Abstract:
There is provided a hydraulic fuel system having an integrated and internally mounted oil circuit for providing high pressure in a hydraulically operated electronically controlled fuel injector fuel system. There is provide an internally mounted high pressure pump in a pump housing in the crankcase and connected to internally routed high pressure lines that deliver the oil to high pressure oil rails. There is provide an integrated low pressure oil reservoir in the crank case that comprises a low pressure oil cooler and reservoir. The oil cooler is preferably immersed inside the low pressure oil reservoir to optimize available engine space and improve heat transfer. There is also provided a high pressure pump filter that covers a high pressure pump inlet feed passage to prevent debris from passing into the high pressure oil pump and other components on the high pressure oil circuit.

Description:
This patent application claims the benefit of Provisional U.S. Patent application Ser. No. 60/177,857 filed on Jan. 24, 2000. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to hydraulic fuel systems for internal combustion engines. More particularly, this invention relates to hydraulic fuel systems for diesel engines with hydraulically activated electronically controlled unit injection. 
     BACKGROUND OF THE INVENTION 
     Many diesel engines use hydraulically activated electronically controlled unit injection (HEUI) fuel systems to improve engine performance. HEUI fuel systems, also referred to as hydraulic fuel systems, require high-pressure oil to operate the fuel injectors. In particular, the HEUI system employs high pressure lube oil acting on an intensifier piston in the top of each fuel injector to drive down a fuel plunger and thereby eject fuel. Existing HEUI fuel systems, typically have a high pressure lube oil circuit and a low pressure oil circuit and a high pressure oil pump cooperatively between them. 
     Existing HEUI fuel systems typically have various components mounted externally to the engine, and in particular to the engine crank case. The high pressure oil circuit, for example, has an externally mounted high pressure pump and externally routed high pressure oil lines that deliver high pressure oil to high pressure rails or reservoirs. Also, the low pressure oil circuit typically has a low pressure oil cooler that is also mounted externally to the engine crankcase. Further, the low pressure oil cooler and a low pressure oil reservoir, which feeds low pressure oil to the high pressure pump, are typically separate components in existing hydraulic fuel systems. The location, relative to the engine, of these various components results in a large number of components needed to provide the high pressure oil in existing HEUI fuel system. Moreover, the externally mounted nature of these components typically increases the size of the engine compartment space required by engines using the HEUI fuel system. 
     In addition, the externally mounted and separate component have a greater probability of developing oil leaks and adversely impacting the engine performance and the environment outside the engine. The externally mounted and separate hydraulic fuel system components also tend to lead to higher engine manufacturing time, costs and complexity due to a greater number of components being mounted to the engine. 
     Accordingly, there is a need for a hydraulic fuel system, which provides high pressure oil, with reduced space requirements while minimizing the impact of oil leaks in the hydraulic fuel system oil circuit. 
     SUMMARY OF THE INVENTION 
     The present invention provides a hydraulic fuel system, or hydraulically-operated electronically controlled fuel injector system, having an integrated and internally mounted oil circuit for providing appropriate high pressure required in the HEUI fuel system. There is provided an internally mounted high pressure pump connected to internally routed high pressure lines or tubes that deliver oil from the high pressure pump to high pressure oil reservoirs or rails. The high pressure pump is internally mounted in a high pressure pump housing in the crankcase and the high pressure oil lines are internal to the engine. The high pressure pump housing is positioned in a rear top portion of the crank case in the V-portion of a V-type engine. The high pressure oil lines comprise flexible tube sections and other components to reduce vibrational wear. There is also provide an integrated low pressure oil reservoir which is positioned in a front top portion of the crank case in the V-portion of the engine. The integrated low pressure oil reservoir comprises a low pressure oil cooler and a low pressure oil. The oil cooler or heat exchanger is immersed inside the low pressure oil reservoir to reduce space and improve heat transfer. The integrated low pressure reservoir also has a high pressure pump filter that covers a high pressure pump feed passage that supplies low pressure oil to the high pressure oil pump. The filter prevents debris from passing into the high pressure oil pump and other components on the high pressure oil circuit of the hydraulic fuel system. 
