Snap fuel rail

Abstract: The fuel rail assembly comprises a fuel conduit (38), at least one support (42) connected to the conduit (38), an engine component body (46), and a resilient connector (50) attaching the support (42) to the engine component body (46). The resilient connector (50) can be a resilient insert while the engine component body (46) is preferably an air intake manifold. The support may also be a bracket. The fuel rail assembly further includes at least one fuel injector (54) connected to the fuel conduit (38). The resilient connector, manifold, and fuel conduit are all preferably plastic.

Description: BACKGROUND OF THE INVENTION This invention relates to a means of attaching a fuel rail to an engine component. A fuel rail is a conduit that delivers fuel from the engine's fuel tank system to its fuel injectors and cylinders. There is generally a fuel rail for each bank of fuel injectors and cylinders. For example, an inline six-cylinder engine requires only one fuel rail while a V-6 engine requires two fuel rails. Due to the proximity of the air intake manifold to the engine, manufacturers generally mount the fuel rail to the manifold. Frequently, such a rail is mounted on the engine's manifold by use of a bracket, rigid screw, and rigid fitting that receives the rigid screw. The rigid fitting is typically formed of a metal, such as brass, and embedded into the plastic manifold by heating the brass fitting to a temperature sufficient to melt the plastic and embed the fitting into the plastic. Each bracket of the fuel rail is then placed over each brass fitting and attached to the fitting by turning the screw for each bracket into each brass fitting. This manner of attaching the fuel rail to the manifold, however, is time-consuming. Each brass fitting must be heat installed into the manifold and a screw turned into each fitting. Moreover, the use of a metal screw and metal fitting makes the recycling of the plastic from the manifold costly as each metal screw and metal fitting must be removed prior to recovery of the plastic. A need therefore exists for a means of quickly and conveniently connecting the fuel rail to the manifold while permitting the recycling of the plastic of the manifold. WO 97/30282 and US 6,148,799 describe a method and an assembly for a snap fuel rail. SUMMARY OF THE INVENTION The present invention accordingly provides methods and apparatus as recited in the appended claims. Preferably, the fuel rail assembly is attached by first inserting the resilient insert into a hole in a flange of the manifold. The insert is then vibration welded into place. The support, either molded as part of the fuel conduit or assembled with the conduit, receives the resilient insert through its hole. Because the resilient insert has non-flexed dimension greater than the hole of the flange and the support, the insert must be forced through the hole with sufficient force to reduce the insert to its flexed dimension, which is smaller than the hole. The assembly is thus "snapped" into place. Once in place, the insert expands locking the bracket and conduit into place. In this way, the fuel rail assembly may be quickly attached to the engine's manifold. No brass fitting need be embedded into the manifold and no screw is required. Moreover, because the insert, bracket, fuel rail, and manifold are all polymer, they may be all recycled together. BRIEF DESCRIPTION OF THE DRAWINGS The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows: Figure 1A shows a fuel rail assembly as known in the art. Figure 1B shows a detail view of a portion of the fuel rail assembly of Figure 1A. Figure 2 shows an embodiment of the invention on a manifold. Figure 3 shows an exploded view of the embodiment of Figure 2. Figure 4 shows the resilient connector of Figures 2 and 3. Figure 5 shows a side view of the resilient connector of Figures 2, 3, and 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 1A shows a fuel rail assembly known in the art. Fuel conduit 10 is mounted to manifold 14. Fuel injectors 18 serve to inject fuel into the engine's cylinders from fuel conduit 10. A tab 22, here shown as molded to fuel conduit 10, permits the attachment of fuel conduit 10 to post 26 through brass screw 30. Post 26 is also molded to manifold 14. Embedded within post 26 is brass fitting to receive brass screw 30. As seen in Figure 1B, brass fitting 34 is within post 26. Figure 2 shows an embodiment of the invention. The fuel rail assembly comprises fuel conduit 38, at least one support 42 operatively connected to fuel conduit 38, engine component body 46, and resilient connector 50 operatively attaching the support 42 to the engine component body 46. It is preferred that at least two supports are used for each fuel conduit. Fuel conduit 38 delivers fuel to engine cylinders through at least one fuel injector 54. As pictured, engine component body 46 is preferably an air intake manifold. Fuel conduit 38, support 42, resilient connector 50 are preferably a recyclable polymer such as plastic to permit recovery of this material in the recycling process. Figure 3 shows an exploded view of the embodiment of Figure 2. Shown are fuel conduit 38, at least one support 42, engine component body 46, resilient connector 50, and fuel injector 54. Here, resilient connector 50 is more clearly shown as a resilient insert with two legs 60A and 60B beneath hole 64 in manifold 46, which is located on flange 68, molded as part of manifold 46. Support 42, which is a bracket, also has a hole 70. Figures 4 and 5 show a detailed view of resilient insert 50. Resilient insert 50 is made of a resilient material such as a polymer like plastic although an individual with ordinary skill in the art may employ other resilient materials. Here, resilient insert 50 has insert portion 62 (shown by shading) comprising leg 60A and leg 60B and lip 76A and lip 76B. Base 80 (not shaded) mounts legs 60A and 60B together. As seen in Figure 5, lips 76A and 76B of resilient insert 50 have non-flexed dimension A in a relaxed state, greater than the inner dimension of holes 64 and 70. In an inwardly flexed position a dimension B (the outer dimension of both legs) is smaller than the inner dimension of holes 64 and 70. As can be seen from Figure 5, resilient insert 50 is inserted in hole 64 in the direction of arrow C. As insert portion 62 of resilient insert 50 is passed through hole 64, contact between lips 76A and 76 B and flange 64 forces lips 76A and 76B and thus legs 60A and 60B inwardly to a distance B and permits insertion of insert portion 62 of resilient insert 50 into holes 64 in direction C beyond lips 76A and 76B. Resilient insert 50 is then vibration welded into place on flange 68. Hole 70 of bracket 42 is then placed over the vibration welded resilient insert 50 and forced in a direction opposite of arrow C over insert portion 62 of resilient insert 50. As insert portion 62 of resilient insert 50 passes through hole 70, contact with lips 76A and 76B forces the lips to distance B and permits insertion of resilient insert 50 into hole 70 beyond lips 76A and 76B. Once lips 76A and 76B pass through hole 70, resilient insert 50 expands to distance A, thereby locking support 70 and flange 68 together. Of course, the insert 50 could be formed with body 46 when molded, but is preferably separate.

