The field of the present invention is air and fuel delivery system arrangements for reciprocating piston, internal combustion engines. The present invention relates particularly to V-type internal combustion engines having spark-ignited, multiple injector fuel systems.
In order to increase fuel economy, there has been a constant quest to reduce the physical envelope of the vehicle engine so that the engine compartment may be made smaller to accomplish aerodynamic improvements in the overall vehicle. Additionally, another trend to improve vehicle fuel economy is to go to fuel injection systems wherein each engine cylinder receives fuel from an individualized fuel injector.
Most V-type automotive engines utilize two separate fuel manifolds (more commonly referred to as fuel rails), which deliver fuel pressurized by a fuel pump to a group or bank of fuel injectors. In most applications, the fuel rails are connected to brackets. The brackets typically are spaced apart and an air manifold is placed between the two separate fuel rails. It is well known to those skilled in the art that many automotive vehicles which utilize fuel injectors, require some method of dampening pressure pulsations (caused by the rapid opening and closing of the fuel injectors) within the fuel rail so that there may be an accurate delivery of fuel by the fuel injectors.
Initially, fuel pressure pulsations were mainly dampened by the addition of a pressure dampener connected directly to the fuel rail or via a line leading to the fuel rail. Increasingly, it has been desirable to eliminate using a separate component damper and to utilize the fuel rail itself for dampening pulsations. This tendency of utilizing the fuel rail itself to dampen pulsations has caused the overall size of fuel rails to generally increase.
It is desirable that the space envelope taken up by the fuel delivery system of the vehicle be minimized due to overall engine compartment space considerations. It is desirable to provide an air fuel delivery system wherein for a V-type engine, both fuel rails may be placed in a more central location.
To make manifest the above-noted and other desires, a revelation of the present invention is brought forth. In a preferred embodiment, the present invention provides an air fuel delivery system arrangement for a V-type reciprocating piston internal combustion engine. The arrangement includes a portion of the air manifold body having a first set of runners for a first engine cylinder bank having air inlets on a first side and air outlets on a second side. A second set of runners is provided, having air inlets on the second side and air outlets on the first side for delivering air to a second bank of cylinders of the engine. A first fuel rail is provided which has cupped injector outlets which are generally aligned with fuel injector inlets for the first engine bank. The first fuel rail is positioned between the inlets of the first and second sets of runners of the air manifold.
A second fuel rail is also provided. The second fuel rail has a series of cupped outlets also. The second fuel rail delivers fuel via fuel injectors which are connected between the second fuel rail and fuel injector inlets for the second bank of engine cylinders. The second fuel rail is positioned generally vertically adjacent with the first fuel rail.
The present invention is advantageous in that it allows the fuel rails to be placed generally vertically aligned with each other and also allows their placement at a central point of the engine when utilizing V-type engines. Additionally, the inventive fuel air delivery system arrangement allows for easier installation of the fuel injectors between the fuel rails and the fuel injector inlets and also allows for placement of the fuel injectors in such a manner that minimizes opportunities for damaging the fuel injector due to misalignment during assembly.
Further features and advantages of the present invention will become more apparent to those skilled in the art after a review of the invention as it is shown in the accompanying drawings and detailed description.
Referring to
The arrangement 7 includes an air manifold body 10. The air manifold body 10 is typically a molded thermoplastic polymeric material such as Nylon®, plastic or can be aluminum or other suitable material. Often, the material will be fiberglass reinforced. The manifold body has a first set of runners 12. The runners 12 have air inlets 14 on a first side 16 of the air manifold body. The air manifold body 10, on its second side 18, has a series of air outlets 20 for the runners 12. The air outlets 20 deliver air to a first cylinder bank 22 of a spark-ignited, internal combustion engine 24 (
In a similar manner, the air manifold body 10 has a second set of runners 26, with air inlets 28 on side 18 of the air manifold body and air outlets 30 on side 16 of the air manifold body. The second set of runners 26 deliver air to the cylinders of the engine 24 on a second bank 32.
The air manifold body 10 has a series of outer fastener towers 34 to allow the air manifold body to be connected to an upper portion of the air manifold (not shown). A set of fastener apertures 25 allow the air manifold body 10 to be connected with a head of the engine 24. The air manifold body 10 also has two (only one shown in
The air manifold body 10, for each runner, has a fuel injector inlet 38. The fuel injector inlet 38 allows for insertion of a fuel injector to allow the fuel injector outlet (not shown) to disperse fuel into a passage which is in close proximity with the runner.
The air fuel delivery system arrangement 7 of the present invention includes a fuel rail combination 44. The fuel rail combination 44 includes a first generally elongated fuel rail 46. The first fuel rail 46 has a fuel inlet 48. The fuel inlet 48 is connected via a hose 50 (
The first fuel rail 46 has an elongated body 62. The fuel rail elongated body 62 has an upper thin stamped female clamshell member 64 which is sealably joined (usually soldered) to a stamped thicker male clamshell member 66. The stampings of the first fuel rail body 62 are essentially identical to the male and female clamshell stampings which make up the second fuel rail 58, with the exception that the second fuel rail 58 has its inlet connected with its top thin female clamshell stamping 68 rather than its lower clamshell stamping 70.