     The hydraulically-operated electronically controlled fuel injector (HEUI) system 
     for an internal combustion engine for actuating a fuel injector comprises a controller able to receive an actuating fluid pressure measurement from an ICP sensor; an IPR valve; at least one high pressure actuating fluid reservoir; an integrated low pressure fluid reservoir; a rear gear driven high pressure pump disposed in a high pressure pump housing and operatively connected to the integrated low pressure fluid reservoir; and an internally disposed high pressure fluid line operatively connecting the high pressure pump and the at least one high pressure actuating fluid reservoir, whereby the controller selectively modifies pressure in the high pressure fluid line via selective actuation of the IPR valve to obtain a desired pressure in the at least one high pressure actuating fluid reservoir. 
     Additionally, the high pressure pump housing further comprises a high pressure pump cover and a high pressure pump mounting in a rear top crank case area. And, the high pressure pump housing and the integrated low pressure fluid reservoir are disposed between a first and a second cylinder head. The HEUI system also has an integrated low pressure fluid reservoir comprising a low pressure fluid cooler and a low pressure fluid housing in a front top crank case area, a high pressure pump filter and a high pressure pump feed passage connected to the high pressure pump. 
     The high pressure fluid line further comprises a high pressure discharge tube attached to the high pressure pump; a branch tube section attached to the high pressure discharge tube; a rigid tube section attached to the branch tube section; a flexible tube section attached to the rigid tube section; and a high pressure check valve attached between the flexible tube section and the high pressure actuating fluid reservoir. 
     The following drawings and description set forth additional advantages and benefits of the invention. More advantages and benefits will be obvious from the description and may be learned by practice of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention may be better understood when read in connection with the accompanying drawings, of which: 
     FIG. 1 shows a schematic view of a hydraulic fuel system according to the present invention; 
     FIG. 2 shows a perspective view of a low pressure oil circuit of the hydraulic fuel system shown in FIG. 1 according to the present invention; 
     FIG. 3 shows a top view of an integrated low pressure reservoir cover mounted on a top front portion of a crank case according to the present invention; 
     FIG. 4 shows a perspective view of a low pressure oil reservoir in the front top portion of the crank case with an installed high pressure pump screen filter according to the present invention; 
     FIG. 5 shows a top view of the high pressure pump filter shown in FIG. 4; 
     FIGS. 6 shows a front view of the high pressure pump filter shown in FIG. 5; 
     FIG. 7 shows a section end view of the high pressure pump filter along the section line A—A shown in FIG.  6 . 
     FIG. 8 shows a perspective and exploded view of a high pressure oil circuit of the hydraulic fuel system shown in FIG. 1 according to the present invention; 
     FIG. 9 shows rear, top and side perspective views of an operatively connected high pressure pump and a high pressure oil line assembly of the high pressure oil circuit shown in FIG. 8 according to the present invention; 
     FIG. 10A shows a perspective view of the high pressure oil line assembly shown in FIG. 9 according to the present invention; 
     FIG. 10B shows a perspective view of various component lines comprising the high pressure oil line assembly shown in FIG. 10A; 
     FIG. 11A shows a perspective view of a high pressure pump cover shown in FIG. 8 according to the present invention; 
     FIG. 11B shows a section view of the high pressure pump cover along the section line B—B shown in FIG. 11A; 
     FIG. 12 shows a perspective bottom view of a rear branch tube for the hydraulic fuel system shown in FIG. 9; 
     FIG. 13 shows a perspective view of a high pressure pump housing, and a portion of the high pressure line assembly of FIG. 10A installed in a rear portion of a crack case according to the present invention. 
     FIG. 14 shows a top view of a high pressure pump inlet seal in the high pressure pump housing shown in FIG. 13 according to the present invention; 
     FIG. 15 shows a rear perspective view of the high pressure pump installed in the high pressure pump housing show in FIG. 13; 
     FIG. 16 shows a perspective view of an O-ring discharge seal for the high pressure pump shown in FIG. 15 according to the present invention; 
     FIG. 17 shows a perspective view of the high pressure pump operatively connected to the high pressure oil line shown in FIG. 15 according to the present invention; 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a schematic view of a hydraulic fuel system  100  for an internal combustion engine (not shown) according to the present invention. FIG. 1 preferably represents a diesel engine having a V-type configuration, a first and second cylinder head  130  and  132 , six cylinders, and hydraulically activated electronically controlled unit fuel injection. However, those of skill in the art will readily recognize that the hydraulic fuel system  100  of the present invention may be applied to other types of internal combustion engines including ignition engines, in-line configurations, and other numbers of cylinders. 
