Abstract:
The object of the present invention is to provide a high-pressure fuel supply apparatus, in which the durability of the fuel sealing section is improved and additionally the evaluation time is reduced. The high-pressure fuel supply apparatus comprises a piston having a plunger supported slidably within a cylinder and a tappet, a casing for preventing the fuel leaking out of the space between the cylinder and the piston from leaking outside by surrounding substantially the cylinder and the piston, and a sealing means for sealing the space between the casing and the piston, wherein the sealing means is fastened to the casing and brought into a slidable contact with the tappet of the piston. The sealing means may either be brought into slidingly contact with the cylindrical surface of the tappet that is fitted in the plunger or be brought into contact with a columnar tappet that simply abuts against one end of the plunger and is supported by the casing in a way in which it can move axially but it does not move radially. The tappet may be made of ceramics.
Abstract:
A high pressure fuel supply apparatus is constituted by a plunger reciprocating in a sleeve of a high pressure fuel pump so as to form a fuel pressurizing chamber between the plunger and the sleeve, a suction valve provided in a fuel suction port for sucking fuel into the fuel pressurizing chamber, and a discharge valve provided in a fuel discharge port for discharging fuel from the fuel pressurizing chamber into a high pressure fuel discharge passageway communicating with an internal combustion engine, the discharge valve reciprocating axially so as to perform an open/close operation, wherein the high pressure fuel supply apparatus further comprises a holder for regulating an axial reciprocating movement of the discharge valve in the open/close operation within a predetermined range.
Abstract:
A variable delivery fuel supply device capable of improving linearity of discharge characteristics with respect to a rotational angle of a cam and reducing abrasion of the cam. The variable delivery fuel supply device comprises: fuel injection valves 1a to 1d respectively for injecting a fuel to cylinders of an internal combustion engine; a delivery pipe 2 for supplying a pressurized fuel to said fuel injection valves 1a to 1d; and a fuel pump 3 for taking a fuel from a fuel intake passage 24 through an intake valve 25 into a pressurization chamber 17 during an intake stroke, for pressurizing the fuel and for discharging the pressurized fuel through a discharge valve 26 to the delivery pipe 2 during a discharge stroke by reciprocating movement of a plunger 14 in each cylinder 13 from a bottom dead point to a top dead point; wherein the pressure in the pressurization chamber 17 is relieved at a position set to a predetermined value before reaching the top dead point in the course of the discharge stroke in which the plunger 14 of the fuel pump 3 moves from the bottom dead point to the top dead point.
Abstract:
A first fuel inlet, a second fuel inlet, a first fuel outlet, and a second fuel outlet of a valve assembly of a high-pressure fuel pump are formed radially outside an aperture portion of a fuel pressurization chamber.
Abstract:
When a fuel injection valve is mounted on an engine, a distance between a core and an armature during non-energization of a coil can be prevented from becoming narrow. The coil is arranged inside the core, and a body is fixedly secured at its one end to an end of the core. A housing is arranged outside the coil with its one end abutting a cylinder head. A cap is arranged at the other end of the housing, and abuts at its side opposite to the housing with a fastening unit. The armature is arranged for reciprocation inside the body, and is magnetically attracted to the magnetized core. A gap is formed between the housing and the body, with the cap and the core being fixed to each other, and upon mounting the valve on the engine, the housing and the fastening unit abut the cylinder head and the cap, respectively.
Abstract:
When a fuel injection valve is mounted on an engine, a distance between a core and an armature during non-energization of a coil can be prevented from becoming narrow. The coil is arranged inside the core, and a body is fixedly secured at its one end to an end of the core. A housing is arranged outside the coil with its one end abutting a cylinder head. A cap is arranged at the other end of the housing, and abuts at its side opposite to the housing with a fastening unit. The armature is arranged for reciprocation inside the body, and is magnetically attracted to the magnetized core. A gap is formed between the housing and the body, with the cap and the core being fixed to each other, and upon mounting the valve on the engine, the housing and the fastening unit abut the cylinder head and the cap, respectively.
Abstract:
The object of the present invention is to provide an electromagnetic valve for a variable discharge fuel supply apparatus with improved relief property and high-responsiveness, a small electromagnetic valve, reduced electric current consumption and increased responsiveness, wherein the valve seat has a valve seating surface present in a flat surface facing the direction of movement of the valve at substantially right angle, and the valve is provided with a flow path formed within the valve and a substantially ring-shaped flat landing surface that encircles the flow path within the valve and closes the flow path by coming into contact with the valve seating surface. The electromagnetic valve may be made to cause the outside of the valve to serve as a high pressure side and the flow path within the valve, as a low pressure side, and to cause both the landing surface of the valve and the valve seating surface of the valve seat to be in ring-shaped so that the valve and the valve seat come into contact only through the space between the outer boundary of the landing surface of the valve and the inner boundary of the valve seating surface of the valve seat. Further, the flow path may be formed in a place where it passes the vicinity of said electromagnetic solenoids at the downstream section of the valve. In addition, the flow path within the valve may extend piercing the valve to reach as far as the vicinity of the solenoid coils, and may be connected to the fuel flow path that is formed in the space between the valve outer boundary and the valve holder inner boundary and linked to the low pressure side, and the valve seat having the valve seating surface may be a part formed separately from the valve holder instead of the one united to the valve holder.