Claims: An assembly comprising: a fuel conduit (38); at least one bracket (42) operatively connected to said fuel conduit; a flange (68) as part of an engine component body (46); and a resilient connector (50) operatively attaching said at least one bracket to said flange, wherein: said resilient connector (50) is a resilient insert with an insert portion (62); - said flange (68) and said bracket (42) each having respective planar parts each including a hole (70, 64) to receive said insert portion; and wherein the insert portion (62) comprises first (60A) and second (60B) legs and first (76A) and second (76B) lips provided thereon; and a planar base (80) upon which are mounted said legs (60A, 60B); said lips (76A, 76B) having a non-flexed dimension (A) greater than the inner dimension of the holes (64 and 70), and an inwardly flexed dimension (B) smaller than the inner dimension of the holes (64, 70). The assembly of claim 1 wherein said resilient connector (50) is separately formed from said fuel conduit (38). The assembly of any preceding claim wherein said resilient connector (50) is vibration welded to said engine component body (46). The assembly of any preceding claim further including at least one fuel injector operatively connected to said fuel conduit (38). The assembly of any preceding claim wherein said resilient connector (50) is formed from a polymer. The assembly of any preceding claim wherein said engine component body (46) is formed from a polymer. The fuel rail assembly of any preceding claim wherein said at least one bracket (42) is formed from a polymer. The assembly of any preceding claim wherein said engine component body (46) is a manifold. A method of mounting a fuel rail assembly comprising the steps of: providing a bracket (42) which has a planar portion including a hole (70) for receiving a resilient connector (50), operatively connected to a fuel conduit (38); providing a flange (68) which has a planar portion including a hole (64) for receiving a resilient connector, as part of an engine component body (46); and attaching respective planar parts of said bracket and said flange by passing a resilient connector (50) through the respective holes (64, 70),wherein the resilient connector (50) has an insert portion (62) comprising first (60A) and second (60B) legs and first (76A) and second (76B) lips provided thereon; and a planar base (80) upon which are mounted said legs (60A, 60B); said lips (76A, 76B) having a non-flexed dimension (A) greater than the inner dimension of the holes (64 and 70), and an inwardly flexed dimension (B) smaller than the inner dimension of the holes (64 70); and further the method comprises the step of: inserting the insert portion (62) through the respective holes (64, 70), whereupon as insert portion (62) is passed through the holes (64, 70), contact between the lips (76A, 76B) and the perimeter of the hole forces the lips thus the legs inwardly to achieve said inwardly flexed dimension whereby the insert portion is inserted into the hole beyond the lips the resilient insert thereupon expanding to the non-flexed dimension, thereby locking the fuel conduit and the engine component body together. A method according to claim 9, further comprising the step of vibration welding the resilient connector (50) into place on said engine component body (46).

Inventors: KEHOE JON-DAVID, KEHOE, JON-DAVID
Applicants: SIEMENS VDO AUTOMOTIVE INC, SIEMENS VDO AUTOMOTIVE INC.
Application year: 2001
Main classification: F02M61
IPC codes: F02M61, F02M69