Denso Corporation

Hiroto Fujii

Katsumi Mori

Nobuhiro Akashi

A spool valve is movably provided in a valve sliding space of a valve casing. The spool valve has a through-hole formed in the inside thereof, and a communication port formed in the spool valve is operatively communicated with a fluid port for controlling an opening area of the fluid port by moving within the valve sliding space. Multiple circular oil grooves are formed at an outer peripheral surface of the spool valve, into which high pressure fluid is supplied so that the spool valve can be smoothly moved in the valve sliding space.

Flow control valve

A fuel injection system for an internal combustion engine is provided which includes a fuel injector equipped with an actuator and a nozzle needle. The actuator works to lift the nozzle needle to inject fuel into an internal combustion engine. A controller controls an operation of the actuator to change an amount of lift of the nozzle needle a given number of times for a target injection duration, thereby ensuring the uniformity of size of atomized particles of the fuel sprayed from the fuel injector.

Fuel injection system designed to enhance uniformity of size of atomized particles of fuel

A common rail injection system for internal combustion diesel engines is provided which is designed to correct a limit of width of an ineffective injection command pulse signal which is to be applied to each fuel injector, but causes the injector to produce no spray of fuel in order to minimize a variation in quantity of fuel injected to the engine between the injectors arising from the individual variability or aging of the injectors. The system works to changes the width of a pilot injection command pulse signal to search a value thereof when an engine operation variation such as a change in speed of the engine exceeds or decreases below a threshold at which the injector may be viewed as having sprayed the fuel actually or stopped spraying the fuel actually and determines the limit of width of the ineffective injection command pulse signal using the searched value.

Accumulator fuel injection apparatus compensating for injector individual variability

An apparatus aims at learning a deviation from a reference injection characteristic of a fuel injector provided for a cylinder of an engine having an output shaft. In the apparatus, a detecting unit is configured to detect a minimum interval between temporally adjacent fuel injection periods in the plurality of fuel injection periods based on a behavior of the output shaft during execution of the plurality of fuel injections. The minimum interval maintains the temporally adjacent fuel injection periods to be non-overlapped with each other. A learning unit is configured to learn the deviation from the reference injection characteristic of the fuel injector based on the detected minimum interval.

Fuel injection control system

A method is provided to manufacture a fuel injection control system controlling fuel injection in an internal combustion engine with a fuel injection valve. A fuel injection valve is trial-manufactured. Using this valve, correcting amounts for an injection period are calculated at plural adjustment points defined by fuel pressures and injection periods. The adjustment points are divided into actual-measuring points and predicting points, and the correcting amounts at the actual-measuring points are used to calculate predicting expressions to predict correcting amounts at the predicting points and relational expressions to define a relationship among the correcting amounts at the actual-measuring points. When the valve is mass-manufactured, for each mass-manufactured valve, the correcting amounts at the actual-measuring points and the predicting expressions are used to predict correcting amounts at the predicting points, providing the correcting amounts at the actual-measuring and correcting points. Appropriateness of the predicting expressions is also estimated.

Apparatus and method for manufacturing fuel injection control systems

A common rail fuel injection apparatus for an engine is provided which is equipped with a rail pressure sensor working to measure the pressure of fuel in a common rail, fuel injectors, and a controller. When the operation state of the rail pressure sensor monitored to be unusual, the controller changes the value of electricity supplied to an actuator of one of the fuel injectors to induce a change in a preselected operation characteristic of the engine. Upon appearance of such a change, the controller estimates the value of the rail pressure using the changed value of the electricity and a physical property of balance among forces acting on a valve of one of the fuel injectors which has induced the change in operation characteristic of the engine. The estimated value of the rail pressure is used for subsequent injections of the fuel into the engine.

Fuel injection system ensuring operation in event of unusual condition

An injector has a housing, a command piston, a control chamber, a needle, a nozzle chamber, a fuel inflow passage, a fuel discharge passage and an electric valve. The housing slidably supports the command piston and the needle. The housing and one end face of the command piston enclose the control chamber. The needle is disposed at the other end face side of the command piston. The housing and a leading end portion of the needle enclose the nozzle chamber to accumulate the high-pressure fuel therein. The housing is provided with an injection hole, which is opened and blocked by the needle. The fuel discharge passage opens at a fuel discharge port to the control chamber to discharge the high-pressure fuel out of the control chamber. The fuel discharge port is close to an uppermost position of the command piston.

Growing community of inventors

Kariya, Japan

Hiroto Fujii