Engine compartment cover

A vehicle includes a body defining an engine compartment and a plurality of vehicle frame members. An engine compartment cover defines a portion of the engine compartment and functions as a structural load-bearing portion of a vehicle frame by rigidly, structurally interconnecting vehicle frame members.

TECHNICAL FIELD

The present invention relates to vehicular engine compartment covers that function as vehicle frame portions by structurally interconnecting vehicle frame members.

BACKGROUND OF THE INVENTION

Motor vehicle front ends typically have a plurality of structural load-bearing frame members. The load-bearing frame members partially form or surround an engine compartment used to house various vehicular components, including steering system components, braking system components, and propulsion system components.

The load-bearing frame members may be subjected to significant stresses. A suspension system with wheels is mounted with respect to at least some of the load-bearing frame members, and transfers loads to frame members. These loads are caused by forces encountered in regular vehicle operation: irregularities in the road exert a vertical force on wheels that are transmitted to frame members; forces related to the linear acceleration or deceleration of the vehicle relative to a road surface are transmitted from the wheels to frame members; and forces related to the lateral acceleration of the vehicle relative to the road surface are transmitted from the wheels to frame members. Furthermore, the vehicular components in the engine compartment are mounted to at least some of the load-bearing frame members, which therefore bear the weight of the vehicular components.

A hood is typically employed to conceal and protect the vehicular components in the engine compartment. The hood opens to provide access to the engine compartment for maintenance and repair of the powerplant and other components. In the prior art, the hood is fixed at only three points, via two hinges, usually placed at the rear of the hood at or near a cowl, and via a releasable latch located at or near an upper tie bar. These three connection points are not totally rigid which allows the conventional hood to pivot relative to the vehicle's body structure. The prior art hood is thus not suited for bearing loads from, or distributing loads among, structural load-bearing frame members in prior art motor vehicles.

SUMMARY OF THE INVENTION

A vehicle is provided that includes a vehicle body at least partially defining an engine compartment. The vehicle also includes a vehicle frame, which may or may not be integral with the body. The vehicle frame has a plurality of frame members, including a cross member and at least two rails mounted with respect to the cross member. A load-bearing, structural engine compartment cover defines at least a portion of the engine compartment and is rigidly mounted to at least two of the frame members so that the engine compartment cover is configured to transfer loads between the two frame members irrespective of load vector. The engine compartment cover thereby forms a portion of the vehicle frame by structurally interconnecting the two frame members. A hood is pivotably connected to the vehicle body for selective movement between an open position and a closed position in which the hood extends over the engine compartment and the engine compartment cover.

Because the engine compartment cover can distribute loads among frame members, each of the individual frame members carries less of a load than it would in a comparable vehicle without the engine compartment cover. A vehicle employing the structural load-bearing engine compartment cover may therefore have smaller or fewer load-bearing frame members than a comparable vehicle without the engine compartment cover. The engine compartment cover may also improve under-hood vehicle aesthetics.

The above features and advantages, and other features and advantages, of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIG. 1, a vehicle10includes a vehicle body14that defines an engine compartment18forward of a passenger compartment20. The vehicle10also includes an engine compartment cover22that extends over and above the engine compartment18to define at least a portion of the upper extent of the engine compartment. The engine compartment cover22includes is two-ply, i.e., the cover22includes two panels26,30in juxtaposition with one another and operatively joined together. Panel26defines the upper surface34of the cover22, which is characterized by aesthetic features such as contours38. Panel30extends below panel26, and the periphery42of panel30is hemmed around the periphery of panel26.

A portion46of panel26is contoured such that the upper surface34at portion46is convex, with a corresponding concavity forming a channel48that opposes panel30. The channel48cooperates with panel30to define an airflow passageway52having an opening56at the forward end of the engine compartment cover22. The opening56of passageway52is in airflow communication with a vehicle grill (shown at58inFIG. 2) to receive airflow when the vehicle10is in motion. The channel48is configured to direct airflow as desired by the design of the vehicle for heat management of vehicular components, ventilation, etc.

The panels26,30are preferably each one piece of metal and formed using sheet hydroforming, quick plastic forming, or superplastic forming; however, other forming techniques may be employed within the scope of the claimed invention. Quick plastic forming is described in U.S. Pat. No. 6,253,588, issued Jul. 3, 2001 to Rashid, et al, which is hereby incorporated by reference in its entirety. Superplastic forming is described in U.S. Pat. No. 5,974,847, issued Nov. 2, 1999 to Saunders, et al, which is hereby incorporated by reference in its entirety. Alternatively, and within the scope of the claimed invention, a cover22may be a single ply, i.e., formed by a single sheet.