     The hydraulic fuel system  100  has a low pressure oil circuit  200  (shown in FIG. 2) interconnected with a high pressure oil circuit  300  (shown in FIG. 8) to thereby deliver high pressure actuating fluid to high pressure reservoirs  150  and  152 . The high pressure fluid used in FIG. 1 is preferably engine lubrication oil. However, those of skill will readily recognize that other actuation fluids may be used in the hydraulic fuel system  100 . The low pressure oil circuit  200  operates at oil pressures below 100 psi, and preferably about 50 psi. The high pressure circuit  800  can operates at oil pressures up to 6,000 psi. Other oil pressures including different oil pressures for different parts of the hydraulic fuel system may be used depending on a particular engine application. 
     In operation, the hydraulic actuation fluid or engine oil gathers in an engine oil sump or oil pan  105 . The sump  105  is preferably located at the lowest part of the engine so gravity returns used oil for further circulation through the engine and hydraulic fuel system  100 . A low-pressure pump  110 , e.g., a typical gerotor pump, supplies oil from the oil sump  105  through an oil cooler  112  and an oil filter  115  into a low pressure reservoir  117 . In a preferred embodiment, the low pressure oil cooler  112 , the oil filter  115 , and the low pressure oil reservoir  117  comprise part of the integral low pressure oil reservoir  120 . Although, the engine oil filter  115  is shown as part of the integrated low pressure oil reservoir  120 , it  115  may also be a separately attached component. Low pressure oil can then be provided to different parts of the engine for lubrication. For example to lubricate the first and second cylinder heads  130  and  132 , the turbocharger  135 , and the like. Low pressure oil is also fed from the low pressure oil reservoir  117  to a typical high pressure pump  140 . 
     The high pressure pump  140  discharges high pressure oil in a high pressure oil delivery line  143 , which is operatively connected to an injection pressure regulator (IPR) valve  145  and a first and second high pressure oil reservoir  150  and  152 . Typical IPR valves  145  have a mechanical relief valve section built in that operates if the electronically controlled valve fails to a closed position, thereby preventing overpressure damage to the system. In the preferred embodiment, there is a first and second check valve  160   162  between the high pressure oil line  143  and the first and second high pressure oil reservoirs  150  and  152 . The high pressure oil reservoirs  150  and  152  are also typically knows as high pressure oil rails. The high pressure oil in the first and second high pressure oil reservoirs  150  and  152  is then selective and appropriately applied to the fuel injectors  155 . 
     The delivery of high pressure oil is controller by the IPR valve  145  which is in turn controlled by a controller (not show), typically an electronic control module (ECM). The ECM appropriately operates the IPR valve  145  to open and bleed off, or dump, a portion of the high pressure oil, ultimately back to the engine oil sump  105 , based upon high pressure oil measurements received from an injection control pressure (ICP) and other engine parameters. Other engine parameters can include throttle position, oil temperature, low oil pressure measurement, etc. In this manner, the ECM operates the IPR valve  145  to control pressure in the high pressure oil circuit  800  and thereby obtain or maintain a desired pressure in the high pressure line  143  and in the high pressure oil reservoirs  150  and  152 . 
     When the ECM determines that fuel will be injected by a specific injector, based on various received engine parameter measurements or signals, the ECM will send a fuel delivery control signal to an injector drive module (not shown). The injector drive module will actuate a poppet valve (not shown) that then allows the high pressure oil from the high pressure oil reservoirs  150  and  152  to actuate an injector intensifier piston (not shown). The high pressure oil acting on the intensifier piston will actuate a fuel plunger which will increase the fuel pressure in an injector needle (not shown). When the fuel pressure is sufficient, it will lift the injector needle of its seat against its spring force (popping pressure) and thereby begin fuel injection into a corresponding combustion chamber (not shown). 
