Patent Application
20100300409
I. Field of the Invention
The present invention relates generally to direct injection internal combustion engines and, more particularly, a fuel system for a direct injection internal combustion engine.
II. Description of Material Art
Direct injection internal combustion engines are becoming increasingly popular in the automotive industry. This increase in popularity results in large part from the fuel economy and engine operating efficiency of direct injection internal combustion engines.
One disadvantage, however, of direct injection internal combustion engines is that such engines require fuel to be delivered to the fuel rail and the fuel injectors at a very high pressure in order to overcome the pressures present in the interior combustion chamber of the engine. In order to achieve these high pressures, a cam driven pump is oftentimes used to pressurize the fuel rail.
Such fuel pumps, however, can cause the fuel rail to vibrate due to the high pressure pulsations produced by the cam driven fuel pump. These vibrations, furthermore, may result in undesirable engine noise, particularly where metallic parts of the fuel system contact and vibrate against other metallic components of the engine or fuel system.
The present invention provides a fuel system for a direct injection internal combustion engine which overcomes the above-mentioned disadvantages of the previously known engines.
In brief, the fuel system of the present invention comprises a fuel rail having at least one direct injection fuel injector assembly connected to the rail at spaced locations there along. Typically, one fuel injector is provided for each internal combustion chamber.
Each fuel injector assembly includes a mounting surface formed around its outer periphery. A dampener constructed of a resilient material is disposed within the fuel injector assembly mounting surface.
A bracket is secured to the engine and includes a recess for each fuel injector assembly. Each fuel injector assembly is positioned within its associated recess so that at least a portion of the dampener is sandwiched between the fuel injector assembly mounting surface and a complementary mounting surface formed along the recess.
A holder is then attached to the bracket for each recess which locks the fuel injector assembly associated with that recess to the bracket. Preferably, the holder includes a mounting surface which is complementary to the fuel injector assembly mounting surface so that a portion of the dampener is sandwiched in between the mounting surfaces on the holder and fuel injector assembly.
In operation, the resilient dampeners mechanically isolate the fuel rail and fuel injector assemblies from the bracket. This, in turn, reduces engine noise.
A better understanding of the present invention will be had upon reference to the following detailed description when read in conjunction with the accompanying drawing, wherein like referenced characters refer to like parts throughout the several views, and in which:
With reference first to
A plurality of fuel injector assemblies 18 are mounted to the fuel rail 16 at spaced positions there along. Although the fuel injector assembly 18 may take different forms, as shown each fuel injector assembly 18 includes a fuel cup 20 which is attached to the fuel rail 14 and fluidly connected to the fuel rail chamber 16 by a fluid passageway 22 (
The fuel cup 20 is open at its lower end and axially slidably receives a direct injection fuel injector 24 within its interior.
A seal 26 fluidly seals the fuel injector 24 to the cup 20 so that fuel from the fuel rail 14 flows through the passageway 22, into the fuel cup 20 into the fuel injector 24. Any means, such as a clip 28, may be used to secure the fuel cup 20 to the fuel injector 24.
With reference still to
With reference now to
A dampener 42 made of a resilient material, such as an elastomeric material or the like, is provided around the fuel injector mounting surface 40. This dampener 42, furthermore, may be either of a two-piece construction, as illustrated in
With reference to
With the fuel injector assembly 18 positioned in its associated recess 36, a holder 50 is associated with each recess 36 to lock the fuel injector assembly in its associated recess. Preferably, the holder 50 includes a mounting surface 52 which is also complementary in shape to the fuel injector assembly mounting surface 40. Consequently, with the holder 50 slid into the open end of the recess 36, a portion of the dampener 40 is sandwiched in between the holder mounting surface 52 and the fuel injector assembly mounting surface 40. Any conventional means, such as staking, adhesive, soldering, welding, or the like may be used to secure the holder 50 in position on the bracket 30.
Although the holder 50 may take many forms, as illustrated, a slide 54 is provided on each side of the holder 50. This slide 54 cooperates with rails 56 formed on both sides of the recess 36 so that the holder 50 may be easily slid into its associated recess 36 and against its associated fuel injector assembly.
In operation, the dampener 42 isolates the bracket 30 from the fuel system 10 and prevents the transmission of vibrations from the fuel system 10 to the engine 12 via the bracket 30. This, in turn, reduces engine noise, particularly at low speeds, such as idle.
Having described our invention, it can be seen that the present invention provides a simple and yet highly effective method for reducing engine noise in a direct injection internal combustion engine. Having described our invention, however, many modifications thereto will become apparent to those skilled in the art to which it pertains without deviation from the spirit of the invention as defined by the scope of the claims.