The vehicle10also includes a vehicle frame, which may or may not be integral with the body14within the scope of the claimed invention. The vehicle frame has a plurality of structural load-bearing body frame members, including a pair of upper rails59that extend longitudinally with respect to the vehicle10and are spaced apart from one another; mid-rails62(also sometimes referred to as “lower rails”) that are situated lower than the upper rails, that extend longitudinally with respect to the vehicle10, and are spaced apart from one another; cross members such as a cowl bar65; an upper tie bar68; front hinge pillars71; and front wheelhouses74having shock towers (not shown).

The upper rails59extend from the front hinge pillars71forward to the upper tie bar68. The upper tie bar68extends transversely and interconnects the forward ends of the upper rails59. The cowl bar65extends substantially transversely and interconnects the rearward ends of the upper rails59. The mid rails62are inboard of the upper rails59to accommodate wheels. Front wheelhouses74extend from the mid rails62to the upper rails59. Shock towers house various suspension components (not shown).

The engine compartment18may include an engine (not shown), steering system components (not shown), braking system components (not shown), etc. The term “engine compartment” is non-limiting with respect to the nature or type of powerplant employed; thus, within the scope of the claimed invention, the vehicle10may employ any powerplant, such as a conventional internal combustion engine, an electric motor, a fuel cell, a hybrid-electric system, etc.

The engine compartment cover22is rigidly mounted with respect to each of the upper rails59, cowl bar65, and upper tie bar68. In the context of the present invention, the engine compartment cover22is “rigidly mounted” with respect to a frame member if a connection or fastening device between the cover22and the frame member is configured to bear and transfer loads and moments between the cover22and the frame member irrespective of load vector. For example, the cover22would not be rigidly mounted to a frame member if the only locking or fastening element interjacent the cover22and the frame member is a hinge; by design, a hinge cannot support a moment, and the engine compartment cover22could pivot relative to the frame member.

Those skilled in the art will recognize a variety of rigid and releasable fasteners and fastening systems that may be employed within the scope of the claimed invention to rigidly connect the cover22to the frame members. In the embodiment depicted, the cover22defines a plurality of holes78. Three holes78align with holes or clinch nuts (not shown) on one of the upper rails59, three holes78align with holes or clinch nuts (not shown) on the other upper rail59, three holes78align with holes or clinch nuts (not shown) on the upper tie bar68, and three holes78align with holes or clinch nuts (not shown) on the cowl65. Threaded fasteners (not shown) are inserted through holes78to engage the holes or clinch nuts on the frame members59,68,65to rigidly connect the cover22to each of frame members59,68,65.

The loads borne by the frame members are smaller than those of conventional vehicles because the load-bearing engine compartment cover22distributes loads among the frame members. As a result, the frame members need not be as large or prominent as they are in the prior art. For example, the upper rails59, cowl bar65, and upper tie bar68may have an open section form, as opposed to a closed box form found in the prior art.

The cover22provides access points for various engine compartment components. More specifically, a battery82is located in the engine compartment18, and includes two terminals86. The cover22defines two apertures90. Each aperture90is positioned to align with a corresponding one of the terminals86such that each terminal86extends through a corresponding one of the apertures90. The cover22also defines three fluid-fill apertures94A,94B,94C that align with the opening of a corresponding fluid conduit98A,98B,98C, respectively, in the engine compartment. In the embodiment depicted, conduit98A is in fluid communication with a windshield solvent reservoir (not shown); conduit98B is in fluid communication with a radiator (not shown); and conduit98C is in fluid communication with an engine crankcase (not shown). Removable plastic caps (not shown) may be employed to cover the apertures94A,94B,94C.

In the embodiment depicted, the cover22also defines a storage pocket102formed between panels26,30for storage of items such as a flashlight, a funnel for use with the fluid fill apertures, a jack, a squeegee, etc.

Alternatively, and within the scope of the claimed invention, the cover may be rigidly connected to the two mid-rails62and a lower cross-member106that interconnects the forward ends of the mid-rails62such that the cover defines at least a portion of the lower extent of the engine compartment thereby to function as a belly pan.

Referring toFIG. 2, wherein like reference numbers refer to like components fromFIG. 1, the vehicle body14is shown with fenders110attached to the upper rails (shown at59inFIG. 1). A hood114is pivotably connected to the upper rails or the cowl via hinges118for movement between a closed position, as shown inFIG. 2, and an open position in which the hood114is pivoted about the hinges118. In the closed position, the hood114extends above and across the entire engine compartment and engine compartment cover22, such that the hood is in juxtaposition with the cover22.

As set forth in the claims, various features shown and described in accordance with the different embodiments of the invention illustrated may be combined.

While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the scope of the invention within the scope of the appended claims.