Typically, the female clamshell stamping 64 will be of stainless steel or mild carbon steel having a thickness and range between 0.010 to 0.035 inch. The thick male clamshell stamping 66 will be made of the same material, typically having a thickness in the range of 0.030 to 0.045 inch. The thinness of the female clamshell stamping allows the first fuel rail 46 to be self damping, allowing the upper female clamshell member 64 to absorb pressure pulsations caused by the opening and closing of the fuel injectors connected with the first fuel rail 46.
The thick male stamping 66 has connected thereto three cupped outlets 72. The cupped outlets receive the upper inlet end of the fuel injectors 40. The first fuel rail 46 delivers fuel to the cylinders of the first engine bank 22. The second fuel rail 58 delivers fuel to the second engine bank 32. The main body 62 on the first fuel rail has its male stamping 66 connected with a bracket 73. The bracket 73 is mated with a bracket 76 which is in turn fixably connected with the second fuel rail 58. The brackets 73, 76 have aligned apertures to allow a fastener (not shown) to connect the two brackets to the fuel rail connection tower 36. As shown in
The brackets 73, 76 by virtue of their connection with their respective male stamped clamshell members do not inhibit the absorption of vibration by the female stamped clamshell members and additionally, are offset so that there is always a clearance between the first and second fuel rails 46, 58.
The cupped outlets 72 of the first fuel rail extend angularly toward the first cylinder bank of the engine for a first given distance, typically 8–15 mm. The cupped outlets 74 of the second fuel rail angularly extend in the opposite direction toward the first cylinder bank 32. The second fuel rail angularly extends outward generally opposite the direction of the cupped outlets 72 toward the second cylinder bank 32.
Since the second fuel rail 58 is aligned generally above the first rail 46, its cupped outlets 74 extend outward typically 25–35 mm, which is a greater distance than the cupped outlets 72. Accordingly, the fuel injectors associated with the second set of runners will have their outlets positioned generally the same as the fuel injectors associated with the first set of runners.
The fuel rail connection brackets 73, 76, in combination with the tower 36 position the fuel rail combination 44 such that the fuel rails are positioned generally between the area next to 14, 28 of the runners. Additionally, the fuel injector combination 44 is typically, but not required to be positioned so that the top surface 84 of the second fuel rail main body is lower than the top surface of the air manifold body 10.
During vehicle assembly, typically the fuel rails 46, 58 will be fluidly connected via the hoses 50, 54. First fuel rail 46 will then be connected with the manifold body 10. Fuel injectors 40 will have their inlet ends sealably connected and inserted within the cupped outlets 72 of the first fuel rail and the outlet end of the fuel injectors 40 will have their outlet ends sealably inserted within the fuel injector inlets 38 of the manifold body.
To prevent damage to the fuel injectors, typically the first fuel rail will be brought in at an angle in order not to damage the fuel injectors. The second fuel rail is then brought in and the aperture on its bracket 76 is aligned with bracket aperture 73. The above angular movement is critical and more acute when using long injector tip type fuel injectors (so-called extended tip injectors), which limit angular movement of the injectors during installation.
Connecting the fasteners with the connection towers 36 will then complete installation of this portion of the fuel rail system 7 to the vehicle.
It is obvious to those skilled in the art that the upper manifold portion will then be connected with the manifold body 10 (not shown). Since the second fuel rail 58 is not fixably connected to the first fuel rail 46 during initial assembly, the second fuel rail 58 can be brought in angularly in such a manner with the proper assembly of its associated fuel injectors and in a manner which minimizes any chance of damage to a fuel injector due to misalignment during assembly.
Referring to
Assembly to the manifold body 10 will be essentially identical with the exception that connection of the top fuel rail 158 to the air manifold body 10 will also cause insertion of the male connector 153 within the female receptacle 165. Hence, the fuel rails 146, 158 are directly connected to one another, therefore eliminating any need for a fuel inlet directly to the first fuel rail 146. Accordingly, the fuel inlet 148 of the upper fuel injector serves to provide fuel to both fuel rails 146, 158.
The direction of extension of the male connector 163 will be generally parallel to the direction of extension of the cupped outlets 74 so that the assembly of the top fuel rail to the manifold body and the assembly of the associated fuel injectors between the fuel rail and the manifold body will be along the same path as the insertion of the male connecting member 163.
The present invention has been shown in an embodiment of a self dampening rail. However, the fuel rails of the present invention can have a non-stamped material construction and/or a tubular or polygonal cross sectional construction may be utilized. It will be apparent to those skilled in the art of other changes and modifications which can be made without departing from the spirit or scope of the invention as it is encompassed by the following claims.
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