Abstract: It is possible to perform a failure diagnosis of a pressure sensor with a simple structure without installing a dedicated circuit for the failure diagnosis. In a common rail type fuel injection control apparatus, a pressure control valve 12 is provided in a fuel return path from a common rail 1, and a rail pressure detected by a pressure sensor 11 can be controlled to match a target rail pressure through drive control of the pressure control valve 12 by an electronic control unit 4. The target rail pressure is calculated based on operational information of an engine 3. In the common rail type fuel injection control apparatus, learning processing is performed, in which a correction coefficient Cv is stored and updated as a learning value to correct energization characteristics of a median product of the pressure control valves 12 that are stored in the electronic control unit 4. At the same time, it is determined whether the learning value of the correction coefficient Cv is within a predetermined range.

Abstract: It is possible to perform a failure diagnosis of a pressure sensor with a simple structure without installing a dedicated circuit for the failure diagnosis. In a common rail type fuel injection control apparatus, a pressure control valve 12 is provided in a fuel return path from a common rail 1, and a rail pressure detected by a pressure sensor 11 can be controlled to match a target rail pressure through drive control of the pressure control valve 12 by an electronic control unit 4. The target rail pressure is calculated based on operational information of an engine 3. In the common rail type fuel injection control apparatus, learning processing is performed, in which a correction coefficient Cv is stored and updated as a learning value to correct energization characteristics of a median product of the pressure control valves 12 that are stored in the electronic control unit 4. At the same time, it is determined whether the learning value of the correction coefficient Cv is within a predetermined range.

Abstract: A guide hole extending axially, a valve seat and an injection port are coaxially formed on an elongated valve body in this order toward a distal end of the valve body. A pressurized fuel is introduced into a basal end of the guide hole. A valve element is slidably received in the guide hole of the valve body. Inclined passages are formed in one of the valve element and the valve body. When the valve element is lifted, the pressurized fuel flows, as a swirling current, between a valve portion and the valve seat, proceeds toward an exit of the injection port while swirling along an inner peripheral surface of the injection port, and is injected from the injection port. When the valve element is in the fully lifted position, an orifice for restricting an amount of fuel injected from the injection port per unit time is formed between the valve portion and the valve seat.

Abstract: A valve seat member is fixedly received in a lower end portion of an elongated body. The valve seat member has a valve seat and an injection port at its lower end portion. A valve element is axially movably received in the body. The valve element is fully lifted from a position where a valve portion formed on the lower end of the valve element sits on the valve seat to a position where an upper end portion of the valve element is brought into abutment with a stopper of the body. This fully lifted amount is determined by the thickness of a shim interposed between a first receiving surface of the body and a second receiving surface of the valve seat member. The lower end portion of the body and the valve seat member are welded over the entire periphery.

Abstract: A collision type of fuel injection nozzle that ensures full frontal collision between jets of fuel injected from the opposed second injection nozzle holes is provided, and a method of manufacturing the nozzle. The method includes forming fuel inlets that extend from the fuel passage and avoid the collision recess, simultaneously forming the at least one pair of injection nozzles holes in a straight line that intersects the fuel inlets and the collision recess and then fixing a cap over at least a peripheral portion of the injection holes. This manufacturing method permits the nozzle holes to be formed at the same time ensuring alignment of the outlets for collision and highly uniform atomization.