     FIG. 2 shows a perspective view of a low pressure (LP) oil circuit  200  of the hydraulic fuel system  100  according to an embodiment of the present invention. The low pressure oil circuit  200  provides low pressure oil to the engine and to the high pressure pump  140 . There is shown a low pressure oil pump or gerotor pump  110  which draws oil from the engine oil sump or oil pan  105  (shown in FIG.  1 ). The gerotor or oil pump  110  supplies low pressure oil to the integrated low pressure oil reservoir  120  via a low pressure pump discharge passage  205  in the crank case (not shown). The low pressure oil is pumped upward to the top of the crank case where it goes into an integrated low pressure (LP) reservoir cover  300  (shown in FIG.  3 ). The integrated LP reservoir cover  300  is preferably made of cast aluminum, though other materials may be substituted, and preferably also holds a low pressure oil cooler  112 . The oil then passes through the low pressure oil cooler  112  and into and out of onto a oil filter assembly  115  (shown in FIG.  1 ). The low pressure oil cooler  112  is situated under the integrated LP reservoir cover  300  and is disposed in a low pressure reservoir  117  (shown in FIGS.  1  and  4 ). Thus, the low pressure oil cooler  112  is surrounded by the oil in the low pressure reservoir  117 . 
     The low pressure oil then goes on to lubricate the engine via appropriate passages  210  in the crank case, and to fill the low pressure oil reservoir  117  that is formed in the top front area  410  of the crank case. There is also shown a high pressure pump feed passage  215  that feeds low pressure oil via the low pressure oil reservoir  117  to the high pressure pump  140 . The high pressure pump feed passage  215  is preferably comprised of a horizontal passage  217  in the crank case and a vertical passage  219  (also shown in FIGS. 13 and 14) in a rear top portion  1305  (shown in FIG. 13) of the crank case that connects to a pressure pump inlet (not shown). 
     In a preferred embodiment, the integral low pressure oil reservoir  120  comprises the low pressure oil cooler  112  and the low pressure oil reservoir  117 . The integrated low pressure oil reservoir  120  can further comprise the high pressure pump feed passage  215  and a high pressure pump filter  420  (shown in FIG.  4 ). Also, the engine oil filter  115  can be part of the integrated low pressure oil reservoir  120  or it  115  may be a separately component that cooperatively attached to the integrated LP oil reservoir  120 . 
     FIG. 3 shows a top view of the integrated low pressure reservoir cover  300  mounted on a top front portion  410  (shown in FIG. 4) of a crank case and thereby enclosing the low pressure oil cooler  117  (shown in FIG. 4) to form the integrated low pressure oil cooler  120  that is part of the low pressure circuit  200 . Moreover, the integrated low pressure oil cooler cover  300  can further comprise a bypass valve configuration  305  and EGR tube configuration  310 . 
     FIG. 4 shows a perspective view of the low pressure oil reservoir  117  preferably formed as part of the crank case and situated in the front top  410  portion of the crank case. In addition, when the hydraulic fuel system of the present invention is used in a V-type engine application, the low pressure oil reservoir  117  is preferably situated in the middle V-configuration between the first and second cylinder head mountings  1310  and  1320  on the crank case (shown in FIG.  13 ). During engine start up, before the system develops pressure, the low pressure reservoir  117  provides a gravity feed to the high pressure pump  140  through a screen filter  420 . Once the engine is in operation, the low pressure oil reservoir  117  is at lube pressure system (approximately in the range of 15 to 50 psi depending on engine speed). This lube pressure maintains a low pressure oil feed to the high pressure pump  140  during engine operation. Further, the low pressure reservoir  117  provides oil that will keep the high pressure rails  150  and  152  filled when the engine is not operating, since oil will cool and contract in the high pressure rails  150  and  152  rails and causes a void if not replenished. The oil from the low pressure reservoir  117  is fed by gravity from the reservoir to the high pressure reservoirs  150  and  152  through a check valve (not shown) in the high pressure pump  140 , that is seated (closed) when the engine and pump are in operation. 
     FIG. 4 further shows a high pressure pump filter  420  that filters the low pressure oil in the bottom of the low pressure oil reservoir  117 . The high pressure pump filter  420  prevents debris from entering the high pressure pump passage  215  (shown in FIG. 2) which could lead to malfunction of components in the high pressure oil circuit  800  (shown in FIG.  8 ). The high pressure pump filter  420  is preferably a screen type filter, or strainer filter of at least  150  microns in size. 
