Abstract: A dodge plunger, a nozzle spring, and a needle valve are received in a main body of a fuel injection nozzle in this order forwardly. The first fuel passage and the second fuel passage are formed in the main body. A distal end of the first fuel passage faces the needle valve, and a basal end thereof is open to a basal end face of the main body. A distal end of the second fuel passage faces the dodge plunger, and a basal end thereof is open to the basal end face of the main body. The basal ends of the first and second fuel passages are away from and independent of each other on the basal end face of the main body. A plug is attached to the basal end of the main body. A third fuel passage is formed in this plug. A distal end of the third fuel passage is in communication with the basal ends of the first and second fuel passages. The basal ends of the first and second fuel passages are in communication with each other only through the distal end of the third fuel passage.

Abstract: A stem of a poppet valve of a fuel injection nozzle has a plurality of first injection ports and a plurality of second injection ports formed in an area in the vicinity of a valve portion of the poppet valve. One open end of the first injection ports are spacedly circumferentially aligned. One open end of the second injection ports are likewise spacedly circumferentially aligned. The one open end of the first injection ports are located downwardly of the one end of the second injection ports. The one open end of the first and second injection ports are axially aligned. When an engine is revolving at a low speed, fuel is injected from only the first injection ports, and when the engine is revolving at a high speed, fuel is injected from the first and second injection ports.

Abstract: A dodge plunger, a nozzle spring and a needle valve are received in a main body in this order toward a distal end of the body. The dodge plunger is of a hollow construction and has a pressure intake chamber and a guide hole arranged in this order toward the needle valve. A central plunger is slidably received in the guide hole of the dodge plunger. One end of the central plunger is faced with the pressure intake chamber. The central plunger projects from the dodge plunger toward the needle valve and is received in the nozzle spring. After the pilot injection is started as a result of lifting of the needle valve, the dodge plunger is lifted. As a consequence, a fuel pressure is introduced into the pressure intake chamber via a secondary valve seat. The central plunger is biased by the received fuel pressure and urges the needle valve toward the main valve seat.

Abstract: In a fuel injector, a plurality of pairs of first and second injection ports are formed in a distal end portion of a nozzle body, and are spaced from one another peripherally of the nozzle body. The angles of the first and second injection ports relative to an axis of the nozzle body is different from each other. The inner ends of the first injection ports are disposed at a valve seat, and the inner ends of the second injection ports are spaced from the inner ends of the first injection ports toward the distal end of the nozzle body in the axial direction of the nozzle body. Each pair of first and second injection ports have a substantially common outer end. At an initial stage of the lift of the needle valve, the injection of fuel from the first injection ports is effected preferentially due to a throttle effect between the abutment portion and the valve seat.

Abstract: There is disclosed a fuel injection nozzle which can change a fuel injection direction in accordance with a fuel injection amount. A plurality of pairs of first and second injection ports are formed in a distal end portion of a nozzle body, and are spaced from one another in the direction of the periphery of the nozzle body. The angle of the first injection port relative to the axis of the nozzle body is acute, and is smaller than the angle between the second injection port and the axis of the nozzle body. Inner ends of the first injection ports are disposed at a valve seat, and inner ends of the second injection ports are spaced from the inner ends of the first injection ports toward the distal end of the nozzle body. Each pair of first and second injection ports have a substantially common outer end. When a tapered conical abutment portion of a needle valve is seated on the valve seat, the inner ends of the first injection ports face the out peripheral surface of the abutment portion.

Abstract: There is disclosed an improved cam for a fuel injection pump. The cam has a mountain-like cam projection at its surface disposed in contact with a roller. The cam projection has a lift region extending from a leading end thereof to a peak thereof. At the lift region, the cam is lifted in response to the rotation of the cam, so that a plunger is moved to pressurize fuel in a pump chamber. The lift region has first, second and third angle portions arranged in this order from the leading end of the cam projection toward the peak of the cam projection. The first angle portion serves to increase a lift speed of the cam, and terminates in a position where the lift speed becomes the maximum. The second angle portion serves to lower the lift speed. The deceleration is greater at an initial section of the second angle portion than at a final portion of the second angle portion.

Abstract: An injection timing control device for a distributor-type fuel injection pump, has a timer piston slidable within a cylinder in response to a difference between pump chamber pressure and the force of a timer spring to thereby rotate a roller holder for varying the fuel injection timing. A movable seat member is urged by a second spring toward the timer piston, and has one end thereof disposed for urging contact with one end face of the timer piston, which has a total effective pressure receiving area at which the pump chamber pressure acts on upon the timer piston. The total effective pressure receiving area is decreased while the seat member abuts against the one end face of the timer piston.

Abstract: In a method for detecting the fuel injection performance of a fuel injection valve in which a nozzle needle biased by a spring member for establishing valve opening pressure is lifted off from the valve seat when pressurized fuel is supplied thereto, electric data corresponding to the wave form of the shock wave produced in the spring member when fuel is injected is detected at one end of the spring member, and time-course change in the pressure of injected fuel acting on the nozzle needle during the fuel injection operation is determined on the basis of the time-course change in magnitude of the shock wave returning from the nozzle needle side end in the spring member by reflection, whereby various fuel injection factors can be calculated from the determined pressure of injected fuel acting on the nozzle needle during the fuel injection operation.

Abstract: A fuel injector includes a pressure chamber and/or a damper chamber to damp the movement of a plunger and a piston after fuel injection has ended. A fuel bypass communicates with the pressure chamber or damper chamber to prevent fuel pressure within the chamber from rising as a consequence of the damping action. The bypass prevents the pressure in the chamber from increasing to the point where the movement of the plunger would be reversed and pressurized fuel would once again be supplied to the nozzle causing secondary injection. The damper chamber and bypass thus serve to prevent bumping between the plunger and the surrounding cylinder and also to prevent secondary injection.