High-pressure fuel pump with variable delivery quantity
AssigneeRobert Bosch GmbH
InventorsHelmut Rembold, Bruno Schmidt, Dietmar Krieg, Mathias Schumacher, Uwe Mueller
Life of this patent
Estimating the term…
Abstract
A high-pressure fuel pump which is suitable above all for use in internal combustion engines with direct gasoline injection, in which the pressure surge upon opening of a check valve between the high-pressure line and the pumping chamber of the fuel feed pump is limited by structural provisions.
Claims14
A high-pressure fuel pump with a variable delivery quantity for an internal combustion engine, comprising a piston (10) actuated by a camshaft (12) wherein the piston (10) aspirates fuel from a low-pressure line (15) into a pumping chamber (14) and then pumps it into a high-pressure line (16), and a quantity control valve (19) connecting the pumping chamber (14) and the low-pressure line (15), and a separate suction valve (18) disposed between the low-pressure line (15) and the pumping chamber (14), the regulation of the delivery quantity being effected by opening the quantity control valve (19) during the pumping stroke of the piston, wherein said quantity control valve (19) is a magnet valve that is open when without current.
A high-pressure fuel pump with a variable delivery quantity for an internal combustion engine, comprising a piston (10) actuated by a camshaft (12) wherein the piston (10) aspirates fuel from a low-pressure line (15) into a pumping chamber (14) and then pumps it into a high-pressure line (16), and a quantity control valve (19) connecting the pumping chamber (14) and the low-pressure line (15), and a separate suction valve (18) disposed between the low-pressure line (15) and the pumping chamber (14), the regulation of the delivery quantity being effected by opening the quantity control valve (19) during the pumping stroke of the piston, wherein the quantity control valve (19) is regulated by a control unit as a function of the rpm, load, and temperature of the internal combustion engine, the voltage of the on-board electrical system, and the temperature of the aspirated air and the pressure in the common rail.
A high-pressure fuel pump with a variable delivery quantity for an internal combustion engine, comprising a piston (10) actuated by a camshaft (12) wherein the piston (10) aspirates fuel from a low-pressure line (15) into a pumping chamber (14) and then pumps it into a high-pressure line (16), and a quantity control valve (19) connecting the pumping chamber (14) and the low-pressure line (15), and a separate suction valve (18) disposed between the low-pressure line (15) and the pumping chamber (14), the regulation of the delivery quantity being effected by opening the quantity control valve (19) during the pumping stroke of the piston, the camshaft having at least one cam (13), wherein each cam (13) of the camshaft (12) has at least a first rotational angle range (1), a second rotational angle range (2) and a third rotational angle range (3), the bottom dead center (BDC) of the piston (23) being located within the first rotational angle range (1);
- that after reaching BDC, in the first rotational angle range (1), the piston (10) is imparted a positive acceleration by the cam (13);
- that within the second rotational angle range (2) the stroke speed (Vr) of the piston (10) is approximately constant;
- that the quantity control valve (19) opens while the cam (13) is passing through the second rotational angle range;
- and that within the third rotational angle range (3), the stroke speed (Vr) of the piston (10) increases until a maximum value (Vmax) is reached.
Dependencies are inferred from the claim text.