     FIG. 5 shows a top view of the high pressure pump filter  420  shown mounted inside and at the bottom of the low pressure reservoir  117  shown in FIG.  4 . Low presure oil is fed from the low pressure reservoir  117  through the screen filter  420 , which prevents debris from flowing into the high pressure pump feed passage  215 . The filter screen  420  has a support frame  510  forming several openings for the low pressure oil to pass. While six openings are shown, one or other numbers of openings may be used. Each opening is covered by mesh  505 , which is sized to collect debris that may damage the high pressure oil circuit  800  of the hydraulic fuel system  100  while minimizing the pressure drop across the filter  420 . The high pressure pump filter  420  is preferably a  150  micron screen type filter. However, those of skill in the art will recognize that filter  420  could also be large than  150  micron screen filter depending on particular engine applications, e.g., a larger screen filter for engine cold starting. Also, the support frame and mesh are made of plastic although other suitable materials may be used. 
     A rubber handle bumper  520  is connected to the support frame  510  by posts  515 . When assembled, low pressure oil cooler  112  of the integrated low pressure oil reservoir  120  presses against the rubber handle bumper  520 , which operatively flexes or contracts to hold the screen filter  420  in place. The screen filter  420  may also be used without the rubber bumper  520 , in which case the oil flow would keep the screen filter  420  in place. The rubber handle bumper  520  is preferably made rubber or other elastomeric material. 
     FIGS. 6 shows a front view of the high pressure pump screen filter  420  shown in FIG.  5 . FIG. 7 shows a section end view of the high pressure pump filter  420  along the section line A—A shown in FIG.  6 . 
     FIG. 8 shows a perspective and exploded view of a high pressure oil circuit  800  of the hydraulically-operated electronically controlled fuel injector system  100 , or hydraulic fuel system, shown in FIG.  1 . Generally, a controller or ECM, after receiving and processing a pressure measurement in the high pressure oil line  143  from an injection control pressure (ICP) sensor (not shown). The ECM will then selectively modify pressure in the high pressure oil circuit  800  via selective actuation of an IPR valve  145  to obtain a desired pressure in the high pressure oil circuit  800 . The ICP sensor is preferably mounted adjacent to the IPR valve  145  to monitor the high pressure line  143  oil pressure. The high pressure pump  140  and IPR valve  145  will cooperatively maintain appropriate high oil pressures in the high pressure oil reservoirs  150  and  152 . The IPR valve typical working pressure is about 28 Mpa or 4060 psi. The high pressure oil circuit  800  provides high pressure actuating fluid, or high pressure oil, to the high pressure oil reservoirs  150  and  152  which in turn appropriately interact with the unit injectors  155  to inject fuel into a corresponding combustion chamber via appropriate actuation from a controller, for example an electronic control module (ECM) or microprocessor (not shown). The operation of the high pressure oil circuit  800  is described in FIG.  1 . 
     FIG. 8 shows a high pressure oil circuit comprised of a plurality of fuel injectors  155  operatively connected to a first and second high pressure oil reservoir  150  and  152 . There is a first and second check valve  160  and  162  operatively connected between the first and second high pressure reservoirs  150  and  152  and a high pressure oil line  143 . The high pressure oil line  143  is connected to the high pressure pump  140 . There is also shown a high pressure pump cover  805  and pump cover seal  807  which will enclose the high pressure pump  140  in a high pressure pump housing  1300  (show in FIG. 13) located in a top rear portion  1305  (shown in FIG. 13) of the crank case. Also shown is a high pressure pump actuation gear  810  that drives the high pressure pump  140 . The high pressure pump  810  is connected to a rear gear assembly  1505  (shown in FIG. 15) that will drive the high pressure pump  140 . 
     FIG. 8 also shows that the high pressure oil line  143  is preferably comprised of a high pressure discharge tube  815  that attaches to the high pressure pump  140 , a branch tube section  820  that attaches to the high pressure discharge tube  815 , a first and second rigid tube section  850  and  852  that attaches to the branch tube section  820 , a first and second flexible tube section  860  and  862  that attaches to a corresponding first and rigid tube section  850  and  852 , and a first and second high pressure check valve  160  and  162  that respectively is attaches between corresponding first and second flexible tube sections  860  and  862  and the respective high pressure actuating oil reservoirs  150  and  152 . 
