Abstract: A diesel engine has a fuel injection nozzle to which pressurized fuel is supplied from a pump. The nozzle has a pressure sensor detecting the fuel pressure and a lift sensor sensing a lift magnitude of a needle valve. An electronic control unit (ECU) computes a variation ratio of the fuel pressure value which is measured by the pressure sensor. The ECU computes a non-increasing point in an increasing part of variation ratio and judges the point to be a timing for starting the fuel injection of the nozzle. The EPU also computes the actual fuel injection amount in accordance with the fuel injection timing as well as the fuel pressure and the lift amount of the needle valve both at the various points. The EPU controls the actual injection amount to be identical to a target fuel injection amount.

Abstract: A diesel engine has a fuel injection nozzle to which pressurized fuel is supplied from a pump. The nozzle has a pressure sensor detecting the fuel pressure and a lift sensor sensing a lift magnitude of a needle valve. An electronic control unit (ECU) computes a variation ratio of the fuel pressure value which is measured by the pressure sensor. The ECU computes a non-increasing point in an increasing part of variation ratio and judges the point to be a timing for starting the fuel injection of the nozzle. The ECU also computes the actual fuel injection amount in accordance with the fuel injection timing as well as the fuel pressure and the lift amount of the needle valve both at the various points. The ECU controls the actual injection amount to be identical to a target fuel injection amount.

Abstract: A fuel injection system with a fuel injection pump. The system comprises first correction means for correcting a first basic volume of fuel fed by the fuel injection pump using a correction value calculated so as to realize a predetermined constant engine speed during at least one predetermined engine operating condition, calculation mean for calculating the variation of the correction value corresponding to the fuel temperature at predetermined engine load in the predetermined engine operating condition, and determining means for determining at least one property of current fuel on the basis of the variation. Accordingly, the system can automatically detect the properties of a fuel while driving.

Abstract: A diesel engine has a fuel injection nozzle to which pressurized fuel is supplied from a pump. The nozzle has a pressure sensor detecting the fuel pressure and a lift sensor sensing a lift magnitude of a needle valve. An electronic control unit (ECU) computes a variation ratio of the fuel pressure value which is measured by the pressure sensor. The ECU computes a non-increasing point in an increasing part of variation ratio and judge the point to be a timing for starting the fuel injection of the nozzle. The EPU also computes the actual fuel injection amount in accordance with the fuel injection timing as well as the fuel pressure and the lift amount of the needle valve both at the various points. The EPU control the actual injection amount to be identical to a target fuel injection amount.

Abstract: An exhaust gas purification system for an internal combustion engine includes an engine capable of fuel combustion at lean air-fuel ratios, a catalyst constructed of zeolite carrying at least one kind of metal selected from transition metals and noble metals to reduce NOx under oxidizing conditions and in the presence of HC, engine operating condition detecting means for detecting the current engine operating condition, engine operating range determining means for determining whether or not the current engine operating condition is within an insufficient HC amount range, and an HC amount control means for controlling the amount of HC included in the exhaust gas when the engine operating range determining means determines that the engine operating condition is within the insufficient HC amount range.

Abstract: A two-stroke engine having an intake valve and an exhaust valve arranged on an inner wall of the cylinder head, an intake passage connected to the cylinder via the intake valve, a fuel injection device arranged in the cylinder, for injecting fuel into the cylinder, a pressure regulator for regulating a fuel pressure supplied to the fuel injection device on the basis of a scavenging pressure in the intake passage, to thereby increase the fuel pressure in accordance with an increase of the scavenging pressure, and a control device for controlling the injection of fuel by the fuel injection device for a time ranging from a time at which the intake valve is opened to a time at which the scavenging pressure becomes equal to a pressure in the cylinder after the intake valve is closed.

Abstract: A two stroke engine equipped with a mechanically driven supercharger in the intake passage downstream of throttle valve. A bypass air passage bypassing the supercharger is provided, and a bypass air control valve is arranged in the bypass air passage. When the engine is idling, the bypass air control valve is controlled so that the level of vacuum in the intake passage between the throttle valve and the supercharger is maintained at a constant value.

Abstract: In a two stroke fuel injection type internal combustion engine provided with intake and exhaust valves, a basic amount of fuel to be injected is calculated in accordance with an engine load and engine speed. Values of a factor corresponding to a ratio of air captured by an engine cylinder for combustion to the total amount of air introduced into the engine are stored in a memory in accordance with combinations of an engine load and engine speed. A value of a captured air factor corresponding to a detected combination of an engine load and speed is calculated by a map interpolation. The basic amount is corrected by the captured air factor so that a desired air-fuel ratio is obtained. The captured air factor may be further corrected in accordance with a secondary engine condition, other than an engine load and speed, such as a cooling water temperature, intake air temperature, atmospheric air temperature, atmospheric air pressure, exhaust gas temperature, or intake pressure.

