Abstract: To provide a variable valve driving device which can accurately control the lift amount of valves and can be manufactured at a low cost. The device has: valves (10) serving as intake valves or exhaust valves of an engine; springs (11) for biasing the valves (10) in the valve closing direction; a cam (12) for pressing the valves (10) in the valve opening direction against a biasing force of the springs; a piston (19) joined to the valves (10); a control chamber (21) configured by a piston insertion hole (20) into which the piston (19) is inserted; and a control mechanism (24) for changing the valve closing timing of the valves (10) by controlling the introduction and discharge of a working fluid into and from the control chamber (21).

Abstract: To provide a variable valve driving device which can accurately control the lift amount of valves and can be manufactured at a low cost. The device has: valves (10) serving as intake valves or exhaust valves of an engine; springs (11) for biasing the valves (10) in the valve closing direction; a cam (12) for pressing the valves (10) in the valve opening direction against a biasing force of the springs; a piston (19) joined to the valves (10); a control chamber (21) configured by a piston insertion hole (20) into which the piston (19) is inserted; and a control mechanism (24) for changing the valve closing timing of the valves (10) by controlling the introduction and discharge of a working fluid into and from the control chamber (21).

Abstract: A diesel engine comprising a fuel injection device (9), an EGR device (19), and a control device (26) for controlling the fuel injection device (9) and EGR device (19) so as to realize a premixed combustion in which a mixture is ignited after the end of fuel injection, the diesel engine further comprising detection unit (31) for detecting the ignition timing of the mixture, wherein when the actual ignition timing detected by the detection unit (31) shifts from the preset optimum ignition timing, the control device (26) corrects the timing of fuel injection conducted by the fuel injection device (9) and matches the actual ignition timing with the optimum ignition timing.

Abstract: A diesel engine includes a fuel injection device (9), an external EGR device (19), an internal EGR device (29), and a control device (26) for controlling the fuel injection device (9), external EGR device (19), and internal EGR device (29), wherein the control device (26) implements in a prescribed operation region a premixed combustion in which the fuel is injected before the vicinity of the top dead center and the EGR of a comparatively large quantity is implemented, and implements outside the prescribed operation region a normal combustion in which the fuel is injected in the vicinity of the top dead center and the EGR of a small quantity is implemented. The control device (26) controls the EGR ratio by using both the external EGR device (19) and the internal EGR device (29) when the premixed combustion is implemented and controls the EGR ratio by using only the external EGR device (19) when the normal combustion is implemented.

Abstract: A diesel engine includes a fuel injection device (9), an external EGR device (19), an internal EGR device (29), and a control device (26) for controlling the fuel injection device (9), external EGR device (19), and internal EGR device (29), wherein the control device (26) implements in a prescribed operation region a premixed combustion in which the fuel is injected before the vicinity of the top dead center and the EGR of a comparatively large quantity is implemented, and implements outside the prescribed operation region a normal combustion in which the fuel is injected in the vicinity of the top dead center and the EGR of a small quantity is implemented. The control device (26) controls the EGR ratio by using both the external EGR device (19) and the internal EGR device (29) when the premixed combustion is implemented and controls the EGR ratio by using only the external EGR device (19) when the normal combustion is implemented.

Abstract: A diesel engine comprising a fuel injection device (9), an EGR device (19), and a control device (26) for controlling the fuel injection device (9) and EGR device (19) so as to realize a premixed combustion in which a mixture is ignited after the end of fuel injection, the diesel engine further comprising detection unit (31) for detecting the ignition timing of the mixture, wherein when the actual ignition timing detected by the detection unit (31) shifts from the preset optimum ignition timing, the control device (26) corrects the timing of fuel injection conducted by the fuel injection device (9) and matches the actual ignition timing with the optimum ignition timing.

Abstract: An object of the present invention is to obtain a consistently stable needle lift damping effect in an injector 8b for fuel injection. In an injector 8b that relieves fuel pressure inside a pressure control chamber 37 and lifts a needle valve 36, there are provided a damper member 62 that is slidably mounted to the needle valve 36, a damping chamber 63 formed between the damper member 62 and the needle valve 36, a leak passage 64 for extracting and leaking out the fuel in the damping chamber 63, and a stopper member 41 to restrict the lift position of the damper member 62. Damping of the lift of the needle valve 36 is carried out by extracting and leaking out the fuel in the damping chamber 63 through the leak passage 64. The needle valve 36 functions as a guide for the damper member 62, and prevents vibration of the damper member 62, allowing a consistently stable damping effect to be obtained.

