Trunk mounted fuel tank assembly

A trunk mounted fuel tank assembly including a cradle, a fuel tank, and at least one retention strap is disclosed. The cradle includes a back portion and bottom portion with a fuel feed passage that is placed over a surface of a trunk. The fuel tank includes a fuel line that is placed about the back portion and bottom portion of the cradle. The fuel line extends through the fuel feed passage and a passage in the surface of the trunk. The at least one retention strap includes a first leg and a second leg that is placed over a top portion of the fuel tank for retaining the fuel tank to the cradle.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to fuel tank assemblies, and in particular to a fuel tank assembly mounted in the trunk of a vehicle.

Typically, vehicular fuel tanks may be mounted in a body-on-frame or underbody configuration. In either configuration, operator access to the fuel tank for installation or service is typically not hindered. Alternatively, when space for mounting the fuel tank in the above configurations is unavailable, fuel tanks may be mounted in the trunk of a vehicle.

However, when fuel tanks are mounted in the trunk of the vehicle, operator access for installation or service tends to be limited as a result of the available space restrictions imposed by the design of the trunk. Even further, during a “blind installation” (i.e. when the fuel tank obstructs the operator's view) of a conventional trunk-mounted fuel tank, the operator may not be able to rigidly fasten and retain the fuel tank to an underlying surface of the trunk.

Therefore, a need exists for a device that maintains and retains a trunk mounted fuel tank in a position that does not hinder operator access for installation and service.

SUMMARY OF THE INVENTION

In a first embodiment of the invention, a trunk mounted fuel tank assembly is described. The trunk mounted fuel tank assembly comprises a cradle, a fuel tank, and at least one retention strap. The cradle includes a back portion and bottom portion with a fuel feed passage that is placed over a surface of a trunk. The fuel tank includes a fuel line. The fuel tank is placed about the back portion and bottom portion of the cradle. The fuel line extends through the fuel feed passage and a passage in the surface of the trunk. The at least one retention strap including a first leg and a second leg is placed over a top portion of the fuel tank for retaining the fuel tank to the cradle.

Another embodiment of the trunk mounted fuel tank assembly includes a cradle comprising a first flange with a key passage and an integral wedge portion that extends from the back portion of the cradle. The first flange permits fastening of the cradle to the surface of the trunk by a welded stud including a key portion and a wedge-receiving portion that extends from the surface of the trunk. The wedge-receiving portion guides the stud about a channel of the key passage that extends through the wedge portion. The cradle includes a second flange that extends from the bottom portion of the cradle and includes a first fastener passage. The fuel tank also includes an enclosure comprising a blow-molded high-density polyethylene that conforms to and encapsulates an outer surface of the fuel tank. The enclosure terminates near a fuel line interface that extends through the surface of the trunk and out to the underbody of the vehicle. The second leg of the at least one retention strap is connected to the back portion of the cradle. The first leg of the at least one retention strap includes a second fastener passage that permits a bolt to extend through the first and second fastener passage for connecting the at least one retention strap to the cradle and surface of the trunk. The cradle and at least one retention strap comprises stamped steel.

Another embodiment of the trunk mounted fuel tank assembly comprises means for maintaining a fuel tank, means for retaining the fuel tank, blind installation means, fuel tank rigidifying and liquid loss drainage means, and fuel line protection means.

Various additional aspects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 1, a trunk mounted fuel tank assembly, which is shown generally at10, comprises at least a fuel tank12, means for maintaining the fuel tank12, such as a cradle14, and means for retaining the fuel tank12, such as at least one retention strap16. The cradle14and retention straps16may comprise any desirable rigid material, such as steel, that is stamped into any desirable configuration that maintains and retains the fuel tank12. Essentially, as explained in further detail below, the fuel tank assembly10provides isolation of the fuel tank12, a robust fuel line interface, and promotes fuel drainage during a vehicular crash event, while also lending support and providing serviceability to the fuel tank12and other associated components.

The fuel tank assembly10resides on a surface, which is generally indicated at S, in the trunk of a vehicle. The surface, S, may be any desirable surface in the trunk of the vehicle such as, for example, a surface located forward or behind the rear axle of the vehicle. As illustrated, the fuel tank12may be anchored to the surface, S, by first placing the fuel tank12over a bottom portion18of the cradle14that includes a fuel feed passage20. Once the fuel tank12is properly positioned about the cradle14, the retention straps16are placed over the a top portion22of the fuel tank10such that a first leg24and a second leg26of each retention strap16is connected with a first flange portion28and a back portion30of the cradle14, respectively.

Each first leg24includes a first fastener passage32for receiving a fastener34, such as a bolt or screw. Once the fastener34is passed through the first fastener passage32, the fastener34is then passed through a second fastener passage36that is located about the first flange portion28that adjacently overlies a surface passage, P, of the surface, S, so that the fastener34may secure the retention strap16to the cradle14and the cradle14to frame rails (not shown) below the surface, S.

