Abstract:
A fuel pressure regulator (1,201) for a compression ignition diesel engine. The regulator (1, 201) comprises a bore (5,205) within which is located a valve member (3,203) that is moveable from a non-regulating position to a regulating position. In a non-regulating position a first end (11,211) of the bore (5,205) is closed. In a regulating position the first end of the bore (5,205) is open. A control fuel line connection (8,208) is positioned at a second end (9,209) of the bore (5,205), such that, in use, any fuel entering the bore (5,205) through the control fuel line connection (8,208) acts upon a thrust surface (12,212) provided on the valve member (3,203) resulting in a force acting on the valve member (3,203) in a direction to open the fuel pressure regulator (1,201). There is provided an upper clearance (6,206) between the valve member (3,203) and the second end (9,209) of the bore (5,205), and a fuel spill line connection (13,213) positioned in the bore (5,205) such that, in use, any fuel entering the bore (5,205) through the fuel spill line connection (13,213) enters a region between the first end (11,211) and the second end (9,209) of the bore (5,205). A lower clearance(30,230) is provided in the bore (5,205) between the first end (11,211) and the second end (9,209), and a leak passageway is connected from a point between the lower clearance(30,230) and the second end (9,209) of the bore (5,205), and a fuel return line connection (14,214), such that, in normal operating use, a fuel flow path from the fuel spill line connection (13,213) to the fuel return line connection (14,214) is kept open when the fuel pressure regulator (1,201) is in the non-regulating position.
Abstract:
The present application relates to a pump unit (1) for a fuel injection system. The pump unit (1) has a low pressure fuel supply line (11) and a high pressure fuel outlet (13). A pumping chamber (5) having a plunger (15) is operable to perform a pumping cycle comprising a pumping stroke and a filling stroke. The pump unit (1) also includes an inlet valve (7) having an inlet valve member (19) movable between an open position for permitting the supply of fuel to the pumping chamber (5) from the low pressure fuel supply line (11) and a closed position for inhibiting the supply of fuel from the pumping chamber (5) to the low pressure supply line (11). An outlet valve (9) is provided in the high pressure fuel outlet (13). The pump unit (1) also includes a means (39) for latching the inlet valve member (19) in its open position. The present application also relates to a method of operating a pump unit (1).
Abstract:
The present application relates to a pump unit (101; 201; 201') for a fuel injection system. The pump unit (101; 201; 201') has an inlet valve (107; 207), an outlet valve (109; 209), a supply line (111; 211) for supplying fuel, a pumping chamber (105; 205; 205'), and a plunger (119; 217; 217') for pressurising fuel in the pumping chamber (105; 205; 205'). The inlet valve (107; 207) comprising an inlet valve member (113; 221; 221') movable between a first position and a second position. The inlet valve member (113; 221; 221') has an aperture (117; 229) formed therein. The aperture (117; 229) provides a first fluid pathway between the pumping chamber (105; 205; 205') and the supply line (111; 211) when the inlet valve member (113; 221; 221') is in its first position, and the aperture (117; 229) provides a second fluid pathway between the pumping chamber (105; 205; 205') and the outlet valve when the inlet valve member is in its second position.
Abstract:
A fuel pipe assembly for supplying fuel to a fuel injector (9) located within a bore (7) of an engine cylinder head (3) comprises a tube nut (115; 150) for connecting the fuel pipe (5) to the fuel injector (9) and a securing arrangement comprising a locking nut (70) and a deformable clamp means (80) for securing the fuel pipe (5) within the tube nut (115; 150). The tube nut (115; 150) comprises a tubular member (115a; 150a) defining an axial bore (17) to receive the fuel pipe (5), a distal end (115b; 150b) shaped for cooperation with the head (5a) of the fuel pipe (5), and a proximal end (115c; 150c) having attachment means for engaging compatible attachment means of the locking nut (70). The locking nut (70) has an axial bore (71) to receive the fuel pipe (5), and attachment means for engaging compatible attachment means of the tube nut (115; 150). The clamp means (80) defines a bore (83) to receive the fuel pipe (5) and is deformable under compression. In a first state of engagement, the locking nut (70) and tube nut (115; 150) define a volume therebetween that accommodates the clamp means (80) in an unstrained configuration and the fuel pipe (5) is able to move laterally. In a second state of engagement, the clamp means (80) is compressed between the locking nut (70) and tube nut (115; 150) into a strained configuration such that lateral movement of the fuel pipe (5) is constrained.
Abstract:
The present application relates to a pump unit (101; 201; 201') for a fuel injection system. The pump unit (101; 201; 201') has an inlet valve (107; 207), an outlet valve (109; 209), a supply line (111; 211) for supplying fuel, a pumping chamber (105; 205; 205'), and a plunger (119; 217; 217') for pressurising fuel in the pumping chamber (105; 205; 205'). The inlet valve (107; 207) comprising an inlet valve member (113; 221; 221') movable between a first position and a second position. The inlet valve member (113; 221; 221') has an aperture (117; 229) formed therein. The aperture (117; 229) provides a first fluid pathway between the pumping chamber (105; 205; 205') and the supply line (111; 211) when the inlet valve member (113; 221; 221') is in its first position, and the aperture (117; 229) provides a second fluid pathway between the pumping chamber (105; 205; 205') and the outlet valve when the inlet valve member is in its second position.
Abstract:
The present application relates to a pump unit (301) for a fuel injection system. The pump unit (301) comprises an inlet sealing ring (311), a pumping chamber (305) and a plunger (321) for pressurising fuel in the pumping chamber (305). The inlet sealing ring (311) is movably mounted on the plunger (321). The sealing ring (311) is movable between a first position in which a fluid pathway between the pumping chamber (305) and a supply line (317) for supplying fuel is open, and a second position in which the fluid pathway between the pumping chamber (305) and the supply line is closed (317).
Abstract:
The present application relates to a pump unit (101; 201; 201') for a fuel injection system. The pump unit (101; 201; 201') has an inlet valve (107; 207), an outlet valve (109; 209), a supply line (111; 211) for supplying fuel, a pumping chamber (105; 205; 205'), and a plunger (119; 217; 217') for pressurising fuel in the pumping chamber (105; 205; 205'). The inlet valve (107; 207) comprising an inlet valve member (113; 221; 221') movable between a first position and a second position. The inlet valve member (113; 221; 221') has an aperture (117; 229) formed therein. The aperture (117; 229) provides a first fluid pathway between the pumping chamber (105; 205; 205') and the supply line (111; 211) when the inlet valve member (113; 221; 221') is in its first position, and the aperture (117; 229) provides a second fluid pathway between the pumping chamber (105; 205; 205') and the outlet valve when the inlet valve member is in its second position.
Abstract:
A control method for a high-pressure fuel pump comprising a plurality of pump elements (17), each of which comprises a plunger (10) having a pumping stroke during which fuel within a pump chamber (6) is pressurised and a filling stroke during which fuel is supplied to the pump chamber (6) for pressurisation, and a valve (18) for controlling fuel flow into and/or out of the pump chamber (6). The high-pressure fuel pump has a maximum pump capacity corresponding to all of the pump elements pumping at maximum capacity. The method comprises reducing the pump capacity of the high-pressure fuel pump by reducing the pump duty of at least one of the pump elements to less than its maximum capacity.