried by structural ribs of the manifold body. 
     In co-pending U.S. application Ser. No. 14/804,495, filed Jul. 21, 2015, entitled “Hinged Engine Cover for Intake Manifold,” which issued as U.S. Pat. No. 9,551,307 on Jan. 24, 2017, and which is incorporated herein by reference in its entirety, a hinged interface is disclosed wherein C-hooks formed integrally on the intake manifold receive a hinge spindle that is an integrally molded element of the cover. 
     The engine cover is typically fabricated as a one-piece molded article to simplify manufacturing and to lower cost. In order to securely retain the engine cover throughout the service lifetime and harsh conditions in a vehicle, the hinge components must be fairly rigid. Consequently, a nylon or other hard thermoplastic material needed for the hinge element is used to form the entire cover. However, a hard material may be less effective at attenuating noise and vibrations. 
     In addition, fasteners used to secure the cover at the end opposite from the hinge have been relatively difficult to reach and/or manipulate during installation. Thus, it would be desirable to increase noise attenuation while providing an attachment that simplifies installation, reduces parts count, and lowers cost. 
     SUMMARY OF THE INVENTION 
     In one aspect of the invention, apparatus for a motor vehicle comprises an engine assembly having a first hinge portion located at a top, rearward end of the engine assembly, and having first and second structural projections extending upwardly and spaced from the first hinge portion. A cover comprises a rigid substrate and a foam body overmolded onto the substrate. The substrate has an integral second hinge portion to engage the first hinge portion. The foam body has first and second sockets releasably receiving the first and second projections, respectively, to hold the cover at an installed position. The composite engine cover obtains an attractive appearance and good noise absorption characteristics while combining a sufficiently rigid hinge attachment with a snap-in-place fastening system that functions without the need for any tools or removable fastener elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial perspective view of a prior art engine and engine cover. 
         FIG. 2  is a partial cross-sectional, perspective view of a hinged engine cover partially installed on an intake manifold body. 
         FIG. 3  is a top, perspective view of a portion of a prior art molded engine cover including a spindle or pivot pin. 
         FIG. 4  is a rear, perspective view of a portion of a prior art intake manifold including hinge C-hooks for receiving the pivot pin of a cover. 
         FIG. 5  is a perspective view of a composite engine cover according to one preferred embodiment of the invention. 
         FIG. 6  is a perspective view of a molded substrate of the composite engine cover prior to overmolding. 
         FIG. 7  is a perspective view showing the composite engine cover after overmolding of polyurethane foam over the substrate of  FIG. 6 . 
         FIG. 8  is a cross-section view of the cover of  FIG. 7 . 
         FIG. 9  is a bottom view of the composite cover showing sockets for connecting the cover with an engine assembly. 
         FIGS. 10-13  are perspective views of an engine assembly with structural projections for joining with the sockets in the cover. 
         FIG. 14  is a top, perspective view of the cover installed on the engine assembly. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , an internal combustion engine  10  supports an engine cover  11 . Conventionally, cover  11  is rigid and could be comprised of a molded polymeric material such as nylon, PVC, or polyurethane, for example. Cover  11  may include various details for accommodating features and accessories of engine  10 , such as an oil port  12 . Various brackets and/or fasteners are conventionally used to mount cover  11  to various structures of engine  10 . 
       FIGS. 2-4  show improved hinged engine covers as disclosed in the patent applications cited above wherein hinge features are provided at the back end of the engine (e.g., on the air intake manifold) and back end of the cover, and wherein removable fasteners retain the front end of the cover. Thus, an air intake manifold  15  has integrally-molded hinge features  16  for attaching a cover  17  which eliminates the need for a bracket and fasteners at the back end of an engine assembly. Intake manifold  15  may be formed by injection molding a polyamide thermoplastic such as nylon, and may preferably include a filler material such as glass fiber. Hinge features  16  may be associated with a plurality of structural ribs projecting outward from manifold  15 , for example. After engaging cover  17  with hinge features  16 , it is tilted downward and fastened in place over intake manifold  15  and the rest of the engine assembly by fastening a bolt  18  through a corresponding hole in cover  17  and into a threaded bore  19  on intake manifold  19  at the forward end of the engine assembly.  FIGS. 3 and 4  show an embodiment wherein a pivot pin  21  of a cover  20  is configured to mount to C-hooks  22  and  23  in order to form a hinged attachment between cover  20  and an air intake manifold body member  24 . 