Abstract: A variable-delivery high-pressure fuel pump having a pump chamber varying in volume as a plunger moves in and out, an inlet port valve forming a part of chamber walls of the pump chamber, the inlet port valve being opened when a low-pressure fuel is admitted into the pump chamber, while being closed when the admitted fuel is delivered out of the pump chamber, a control chamber on an opposing end of the inlet port valve to receive the low-pressure fuel from the fuel inlet passage, and a control valve for intermittently opening and blocking a fluid communication between the control chamber and the fuel inlet passage. The inlet port valve is a poppet valve made with a valve head having a valve face moving off and reseating against a valve seat in the pump chamber, and a valve stem integral with the valve head and extending out of the pump chamber into the control chamber.

Abstract: Disclosed is a common-rail fuel injection system which regulates an amount of fuel delivered at every plunger in a high-pressure fuel-supply pump, thereby enabling to control an actual common-rail pressure restored at every fuel delivery forced by the plunger so as to come in matching a desired common-rail pressure. A fundamental desired amount of fuel delivered is found dependent on the desired common-rail pressure derived from the engine operating conditions. A correction amount of fuel delivered is calculated at every plunger on the basis of a deviation in the common-rail pressure, which is derived from the actual common-rail pressure restored with the fuel delivery and sensed at every fuel delivery. Each plunger delivers under pressure an ultimate amount of fuel that is compensated with the correction amount of fuel delivered, thereby making the common-rail pressure coincide with the desired common-rail pressure.

Abstract: In the fuel injection method and device for engines, information obtained from the differential value of the common rail pressure is used to correct the parameters of the command pulses to the flow control valve and the solenoid valve of each injector and thereby limit deviations of the fuel injection characteristic of the injector from the target injection characteristic. From the curves of the differential values R of the common rail pressure Pc, the actual fuel injection parameters for the injectors-injection start timing Tis, gross injection amount Qt, initial injection amount Qe and maximum injection rate Rmax-are obtained.

Abstract: A fuel injector (1) including a nozzle body (3) and a needle valve (4) liftably received in a nozzle body hole (21, 34) such that fuel flows to injection openings (16) of the nozzle body through a clearance between the nozzle body hole and needle valve. The clearance includes a larger clearance portion (37) and a smaller clearance portion (38) in series in a fuel flowing direction. The needle valve (4) has a collar (20) to almost plug the larger clearance portion (37) and a throttled fuel passage (22) is formed in the collar (20). Since the collar transversely extends in the larger clearance segment, it has a relatively large area subjected to the fuel pressure. Fuel pressure acts on this large area so that a large pressure difference is obtained across the collar during needle valve opening. Thus, it is possible to close the needle valve at a high speed.

Abstract: This fuel injection device changes stepwise the effective opening area of the exhaust opening that releases the fuel pressure in the balance chamber, in order to control the lift velocity of the needle valve to give flexibility to the pattern of the initial fuel injection rate. The fuel injection device of this invention switches the current value applied to the solenoid between the large and the small value to change the distance traveled by the solenoid valve and thereby change the opening degree of the exhaust port that releases the fuel pressure in the balance chamber. Because the return spring mechanism having plural springs, the magnitudes of current necessary to be applied to the solenoid to move the solenoid valve are clearly differentiated. This reduces variations in the process of releasing the fuel pressure in the balance chamber, assuring a stable fuel injection rate control.

Abstract: A fuel injection system includes a fuel injector having a body, a needle valve movably provided in the body and a fuel accumulator having two chambers for storing a fuel at high and low pressures. An injection chamber is formed in the injector lower body and a control chamber is formed in the injector upper body. An injection passage connects the high pressure chamber with the injection chamber and a control passage connects the low pressure chamber with the control chamber. The needle valve is lifted upon leaking of the fuel to the accumulator from the control chamber and the fuel is injected from the injection chamber upon lifting of the needle valve. The fuel is recycled to the fuel tank from the control chamber.