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: The present invention provides a method for controlling a closing operation of an exhaust valve (11) in an internal combustion engine. A current position X0 of the exhaust valve (11) and a rotation speed Ne of the internal combustion engine are determined, and on the basis of the current position X0 and rotation speed Ne, a time T0 at which a piston arrives at the current position X0 of the exhaust valve (11) is calculated. The closing operation of the exhaust valve (11) is then started before this arrival time T0. Next, a time T1 at which the gap between the exhaust valve (11) and piston reaches a first predetermined value hc1 is calculated, and when this time T1 arrives, the closing operation of the exhaust valve (11) is stopped temporarily. A time T2 at which the piston arrives at the stopping position X1 of the exhaust valve (11) is then calculated, and the closing operation of the exhaust valve (11) is resumed before this arrival time T2.

Abstract: The object of the present invention is to provide a camless valve driving device, without having a cam mechanism, which can reduce the valve driving energy and enhances fuel efficiency. According to the one preferred aspect of the present invention, the valve driving device of an internal combustion engine includes a pressure chamber, to which actuating fluid, to drive opening and closing of a main valve serving as an intake valve or as an exhaust valve of the internal combustion engine, is supplied; a first actuating valve for supplying high-pressure (Pc) actuating fluid to the pressure chamber during a prescribed period (tCP1) of the initial valve opening period of the main valve; a second actuating valve for introducing low-pressure (Pf) actuating fluid to the pressure chamber after the prescribed period (tCP1) has elapsed; a third actuating valve for discharging actuating fluid from the pressure chamber when the main valve is closed.

Abstract: The present invention provides a method for controlling a closing operation of an exhaust valve (11) in an internal combustion engine. A current position X0 of the exhaust valve (11) and a rotation speed Ne of the internal combustion engine are determined, and on the basis of the current position X0 and rotation speed Ne, a time T0 at which a piston arrives at the current position X0 of the exhaust valve (11) is calculated. The closing operation of the exhaust valve (11) is then started before this arrival time T0. Next, a time T1 at which the gap between the exhaust valve (11) and piston reaches a first predetermined value hc1 is calculated, and when this time T1 arrives, the closing operation of the exhaust valve (11) is stopped temporarily. A time T2 at which the piston arrives at the stopping position X1 of the exhaust valve (11) is then calculated, and the closing operation of the exhaust valve (11) is resumed before this arrival time T2.

Abstract: In an internal combustion engine of a premixed charge compression self-ignition type in which fuel and intake gas are premixed with each other, and the mixture is compressed and self-ignites, target ignition timing determination means (42) to determine a target ignition timing ? based on at least an engine operation state, target compression ratio determination means (41) to determine a target compression ratio (?t) required for the mixture to ignite, and control means (26) to control opening and closing of an intake valve (7) so that an effective compression ratio at the target ignition timing (?) becomes equal to the target compression ratio (?t) are provided. According to this, the ignition timing of the fuel can be appropriately controlled.

Abstract: In an internal combustion engine of a premixed charge compression self-ignition type in which fuel and intake gas are premixed with each other, and the mixture is compressed and self-ignites, target ignition timing determination means (42) to determine a target ignition timing ? based on at least an engine operation state, target compression ratio determination means (41) to determine a target compression ratio (?t) required for the mixture to ignite, and control means (26) to control opening and closing of an intake valve (7) so that an effective compression ratio at the target ignition timing (?) becomes equal to the target compression ratio (?t) are provided. According to this, the ignition timing of the fuel can be appropriately controlled.

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: The object of the present invention is to provide a camless valve driving device, without having a cam mechanism, which can reduce the valve driving energy and enhances fuel efficiency. According to the one preferred aspect of the present invention, the valve driving device of an internal combustion engine includes a pressure chamber (18), to which actuating fluid, to drive opening and closing of a main valve (11) serving as an intake valve or as an exhaust valve of the internal combustion engine, is supplied; a first actuating valve (20) for supplying high-pressure (Pc) actuating fluid to the pressure chamber (18) during a prescribed period (tCP1) of the initial valve opening period of the main valve; a second actuating valve (34) for introducing low-pressure (Pf) actuating fluid to the pressure chamber (18) after the prescribed period (tCP1) has elapsed; a third actuating valve (30) for discharging actuating fluid from the pressure chamber (18) when the main valve (11) is closed.

Abstract: A valve driving device reduces the volume of the pressure chamber and decreases the energy supplied during driving to open the main valve. As a result of this initial energy, the main valve is lifted by inertial motion. When the main valve is opened (lifted), a first actuating valve is opened, and high-pressure actuating fluid is supplied to the pressure chamber. When in this process the pressure in the pressure chamber falls below the pressure of a low-pressure chamber, a second actuating valve opens independently, and low-pressure actuating fluid is introduced into the pressure chamber. By this means negative pressure in the pressure chamber can be prevented, and the main valve can be held in a lift position equivalent to the initial energy. When the main valve is to be closed, an actuator forcibly opens the second actuating valve.

Abstract: A valve driving device reduces the volume of the pressure chamber and decreases the energy supplied during driving to open the main valve. As a result of this initial energy, the main valve is lifted by inertial motion. When the main valve is opened (lifted), a first actuating valve is opened, and high-pressure actuating fluid is supplied to the pressure chamber. When in this process the pressure in the pressure chamber falls below the pressure of a low-pressure chamber, a second actuating valve opens independently, and low-pressure actuating fluid is introduced into the pressure chamber. By this means negative pressure in the pressure chamber can be prevented, and the main valve can be held in a lift position equivalent to the initial energy. When the main valve is to be closed, an actuator forcibly opens the second actuating valve.

Abstract: A common-rail fuel-injection system is disclosed for finding controlled variables such as an initial quantity of fuel injected in accordance with a start-delay time and adjusting the controlled variables to their desired value to thereby help ensure the reliable control and also the compensation in scattering of the initial fuel-injection characteristics. When selecting an initial quantity of fuel injected as the controlled variable of the initial injection, a desired, initial quantity Qi0 of fuel injected is found on a lookup map C in accordance with the engine operating conditions, and a pull-in voltage Vp or current Ip is found on a lookup map D in compliance with the desired, initial quantity Qi0 of fuel injected. An initial quantity Qi of fuel injected is found on a data, having been obtained previously, in compliance with a start-delay time T spanning from a timing the injector is applied with an instruction to initiate the fuel injection till a timing of the start of an actual fuel injection.

Abstract: In a boiling water nuclear reactor, a reactor primary cooling water line is filled with water at the start-up time, and the inside of a pressure vessel is pressurized by a pressurized tank and at the same time control rods are withdrawn to thereby heat cooling water in a state of single-phase flow to high temperature. Succeedingly, the pressurization is released and the pressure of the pressure vessel is gradually approximated to the saturation pressure corresponding to the cooling water temperature to thereby make the cooling water transit into a state of two-phase flow, and thereafter the cooling water is heated by nuclear reaction in the state of two-phase flow to thereby obtain predetermined reactor running temperature and pressure.