     A composite engine cover  30  is shown in  FIGS. 5-9 . Cover  30  has a rigid substrate  31  which is overmolded by a foam body  32 . Rigid substrate  31  preferably includes a generally rectangular frame  33  with a tab extension  34  extending from one end to a molded pivot pin structure  35  to create a portion of a hinge that joins with an engine assembly (not shown). Frame  33  may include overmolded cross-braces  38  following the overall shape of cover  30 . Pivot pin  35  includes alignment flanges  36  and  37  for bearing against corresponding surfaces of a hinge feature on the engine assembly in order to align cover  30  at a desired location. 
     Tab extension  34  projects out from foam body  32  so that pivot pin  35  is not be covered by the overmold. Substrate  31  is preferably molded from nylon or other rigid thermoplastic material, but could also be formed of metal or other rigid materials. Foam body  32  is preferably formed of a polyurethane foam, wherein foaming provides flexibility and improved damping characteristics for attenuating noise and vibration. Foam body  32  has an appropriate size and shape to cover and rest upon the engine assembly, and may be molded with decorative features, logos, or other graphical or textual information. In addition, the compliance/flexibility of foam body  32  is used to create mounting features not needing additional fastener components. In this embodiment, foam body  32  has first and second sockets  40  and  41  for releasably receiving corresponding projections formed on the engine assembly (described below) to hold cover  30  at its installed position. Depending on the structural projection being utilized, socket  40  and  41  may be comprised of a grommet pocket partially penetrating foam body  32  from an underside as shown by socket  40  or may be a passageway extending completely through foam body  32  as shown by socket  41 . The compliance of foam body  32  allows sockets  40  and  41  to stretch in a manner that admits and then captures the corresponding structural projection from the engine assembly. 
       FIGS. 10-13  show an engine assembly  45  adapted to receive cover  30 . Engine assembly  45  may include a pair of cam covers  46  and  47  and an air intake manifold  48  to provide the structural features for the mounting of cover  30 , but other engine components could alternatively be used. In this embodiment, a pair of hinge C-shaped hooks  50  and  51  extend from the intake manifold  48  at a top, rearward end of engine assembly  45  (i.e., at the rear of an engine compartment of the vehicle) configured to receive pivot pin  35  of cover  30 . The spacing and/or width of C-hooks  50  and  51  are adapted to interface with flanges  36  and  37  on pivot pin  35  in order to properly align cover  30  for installation onto engine assembly  45 . For example, flanges  36  and  37  may fit against the inside edges of C-hooks  50  and  51  while pivot pin  35  extends beyond flanges  36  and  37  to engage interior slots of C-hooks  50  and  51 . 
     A first structural projection from engine assembly  45  is comprised of a ball stud  55  extending vertically upward from cam cover  47 . A ball at the end of ball stud  55  is captured by grommet pocket  40  on the underside of foam body  32 . Preferably, interior dimensions of grommet pocket  40  may be configured to match the outer profile of ball stud  55 . Ball stud  55  may be a molded plastic component with its base installed in a matching bore on cam cover  47  by an interference fit, for example. 
     A second structural projection from engine assembly  45  is comprised of an oil filler neck  56  extending vertically upward from cam cover  46 . Corresponding socket  41  on cover  30  comprises a passageway extending through foam body  32  having an internal diameter slightly less than an external diameter of filler neck  56 . Filler neck  56  is snugly captured by the passageway of socket  41  in order to hold cover  30  at its installed position as shown in  FIG. 14 . 
     The foregoing invention combines 1) a hinge and internal frame having sufficiently rigidity to positively align and retain the cover, and 2) a soft covering body with excellent noise and vibration performance together with a desired visual appearance. Manual installation and removal of the cover is done easily and without any tools or removable fasteners.