Abstract: The invention relates to a pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine, comprising at least one cylinder (14), a piston (15) which is displaceably arranged in the cylinder (14), and a pressure valve (30) for selectively controlling the supply of fuel to the internal combustion engine, wherein the pressure valve (30) has a closure part (38, 46, 51) provided with a cavity (44, 49, 53) that opens to the outside on an end surface (43, 48, 52) facing the piston (15) of the closure part (38, 46, 51).

Abstract: A pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine, the pump unit comprising: a head (2) inside which a cylinder (3) is formed along an axis (A) for housing a sliding pumping piston (4); an intake valve (8) positioned inside an intake hole (7) between an intake chamber (9) and a compression chamber (10) upstream and downstream of the intake hole, respectively; a plug (11) sealingly connected to the head (2) so as to close the intake chamber; wherein the sealed connection is formed by means of forced surface-to-surface engagement between a portion of an inner surface of an annular wall of the head and a portion of an outer surface of an annular wall of the plug.

Abstract: The invention relates to a pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine, comprising at least one cylinder (14), a piston (15) which is displaceably arranged in the cylinder (14), and a pressure valve (30) for selectively controlling the supply of fuel to the internal combustion engine, wherein the pressure valve (30) has a closure part (38, 46, 51) provided with a cavity (44, 49, 53) that opens to the outside on an end surface (43, 48, 52) facing the piston (15) of the closure part (38, 46, 51).