Fuel feeding system for internal combustion engine

A fuel feeding system for an internal combustion engine, comprising:

• a low-pressure fuel pump arranged between a fuel injection valve (1) disposed in said internal combustion engine and a fuel tank (2);
• a fuel line (3) constituted as a recirculating circuit which extends from said fuel tank (2) to said fuel injection valve (1) and further returns from said fuel injection valve (1) to said fuel tank (2);
• a high-pressure fuel pump (5) arranged in said fuel line (3) between said low-pressure fuel pump (4) and said fuel injection valve (1) and driven by said internal combustion engine;
• a high-pressure control unit (10) arranged in said fuel line on a downstream side of said high-pressure fuel pump (5) for controlling to a first controlled pressure a pressure of fuel delivered from said high-pressure fuel pump (5);
• a fuel pressure control valve (14) arranged in a bypass passage (13), which extends from an upstream side to a downstream side of said high-pressure control unit (10), for opening or closing said bypass passage (13) in accordance with a state of operation of said internal combustion engine;
• a low-pressure control unit (9) for controlling, upon opening said bypass passage (13) by said fuel pressure control valve (14), a fuel pressure in said fuel line on an upstream side of said bypass passage (13) to a second controlled pressure lower than said first controlled pressure by said high-pressure control unit (10);
• a drive duration setting unit (34) for setting a first drive duration as a drive duration of said fuel injection valve (1) corresponding to said first controlled pressure and a second drive duration as a drive duration of said fuel injection valve (1) corresponding to said second controlled pressure, said second drive duration being longer than said first drive duration;
• a fault detection unit (31) for detecting a fault in said fuel pressure control valve (14) and a resulting restriction of an opening of said bypass passage (13);
• and
• a drive duration changing unit (32) for changing, upon detection of a fault by said fault detection unit (31), a drive duration of said fuel injection valve (1) to a third drive duration which falls between said first drive duration and said second drive duration.

A fuel feeding system for an internal combustion engine, comprising:

• a low-pressure fuel pump (4) arranged between a fuel injection valve (1) disposed in said internal combustion engine and a fuel tank (3);
• a fuel line (3) constituted as a recirculating circuit which extends from said fuel tank (2) to said fuel injection valve (1) and further returns from said fuel injection valve (1) to said fuel tank (2);
• a high-pressure fuel pump (5) arranged in said fuel line (3) between said low-pressure fuel pump (4) and said fuel injection valve (1) and driven by said internal combustion engine;
• a revolution speed sensor (33) for detecting a revolution speed of said high-pressure fuel pump (5) or of a rotary member rotating in synchronization with said high-pressure fuel pump (5);
• a fuel pressure determination unit for directly or indirectly determining a fuel pressure in said fuel line on a downstream side of said high-pressure fuel pump (5) in accordance with a value substantially correlated to said fuel pressure in said fuel line on said downstream side of said high-pressure fuel pump (5);
• a drive duration setting unit (34) for setting a drive duration of said fuel injection valve on a basis of results of a determination by said fuel pressure determination unit;
• a fault detection unit (31) for detecting a fault in at least said fuel pressure determination unit;
• and
• a drive duration changing unit (32) for changing, upon detection of a fault by said fault detection unit (31), a drive duration of said fuel injection valve (1) on a basis of results of a detection by said revolution speed sensor (33).