     The high pressure discharge tube  815  is further preferably comprised of an injection pressure regulator (IPR) valve tube section  817  and a high pressure discharge tube section  819 . Also, the branch discharge tube  820  further comprises a branch section  822 , a tube support section  824 , a first branch  830  attached to the branch section  822  at a first branch end  831  and having a first branch coupler  840  attached to a first branch distal end  839  and able to receive the first rigid tube section  850 . The branch discharge tube  820  further comprises a second branch  832  attached to the branch section  822  at a second branch end  833  and having a second branch coupler  842  attached to a second branch distal end  841  and able to receive the second rigid tube section  852 . 
     The high pressure oil line  143  has been described as preferably comprised of various interconnected component tubes, passages, sections and couplers. However, those of skill in the art will recognize that the high pressure oil line  143  could be comprised of more or less parts having rigid or flexible configurations. Also, the high pressure oil line  143  is preferably comprised of a plurality of sections that used snap fittings or threaded connections to connect to each other. However, other means can be used to connect the various sections, for example brazing or welding sections together. 
     Furthermore, the various first and second components comprising the high pressure oil circuit  800  are described because the preferred embodiment relates to a diesel engine which has a first and second cylinder head  1310  and  1320  mounting on the crank case (shown in FIG. 13) in a V-type configuration. This requires that the high pressure oil line  143  be split to feed the first and second high pressure oil reservoirs  150  and  152  in the cylinder heads  130  and  132  (not shown). Those of skill in the art, however, will readily recognize that other engine configurations would result in a modified high pressure line  143 . The high pressure reservoirs  150  provide oil through a check valve  160  to a fuel injector  155  for each cylinder (not shown). Further, while first and second check valves  160  and  162  are shown, other devices may used to control the creation Helmholtz resonance of pressure waves. 
     FIG. 9 shows rear, top and side perspective views of an operatively connected high pressure pump  140  and a high pressure oil line or assembly  143  of the high pressure oil circuit  800  shown in FIG.  8 . There is shown a high pressure pump  140  which is preferably disposed in a high pressure pump housing  1300  (show in FIG. 13) located in a top rear portion  1305  (shown in FIG. 13) of the crank case. A high pressure discharge tube  815  attaches to the high pressure pump  140 . The high pressure discharge tube  815  is further preferably comprised of an injection pressure regulator (IPR) valve tube section or IPR port  817  and a high pressure discharge tube section  819 . The discharge tube section  819  is preferably configured to travel around and down from the high pressure pump  140  and then toward the rear of the high pressure pump  140  (also shown in FIG.  17 ). 
     The high pressure discharge tube section  819  then cooperatively attaches to the branch section  822  of the branch tube  820  of the high pressure oil line  143  towards the rear of the crank case (shown in FIG.  17 ). The branch discharge tube  820  also comprises a tube support section  824  (shown in FIG.  12 ), a first branch  830  attached between the branch section  822  and a first branch coupler  840 . The first branch  830  is preferably configured to travel internally in the crank case into a first cylinder head mounting  1310  (shown in FIG.  13 ). The first branch  830  preferably travels internally in the first cylinder head mounting  1310  to a point between two rear right piston bores  1325  and  1330  (shown in FIG.  13 ). The first branch coupler  840  (also shown in FIG. 13) is attached to the crank case, preferably via a bolt, and configured to receive the first rigid tube section  850 . 
     The first rigid tube section  850  then preferably travels, still internally, up through the first cylinder head mounting  1310  (shown in FIG.  13 ), through a first cylinder head  130  (not physically shown), through a first rocker carrier (not shown) and then attaches to a first flexible a first flexible tube section  860 . The first flexible tube section  860  is then connected to a first high pressure check valve  160  (shown in FIG. 1) that respectively attaches this side of the high pressure oil line  143  to the a corresponding high pressure actuating oil reservoir  150  (shown in FIGS.  1  and  8 ). 
     The branch discharge tube  820  also comprises a second branch  832  attached between the branch section  822  and a second branch coupler  842 . The second branch  832  is preferably configured to also travel internally in the crank case into a second cylinder head mounting  1320  (shown in FIGS. 13,  15  and  17 ). The second branch  832  preferably travels internally in the second cylinder head mounting  1320  to a point between the two rear left piston bores  1525  and  1530  (shown in FIG.  15 ). The second branch coupler  842  (shown in FIG. 13) is attached to the crank case, preferably via a bolt (not shown), and configured to receive the second rigid tube section  852 . 
