Claims:We Claim

1. A common rail fuel injection system (10), the common rail fuel injection system (10) comprising:
a high-pressure common rail (12), said high-pressure common rail (12) comprising an inlet (14) that is adapted to receive pressurized fuel from a high-pressure fuel pump (16), said high-pressure common rail (12) comprising at least one outlet (18) that is adapted to deliver pressurized fuel to at least one fuel injector (20); characterized in that
said high-pressure common rail (12) including an overflow supply pipe (22), wherein an upstream end of said overflow supply pipe (22) is in flow communication with an overflow outlet port (24) of said high-pressure common rail (12), and wherein a downstream end of said overflow supply pipe (22) is in flow communication with an inlet (26) of a fuel filter (28) to facilitate delivering pressurized fuel from the overflow outlet port (24) of said high-pressure common rail (12) to the inlet (26) of said fuel filter (28).

2. The common rail fuel injection system (10) in accordance with Claim 1, wherein the downstream end of said overflow supply pipe (22) is in flow communication with the inlet (26) of said fuel filter (28) by bypassing the fuel tank (30) to prevent contamination of fuel within the fuel tank (30).
, Description:Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to a fuel injection system, and more specifically to a common rail fuel injection system for supplying fuel to a fuel filter via a low pressure circuit.

Background of the invention
[0002] CN 113586233 A describes a V-shaped high-pressure common rail engine. The V-shaped high-pressure common rail engine comprises a V-shaped air cylinder body, and air cylinder holes symmetrically formed in the two sides of the air cylinder body. Air cylinder covers are arranged at the air cylinder holes. The V-shaped high-pressure common rail engine further comprises a fuel oil system for supporting the engine to operate. An air intake and exhaust system as well as a cooling system, a lubricating system, and a vibration reduction system which play an auxiliary role are also described. The fuel oil system comprises a low-pressure oil pump communicates with a fuel oil tank. The low-pressure oil pump communicates with a fuel filter. The fuel filter communicates with a high-pressure oil pump. The high-pressure oil pump communicates with a plurality of common rail pipes which are connected in series. The common rail pipes communicate with a plurality of oil sprayers. The air inlet and exhaust system comprises symmetrically-arranged superchargers. The air compressor ends of the superchargers communicate with air filters. The other ends of the superchargers communicate with air pipes, and the air pipes communicate with distribution pipes capable of introducing air into the air cylinder body. The engine has the very high strengthening index, low specific mass and high power per liter, and the product has the high cost performance.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a high-pressure common rail in flow communication with an fuel filter in one embodiment of the invention.
Detailed description of the embodiments
[0004] Figure 1 illustrates a high-pressure common rail 12 in flow communication with an fuel filter 28 in one embodiment of the invention. The common rail fuel injection system 10 comprises a high-pressure common rail 12. The high-pressure common rail 12 comprises an inlet 14 that is adapted to receive pressurized fuel from a high-pressure fuel pump 16. The high-pressure common rail 12 comprises at least one outlet 18 that is adapted to deliver pressurized fuel to at least one fuel injector 20. The high-pressure common rail 12 includes an overflow supply pipe 22, wherein an upstream end of the overflow supply pipe 22 is in flow communication with an overflow outlet port 24 of the high-pressure common rail 12. A downstream end of the overflow supply pipe 22 is in flow communication with an inlet 26 of a fuel filter 28 to facilitate delivering pressurized fuel from the overflow outlet port 24 of the high-pressure common rail 12 to the inlet 26 of the fuel filter 28.

[0005] Figure 1 illustrates a high-pressure common rail 12 in flow communication with a fuel filter 28 in one embodiment of the invention. The common rail fuel injection system 10 comprises a high-pressure common rail 12 that is adapted to store pressurized fuel therein. The high-pressure common rail 12 comprises an inlet port 14 that is adapted to receive pressurized fuel from a high-pressure fuel pump 16. The pressurized fuel that is received from the high-pressure fuel pump 16 is therein stored within a storage chamber of the high-pressure common rail 12. The high-pressure common rail 12 comprises at least one outlet 18 that is adapted to deliver pressurized fuel to at least one fuel injector 20.

[0006] In an exemplary embodiment, the high-pressure common rail 12 includes an overflow supply pipe 22. More specifically, an upstream end of the overflow supply pipe 22 is in flow communication with an overflow outlet port 24 of the high-pressure common rail 12. Correspondingly, a downstream end of the overflow supply pipe 22 is in flow communication with an inlet 26 of a fuel filter 28 to facilitate delivering pressurized fuel from the overflow outlet port 24 of the high-pressure common rail 12 to the inlet 26 of the fuel filter 28.

[0007] More specifically, the existing application is that the downstream end of the overflow supply pipe 22 is in flow communication with the fuel tank 30 and delivers fuel that overflows from the high-pressure common rail 12 to the fuel tank 30. However, in the current invention, while the upstream end of the overflow supply pipe 22 is in flow communication with the overflow outlet port 24 of the high-pressure common rail 12, the downstream end of the overflow supply pipe 22 is in flow communication with the inlet 26 of the fuel filter 28. Therefore, the downstream end of the overflow supply pipe 22 supplies pressurized fuel to the inlet 26 of the fuel filter 28 by bypassing the fuel tank 30 to prevent contamination of fuel within the fuel tank 30. In an alternate exemplary embodiment, while the upstream end of the overflow supply pipe 22 is in flow communication with the overflow outlet port 24 of the high-pressure common rail 12, the downstream end of the overflow supply pipe 22 is in flow communication with the inlet of the high-pressure fuel pump 16. Therefore, the downstream end of the overflow supply pipe 22 supplies pressurized fuel to the inlet of the high-pressure fuel pump 16 by bypassing the fuel tank 30 to prevent contamination of fuel within the fuel tank 30.

[0008] A working of the common rail fuel injection system 10 is described as an example. When the high pressure fuel from the high-pressure fuel pump 16 is delivered to an inlet 14 of a high-pressure common rail 12, the received fuel is stored within the high-pressure common rail 12 and therein delivered to a fuel injector 20 for injection into an engine cylinder therein. When excess pressurized fuel from the high-pressure common rail 12 is supplied out of the high-pressure common rail 12 via the overflow supply pipe 22, the upstream end of the overflow supply pipe 22 that is in flow communication with the overflow outlet port 24 of the high-pressure common rail 12 receives the excess pressurized fuel and delivers the excess pressurized fuel to the downstream end of the overflow supply pipe 22. As the downstream end of the overflow supply pipe 22 is in flow communication with an inlet 26 of the fuel filter 28, the pressurized fuel from the downstream end of the overflow supply pipe 22 is delivered from the overflow outlet port 24 of the high-pressure common rail 12 to the inlet 26 of the fuel filter 28.

[0009] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.