Abstract: A pressure boosting unit (110) is provided in each fuel injection valve of an engine (1). A pressure of fuel to be supplied to the fuel injection valve from a common rail (3) is boosted as required. An ECU (20) causes low pressure injection to be performed with the pressure boosting unit 110 being in a non-operated state, and high pressure injection to be performed with the pressure boosting unit (110) being in an operated state, and the pressure of the fuel being maintained at a boosted pressure. Based on the result, the ECU (20) corrects a fuel injection period of the fuel injection valve. Also, after the correction of the fuel injection period is completed, fuel injection is performed before the pressure of the fuel reaches the boosted pressure after the pressure boosting unit starts to be operated. Based on the result, operation starting timing of the pressure boosting unit is adjusted.

Abstract: A gas-mixture-ignition-time estimation apparatus for an internal combustion engine estimates the temperature of a premixed gas mixture for PCCI combustion (i.e., cylinder interior temperature Tg), while relating it to the angle CA, on the basis of a state quantity of the cylinder interior gas at the time of start of compression (CAin) (heat energy of the cylinder interior gas at the time of start of compression), the amount of a change in the state quantity of the cylinder interior gas attributable to compression in a compression stroke (minute piston work), and the heat generation quantity of a cool flame generated in PCCI combustion prior to autoignition (hot flame) (cool flame heat generation quantity Aqlto). A time when the cylinder interior temperature Tg reaches a predetermined autoignition start temperature Tig is estimated as an autoignition start time (Caig) of the premixed gas mixture related to PCCI combustion.

Abstract: A needle is forced to open an injection hole by reducing a pressure of fuel in an injection control chamber to thereby inject fuel stored in a fuel storage, while the needle is forced to close the injection hole by increasing the pressure of fuel in the injection control chamber to thereby terminate injection of fuel from the injection hole. In a valve-closing stroke of the needle to close the injection hole, fuel pressure is supplied from a common accumulator to the fuel storage and the injection control chamber in such a manner that the pressure to supply fuel to the fuel storage is lower than that to supply fuel to the injection control chamber. In this way, a force acting on the needle toward the injection hole side can be increased in the valve-closing stroke, to thereby accelerate a valve-closing speed of the needle.

Abstract: A gas-mixture-ignition-time estimation apparatus for an internal combustion engine estimates the temperature of a premixed gas mixture for PCCI combustion (i.e., cylinder interior temperature Tg), while relating it to the angle CA, on the basis of a state quantity of the cylinder interior gas at the time of start of compression (CAin) (heat energy of the cylinder interior gas at the time of start of compression), the amount of a change in the state quantity of the cylinder interior gas attributable to compression in a compression stroke (minute piston work), and the heat generation quantity of a cool flame generated in PCCI combustion prior to autoignition (hot flame) (cool flame heat generation quantity Aqlto). A time when the cylinder interior temperature Tg reaches a predetermined autoignition start temperature Tig is estimated as an autoignition start time (Caig) of the premixed gas mixture related to PCCI combustion.

Abstract: A pressure boosting unit (110) is provided in each fuel injection valve of an engine (1). A pressure of fuel to be supplied to the fuel injection valve from a common rail (3) is boosted as required. An ECU (20) causes low pressure injection to be performed with the pressure boosting unit 110 being in a non-operated state, and high pressure injection to be performed with the pressure boosting unit (110) being in an operated state, and the pressure of the fuel being maintained at a boosted pressure. Based on the result, the ECU (20) corrects a fuel injection period of the fuel injection valve. Also, after the correction of the fuel injection period is completed, fuel injection is performed before the pressure of the fuel reaches the boosted pressure after the pressure boosting unit starts to be operated. Based on the result, operation starting timing of the pressure boosting unit is adjusted.

Abstract: In a direction control valve, a bottom face of an insertion hole of a first movable member is at a predetermined distance from a second movable member with respect to a first axial direction when communication between a first communication switching port and a communication object port is made and communication between a second communication switching port and the communication object port is broken. The bottom face contacts and pushes the second movable member in a second axial direction opposite to the first axial direction after the first movable member moves in the second axial direction by the predetermined distance while the first and second movable members move in the second axial direction to switch a port communicating with the communication object port from the first communication switching port to the second communication switching port.

Abstract: In fuel injector including an accumulator and an intensifier, fuel is injected such that an injection control valve and a piston control valve are individually controlled, an operational phase difference therebetween is regulated, and at least one of a maximum injection pressure, a rate of increase of an injection pressure at the start of an increase of pressure, a rate of decrease of the injection pressure at the completion of injection, a pilot injection pressure, and an after injection pressure of fuel injected from a fuel injection nozzle is arbitrarily changed. Namely, a pressure during a movement from a base common rail pressure of the accumulator to a static maximum pressure statically determined by an operation of the intensifier is positively used as a control factor of injection, whereby a fuel injection pattern can be implemented with an extremely high degree of freedom.

Abstract: A fuel injection device is provided which can inject fuel by very high injection pressure and can realize favorable combustion and exhaust characteristics, and moreover, enables performance of fuel injection with arbitrary fuel injection patterns. In the fuel injection device 30, the protrusion 61 is provided at a distal end portion of the piston control valve 60 which is provided at the pressure intensifier 54, can change a practical opening area of the fuel flow path 57 to the cylinder 56 in accordance with movement of the piston control valve 60, and can control inflow amounts of liquid fuel that is flowed into the cylinder 56 by the piston control valve 60 (does orifice control). Thus, control of injection rates and injection pressures of fuel that is injected from the fuel injection nozzle 34 is enabled, and fuel injection patterns can be realized with an extremely high degree of freedom.

Abstract: A fuel injection device is provided which can inject fuel by very high injection pressure and can realize favorable combustion and exhaust characteristics, and moreover, enables performance of fuel injection with arbitrary fuel injection patterns. In the fuel injection device 30, the protrusion 61 is provided at a distal end portion of the piston control valve 60 which is provided at the pressure intensifier 54, can change a practical opening area of the fuel flow path 57 to the cylinder 56 in accordance with movement of the piston control valve 60, and can control inflow amounts of liquid fuel that is flowed into the cylinder 56 by the piston control valve 60 (does orifice control). Thus, control of injection rates and injection pressures of fuel that is injected from the fuel injection nozzle 34 is enabled, and fuel injection patterns can be realized with an extremely high degree of freedom.

Abstract: To obtain a fuel injection method in a fuel injector capable of realizing excellent combustible and exhaustive characteristics, and carrying out fuel injection with an arbitrary fuel injection pattern thus allowing a degree of freedom of a fuel injection pattern to further expand. In an fuel injector comprising an accumulator and an intensifier, fuel is injected such that an injection control valve and a piston control valve are individually controlled, an operational phase difference therebetween is regulated, and at least one of a maximum injection pressure, a rate of increase of an injection pressure at the start of an increase of pressure, a rate of decrease of the injection pressure at the completion of injection, a pilot injection pressure, and an after injection pressure of fuel injected from a fuel injection nozzle is arbitrarily changed.