Fuel supply apparatus and fuel pressure regulator

A fuel supply apparatus comprising:

• a cover (3) fitted to an opening (2a) of a fuel tank (2), and on which a discharge pipe (7) is disposed;
• a fuel pump (4) for delivering under pressure fuel from said fuel tank (2) to an injector of an engine via said discharge pipe (7);
• a fuel filter (5) for filtering the fuel discharged from said fuel pump (4);
• and
• a fuel pressure regulator (60) for regulating the pressure of the fuel discharged from said fuel pump (4) to a predetermined pressure (Pi);
• wherein said fuel pressure regulator (60) includes:
• a first chamber (62), formed in a case (61), into which fuel discharged from said fuel pump (4) flows, and a second chamber (63), into which the fuel flows via the first chamber (62);
• a fuel control means (64) disposed between said first chamber (62) and said second chamber (63), for limiting fuel flowing from said first chamber (62) into said second chamber (63);
• a pilot valve unit (65) having a passageway for opening to discharge fuel into said fuel tank (2), when the fuel pressure in said second chamber (63) is more than a first set pressure (Pp);
• and
• a main valve unit (66) for opening and closing to discharge fuel into said fuel tank (2), when the fuel pressure in said first chamber (62) is equal to a second set pressure (Pm) between the first set pressure (Pp) and the predetermined pressure (Pi).