     The second rigid tube section  852  then preferably travels, internally, up through the second cylinder head mounting  1310  (shown in FIGS. 13,  15 , and  17 ), through the second cylinder head  132  (not physically shown), through a second rocker carrier (not shown) and then attaches to a second flexible tube section  862 . The second flexible tube section  862  is then connected to the second high pressure check valve  162  (shown in FIG. 1) that respectively attaches this second side of the high pressure oil line  143  to the a corresponding high pressure actuating oil reservoir  152  (shown in FIGS.  1  and  8 ). 
     Thus, the high pressure oil assembly  143  preferably internally conveys or delivers high pressure oil from the high pressure pump  140 , cooperatively with the IPR valve  145  to the first and second high pressure oil reservoirs  150  and  152  (shown in FIGS.  1  and  8 ). The high pressure oil line  143  is preferably made from light weight steel material, although other suitable materials may be used. As mentioned previously, the high pressure oil line  143  is internal to the engine, and more specifically to the crank case cylinder head mountings  1310  and  1320  and cylinder heads  130  and  132 . This will reduce the space required by the high pressure oil circuit  800  and keep substantially all high pressure oil leaks inside the engine. In addition, the flexible tube sections  860  and  862  preferably reduce vibrational wear of the high pressure oil line  143  encountered during normal engine operation. The flexible sections are preferably made of wire reinforced hose although any suitable material may be used. To further reduce vibrational wear, the high pressure line  143  further uses elastomeric isolators, or rubber grommets  1205  (shown in FIG. 12) and other vibration control connections to the crank case. 
     FIG. 10A shows a perspective view of the high pressure oil line  143  as preferably assembled and shown without the high pressure pump of FIG.  9 . FIG. 10B shows a perspective view of the various high pressure oil line component or sections preferably comprising the high pressure oil line  143  assembly shown in FIG.  10 A. There is shown a high pressure discharge tube  815 , a branch tube section  820  that attaches to the high pressure discharge tube  815  with a first and second branch coupler  840  and  842 , a first and second rigid tube section  850  and  852  that attaches to the first and second branch couplers  840  and  842 , a first and second flexible tube section  860  and  862  that attaches to a corresponding first and rigid tube section  850  and  852 . 
     FIG. 11 shows a perspective view of the high pressure pump cover  805  shown in FIG. 8 according to the present invention. FIG. 1B further shows a section view of the high pressure pump cover along the section line B—B shown in FIG.  11 A. In a preferred embodiment, the high pressure pump  805  comprises an IPR valve mounting  1105  configured to accept the IPR valve  145  (show in FIG. 8) and an ICP mounting  1110  able to accept and injection control pressure (ICP) sensor (not shown). The high pressure pump cover further  805  comprises a pump cover fluid passage  1115  with one end  1120  shown capped of. The high pressure fluid passage  1115  that preferably extends horizontally back toward a center area  1130  of the high pressure pump cover  805 . The IPR valve mounting  1105  and ICP mountings  1110  cooperatively connect with the high pressure fluid passage  1115 . At the center area  1130  the high pressure fluid passage  1115  turns and travels downward in a vertical direction where it will have a second high pressure fluid passage  1115  opening  1135 . The second pump cover  805  opening  1135  will cooperatively accept an injection pressure regulator (IPR) valve tube section, or IPR port  817 , which contains high pressure oil and is part of the high pressure discharge tube  815  in the high pressure oil line  143  (shown in FIG.  8 ). 
     FIG. 12 shows a perspective bottom view of the tube support section  824  (also show in FIG. 8) which is preferably attached to the underside of the branch section  822  of the branch tube  820  (shown in FIG.  8 ). The tube support section  824  is preferably located between the first and second branch  830  and  832 . The tube support section  824  is preferably a metal and rubber combination configured to support the high pressure oil line  143  to the crank case, to provide some “give” for tolerances between parts in the crank case, and to reduce vibrational wear of the high pressure oil circuit  800  during engine operation. The rubber portion  1205  of the tube support section  824  is preferably an elastomeric isolator, or rubber grommet, or other vibration control connection to the crank case. 
