Abstract:
PROBLEM TO BE SOLVED: To solve a problem in a diesel engine conventionally forming a plurality of fuel sprays by directly injecting fuel from a fuel injection nozzle of a multiple nozzle hole structure into a combustion chamber in which a swirl flow of intake air is generated wherein NOx production can be reduced by timing retard, but incomplete combustion is significant, stable improvement of fuel economy and reduction of a black smoke generation amount are hard, and particularly, when the swirl flow is large, fuel sprays are overlapped, fuel concentration is locally raised, and incomplete combustion becomes more significant. SOLUTION: The diesel engine includes an overlapping avoiding configuration reducing overlapping of fuel sprays 45, 46 from adjoining nozzle holes 34a, 35a, and as the overlapping avoiding configuration, a valve timing mechanism 17 is provided, setting timings 29a, 50a, 51a being start points of valve closing action of intake valves 3c, 3c taking air into the combustion chamber 15 to before an intake bottom dead center B. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
A control system of an internal combustion engine changing an operating timing of a valve in an internal combustion engine where a valve drive cam (13) and a pump drive cam (150) are both provided on a valve camshaft (1) is provided. That control system has a device inhibiting the operating timing from being returned in a direction reverse to the direction of the target operating timing during change of the operating timing. Further, in the control system, the relative rotational phases of the valve drive cam and the pump drive cam are set considering utilization of the composite reaction torque of the valve operation drive reaction torque and the fuel pump drive reaction torque acting on the valve camshaft for changing the operating timing in the direction of the target operating timing.
Abstract:
PROBLEM TO BE SOLVED: To save energy by flexibly controlling the opening/closing timing of an exhaust valve. SOLUTION: The following cross-head large-sized two-cycle diesel engine is provided as an example. The engine comprises a plurality of cylinders each having at least one exhaust valve 11; at least one camshaft 28 having an exhaust cam 29 for operating the at least one exhaust valve for each cylinder; hydraulic actuators 34 installed in the exhaust valves, respectively, for moving the exhaust valves in the opening direction; hydraulic piston pumps 32 installed in the hydraulic actuators, respectively, and driven by corresponding cams on the camshaft; operating oil pipes 36 connected to the exhaust valves, respectively, for connecting the hydraulic piston pumps to the corresponding hydraulic actuators, respectively; additional gas exchange valves 46 installed in the cylinders, respectively; and an operation system for controlling the opening and closing of the additional gas exchange valves independently of the camshaft. COPYRIGHT: (C)2009,JPO&INPIT