Abstract: A two-stroke internal combustion engine comprising a cylinder head 14 having combustion chambers 18 with two intake valves 24 and two exhaust valves 26 arranged therein. Two intake manifolds 30 and 32, respectively, have branch pipes connected to each respective intake port 24. An intake control valve 48 l is arranged in one of the manifold 32, which closes at idling and under a low load of the engine. Further, a swirl S is generated about an axis of the combustion chamber 18 by a portion of exhaust gas caused to flow back from the exhaust ports 22 into the combustion chamber 18 after being once exhausted through the exhaust ports when the exhaust valves are opened, resulting in a two layered stratification in the combustion chamber between fresh air and remaining exhaust gas. A supply of fuel causees a further three layered stratification among a fuel mixture, fresh air, and burned gas, by supplying fuel at alternating cycles of the engine when the engine is under a low load.

Abstract: A two-cycle internal combustion engine having three, or a multiple of three, cylinders comprises a cylinder head having an intake port and exhaust port opened to a combustion chamber, to which fresh air compressed by a supercharger is introduced via an intake valve. The intake and exhaust valves are operated in response to a crank angle. A one-way valve is provided in the intake port so as to prevent air or gas from flowing back toward the supercharger. The exhaust valve is opened earlier than the intake valve when the speed of the downward movement of the piston is relatively high, so that a part of exhaust gas in the exhaust port flows back to the combustion chamber in the condition. In a heavy load condtion, cross scavenging and air charging effects due to exhaust pulsation can be achieved.

Abstract: A two-cycle internal combustion engine comprises a cylinder head having two intake ports and an exhaust port opened to a combustion chamber, to which compresses fresh air is introduced via two intake valves. The intake and exhaust valves are operated in response to a crank angle. During an idling or light load running condition, an air control valve closes the second intake port. The exhaust valve is opened earlier than the second intake valve, and the first intake valve is opened later than the second intake valve, while the speed of the downward movement of the piston is relatively high. An exhaust gas swirl rotating around a cylinder axis is formed when the exhaust gas flows back into the condition chamber and the fresh air is slowly introduced via the first intake valve onto the exhaust gas swirl in the idling or light load condition. A large amount of fuel is rapidly introduced into the combustion chamber via the second intake valve in a heavy load condition.

Abstract: A two-cycle internal combustion engine comprises a cylinder head having an intake port and two exhaust ports opened to a combustion chamber, to which compressed fresh air is introduced via an intake valve. The intake valve and two exhaust valves are operated in response to a crank angle. One of the exhaust valves is opened earlier than the other exhaust valve and the intake valve when the speed of the downward movement of the piston is relatively high, such that a part of exhaust gas in the one exhaust port flows back to the combustion chamber in that condition. An exhaust gas swirl rotating around a cylinder axis is formed when the exhaust gas flows back and the fresh air is slowly introduced onto the exhaust gas swirl in that condition.

Abstract: A two-cycle internal combustion engine comprises a cylinder head having an intake port and exhaust port opened to a combustion chamber, to which compressed fresh air is introduced via an intake valve. An inclined concavity is formed on a top face of a piston. An exhaust valve is opened earlier than the intake valve when the speed of the downward movement of the piston is relatively high, so that a part of exhaust gas in the exhaust port flows back to the combustion chamber in that condition. An exhaust gas swirl rotating around a cylinder axis is formed when the exhaust gas flows back and the fresh air is slowly introduced onto the exhaust gas swirl in that condition. The inclined concavity serves to smoothly guide the exhaust swirl.

Abstract: A two-cycle internal combustion engine comprises a cylinder head having an intake port and exhaust port opened to a combustion chamber, to which compressed fresh air is introduced via an intake valve. The intake and exhaust valves are operated in response to a crank angle. A pulsation pressure of exhaust gas in the exhaust port is substantially restrained during an idling or light load running condition. The exhaust valve is opened earlier than the intake valve when the speed of the downward movement of the piston is relatively high, such that a part of exhaust gas in the exhaust port flows back to the combustion chamber in that condition. An exhaust gas swirl rotating around a cylinder axis is formed when the exhaust gas flows back and the fresh air is slowly introduced onto the exhaust gas swirl in that condition.