     FIG. 13 shows a perspective view of the internal high pressure pump housing  1300  in the rear portion  1305  of the crack case. The high pressure pump mounting  1300  is preferably located between a first and second cylinder head  1310  and  1320  mounting on the crank case in an engine with a V-type configuration. A high pressure pump cover  805  (shown in FIGS. 11A &amp; B) will operatively cover the high pressure pump  140  which will be disposed in the high pressure pump housing  1300  located in a top rear portion  1305  (shown in FIG. 13) of the crank case. 
     There is also shown a branch tube section  820  of the high pressure line  143  installed in the first and second cylinder head  1310  and  1320  mountings. The first and second branches  830  and  832  preferably travel internally in the first and second cylinder head mountings  1310  and  1320  to a point between two rear right and left piston bores  1325  &amp;  1330 , and  1525  &amp;  1530  (shown in FIG.  15 ). There is also shown the first and second branch couplers  840  and  842  attached to the crank case, preferably via a bolt, and configured to receive the first and second rigid tube sections  850  and  852 . When attached, the first and second rigid tube sections  850  and  852  (shown in FIG. 9) travel internally up through the first and second cylinder head mountings  1310  and  1320 , through the first and second cylinder heads  130  and  132  (not physically shown), through a first and second rocker carrier (not shown) and then attaches to a first and second flexible tube section  860  and  862 . 
     There is also partially shown the low pressure oil reservoir  117  (shown in FIG. 4) preferably formed as part of the crank case and situated in the front top  410  portion of the crank case (shown in FIG.  4 ), as well as the high pressure pump filter  420  that filters the low pressure oil that enters the high pressure pump feed passage  215  (shown in FIG.  2 ). Last, there is shown the vertical passage  219  that feeds low pressure oil to the high pressure pump  140 , and a crank case rear gear assembly  1505  (also shown in FIG. 15) that will drive the high pressure pump  140 . FIG. 14 shows close-up top view of a high pressure pump inlet seal  1405  in the vertical passage  219  that feeds low pressure oil to the high pressure pump  140 . 
     FIG. 15 shows a perspective view of the high pressure pump  140  installed in the high pressure pump housing  1300  in the rear top portion  1305  of the crank case shown in FIG.  13 . There is also shown a high pressure discharge tube  815  attached to the branch tube section  820  of the high pressure line  143  which is installed in the first and second cylinder head  1310  and  1320  mountings (described in FIG.  13 ). The high pressure discharge tube  815  will be attached to a top portion  1535  of the high pressure pump  140  (shown in FIG.  17 ). The arrangement of the high pressure discharge tube  815  shows that the high pressure discharge pump  140  can be easily removed and installed without dismantling the high pressure line  143 . This is the case since the high pressure discharge tube  815  can rotate away and toward the high pressure pump  140  as necessary. 
     There is also shown more clearly the branch tube section  820  of the high pressure line  143  installed in the second cylinder head  1320  mountings. The second branch  832  preferably travels internally in the second cylinder head mounting  1320  to a point between two rear left piston bores  1525  and  1530 . FIG. 15 also shows a high pressure pump actuation gear  810  that drives the high pressure pump  140 , and the rear gear assembly  1505  which in turn drives the high pressure pump rear gear  810 . FIG. 16 shows a close up view of the an O-ring discharge seal  1605  in the top portion  1535  of the high pressure pump shown in FIG.  15 . 
     FIG. 17 shows a perspective view of the high pressure pump  140  installed in the high pressure pump housing  1300  in the rear top portion  1305  of the crank case shown in FIG.  15 . There is also shown a high pressure discharge tube  815  operatively attached to the 
     high pressure discharge tube  815  and the branch tube section  820  of the high pressure line  143 . There is shown the IPR valve tube section or port  817  which is part of the high pressure discharge tube  815 . Also, the branch tube section  820  of the high pressure line  143  installed in the second cylinder head  1320  mounting is more clearly shown. The second branch  832  preferably travels internally in the second cylinder head mounting  1320  to a point between two rear left piston bores  1525  and  1530 . Last, FIG. 17 shows the operatively connected high pressure pump actuation gear  810  and rear gear assembly  1505 . 
     The invention has been described and illustrated with respect to certain preferred embodiments by way of example only. Those skilled in that art will recognize that the preferred embodiments may be altered or amended without departing from the true spirit and scope of the invention. Therefore, the invention is not limited to the specific details, representative devices, and illustrated examples in this description. The present invention is limited only by the following claims and equivalents.