Each second leg26of the retention straps16may be further defined to include any desirable shape, such as a t-shaped section35, that matingly cooperates with a second leg reception passage38located on the back portion30. Accordingly, as illustrated, a head portion40of the t-shaped section35is inserted through a mouth42of the reception passage38. Then, a neck portion44of the t-shaped section35is passed through a throat portion46of the reception passage38. The neck portion44and throat portion46are designed to have a smaller width than the head portion40and mouth portion42so that the t-shaped section35of the second leg26may be removeably attached from the back portion30of the cradle14during a service or installation procedure in order to gain access to the fuel tank12. As illustrated, each second leg26may be detached from the back portion30by applying pressure in the direction as illustrated by the arrow, D, near the neck portion44of the t-shaped section35.

The back portion30of the cradle14may also be secured to the surface, S, by fasteners34that pass through a second flange portion48; however, the second flange portions48may face a trunk wall (not shown), resulting in a blind installation of the cradle14. Therefore, in order to accommodate a blind installation of the cradle14prior to fastening the retention straps16, the second flange portions48may also comprise blind installation means, such as a key passage50with an integral wedge portion52.

In this embodiment of the invention, the second flange portion48is designed to receive a protrusion, such as a welded stud54that extends from the surface, S, of the trunk. The stud54may include a key portion56and a wedge-receiving portion58. Essentially, the key portion56is designed to matingly pass through the key passage50during a blind installation of the cradle14, and the wedge-receiving portion58is designed to guide the stud54about a channel60of the key passage50that extends through the wedge portion52.

In operation, the second flange portion48permits the anchoring of the cradle14to the surface, S, and once the stud54is received by the flange portion48, a “preload” is created that rigidly retains the cradle14to the surface, S, as a result of the plastic deformation of the wedge portion52by the stud54. The overall combination of the stud54and fasteners34with the cradle14and retention straps16lends stiffness and robustivity to the fuel tank12while also providing a fuel tank assembly10that provides structure and isolation of the fuel tank12during a crash event.

Referring now toFIG. 2, the fuel tank12may also comprise fuel tank rigidifying and liquid loss drainage means, such as an enclosure62, that encapsulates an outer surface of the fuel tank12, which is shown generally at64. The enclosure62may comprise any desirable fire-retardant or plastic material, such as a high-density polyethylene, and may be blow-molded so that it may conform to the outer surface64. Essentially, the enclosure62provides a rigid “clam shell” shield that protects the fuel tank12and channels potential liquid loss during a crash event from the vehicle interior, I, to the vehicle exterior, E. Essentially, the enclosure62is illustrated to terminate near a fuel line interface66that extends through the surface, S, and out to the underbody of the vehicle, thereby forming an integral drain for the fuel tank assembly10.

Referring toFIGS. 2 and 3, the fuel line interface66comprises at least a pump68within the fuel tank12, a sealant70, and a fuel line72. The sealant70may comprise any desirable material, such as rubber, that is intermediately located between the enclosure62and the bottom portion18about the fuel feed passage20so that moisture from the exterior, E, may not enter the interior, I. The fuel line72is illustrated to run underneath the vehicle for supplying fuel to the engine.

Referring specifically toFIG. 3, which is referenced from a dashed line, M, inFIG. 2, the fuel line interface66may further comprise an integral forward flow check valve74. In operation, the forward flow check valve74prevents inadvertent liquid drainage from the fuel tank12if separation of the fuel line72or integrity degradation of the fuel tank12were to occur. In operation, the forward flow check valve arrangement74opens to fuel flow at elevated pressures causes by the fuel pump68. As illustrated, the fuel line72and a quick connect supply line76are intermediately connected by the forward flow check valve arrangement74that comprises a body78with sealing threads80, a threaded weld nut82, and fuel line connections84. The fuel line connections84may be any desirable connecting element, such as a quick connect, a push-on type, or threaded fastener type. The forward flow check valve arrangement74pierces the outer surface64of the fuel tank and may be sealed by a weld86about a bottom perimeter88of the threaded weld nut82.

The weld nut82is located over a fuel line protection means, such as a recessed boss90, that elevates (i.e. indents) the outer surface64of the fuel tank12about the forward flow check valve arrangement74at a height, H. In operation, the recessed boss90firstly provides a flat surface92that permits the weld nut82to sit adjacently flush with the outer surface64in order to permit increased sealing characteristics. Secondly, the recessed boss90positions the forward flow check valve arrangement74off a normal bottom94of the fuel tank12and thereby prevents the fuel line72or the forward flow check valve arrangement74extending from the fuel feed passage20from snapping or breaking. Thirdly, because the recessed boss90is distanced at the height, H, the recessed boss90protects the forward flow check valve arrangement74from water ingress, or other contaminates that attempt to enter and corrode the fuel tank assembly10about the fuel passage20.

Accordingly, as described above, the fuel tank assembly described above provides blind installation means, fuel tank rigidifying and liquid loss drainage means, and fuel line protection means, means for maintaining the fuel tank, and means for retaining the fuel tank. Essentially, the fuel tank assembly does not hinder operator access for installation and service of the fuel tank by permitting an operator to removably attach retention straps from the cradle. Even further, because the fuel tank assembly is an add-on structure that is not integral with the material of the trunk, the fuel tank may be located at any desirable location within the trunk.

Although certain preferred embodiments of the present invention have been described, the invention is not limited to the illustrations described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention. A person of ordinary skill in the art will realize that certain modifications and variations will come within the teachings of this invention and that such variations and modifications are within its spirit and the scope as defined by the claims.