Patent Publication Number: US-6990959-B1

Title: Fuel rail delivery system arrangement

Description:
FIELD OF THE INVENTION 
   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. 
   BACKGROUND OF THE INVENTION 
   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. 
   SUMMARY OF THE INVENTION 
   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. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an air fuel delivery system arrangement according to the present invention. 
       FIG. 2  is a side elevational view of the air fuel delivery system arrangement shown in  FIG. 1  slightly tilted and looking generally in an opposite direction from that of  FIG. 1 . 
       FIG. 3  is a side elevational view a fuel rail combination utilized in the air fuel delivery system arrangement shown in  FIGS. 1 and 2 . 
       FIG. 4  is a sectional view of the air fuel delivery system arrangement shown in  FIGS. 1 and 2 . 
       FIG. 5  is a schematic view of a V-type engine utilizing an air fuel delivery system arrangement according to the present invention. 
       FIG. 6  is a top plan view of an alternate preferred embodiment fuel rail combination to that shown in  FIGS. 1–3 . 
       FIG. 7  is a side elevational view of a fuel rail combination to that shown in  FIG. 6 . 
       FIG. 8  is a sectional view of the fuel rail combination shown in  FIG. 7 , taken along line  8 — 8 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1–4 , an air fuel delivery system arrangement  7  is provided. This air fuel delivery system arrangement is preferably used in a V-type reciprocating piston, spark-ignited, internal combustion engine. The air fuel delivery system arrangement  7  is particularly useful in V-type engines wherein the combustion cylinders are inclined from one another 60 degrees or less, which typically has most applications in automotive engines that are transverse mounted in front wheel drive vehicles. 
   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  ( FIG. 4 ). 
   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  FIG. 3 ) fuel rail connection towers  36 . 
   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  ( FIG. 3 ). The hose  50  is connected with a connector  52 . The connector  52  is in turn connected with a hose  54 , which is connected with a fuel inlet  56  associated with a second fuel rail  58 . Fuel is delivered to the connector  52  via a hose  60 . The fuel rail combination  44  is of the non-recirculating type. Fuel delivered to the fuel inlets  48 ,  56  does not recirculate back to a fuel tank or pump reservoir, but instead exits out of the fuel rails as therein delivered through the fuel injectors. 
   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  FIG. 4 , brackets  73 ,  76  are on the right side. A virtually identical connection arrangement connects the first  46  and second  58  fuel rails on their left side with a similar connection tower  36  (not shown) at a location toward the blind end of the fuel rails. 
   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  FIGS. 6–8 , an alternative embodiment fuel rail combination  144  is provided. Fuel rail combination  144  has a first fuel rail  146  and a second fuel rail  158 . The fuel rails  146 ,  158  have cupped outlets  72 ,  74  essentially identical to those described. Additionally, the fuel rails  146 ,  158  have main bodies generally similar to those aforedescribed. A major difference in the fuel rails  146 ,  158  is that the second fuel rail  158  has a male fluid connector projection  163  which sealably can be inserted through a female receptacle  165  provided in the lower first fuel rail  146 . 
   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.