A high-pressure injection device for an internal combustion engine to which engine segment times are assigned, having a high-pressure pump, a rail connected to the high-pressure pump via a high-pressure fuel line, at least one injector, a digital pressure reduction valve connected to the rail, a fuel return line connected to the pressure reduction valve, and a control unit. The control unit is configured to switch the pressure reduction valve into the transmissive state only in predetermined engine segment times, and to maintain said transmissive state of the pressure reduction valve for a time period which is greater than the duration of one engine segment time.

The present invention relates to a method for operating an internal combustion engine provided as a medium-speed gas engine or dual fuel engine in a gas fuel mode. The method comprises the step of directly injecting a gas fuel into a combustion chamber of the engine at a maximum injection pressure that is lower than a compression-end pressure of the engine.

A method to estimate the temperature of an electromagnetic actuator, which entails a preliminary step in which to define a first threshold value for the current or for the voltage; and define a characteristic curve of the actuator family in the plane temperature/time needed to reach the threshold value; a step in which to carry out a reference measurement, in which, using the characteristic curve, a reference time needed by the electromagnetic actuator to reach the first threshold value is associated with a known reference temperature; and a step in which to carry out a series of measurements in which to determine the time needed by the electromagnetic actuator to reach the first threshold value, calculate the deviation between the time needed by the electromagnetic actuator to reach the first threshold value and the reference time; and determine the temperature of the electromagnetic actuator, using the characteristic curve, by associating the temperature of the electromagnetic actuator with the sum of the deviation and of the reference time.

Disclosed is a method for optimizing the time gradient of the pressure increase in a fuel injection system of a hybrid motor vehicle. The method determines and uses the engine torque generated by the electric machine of the vehicle to reduce the engine torque generated by the internal combustion engine of the vehicle and allow the high-pressure pump of the internal combustion engine to generate, if applicable, a higher value of the time gradient of the pressure increase in the common supply chamber of its injection system.

An internal combustion engine with at least one combustion chamber, at least one fuel delivery line for the delivery of fuel to at least one combustion chamber, and at least one differential pressure control valve for controlling the pressure in the at least one fuel delivery line. The at least one differential pressure control valve is configured to perform a valve opening or valve closing movement based on a pressure difference between the at least one fuel delivery line and a reference volume having a reference pressure. The internal combustion engine further includes at least one pressure relief valve, separate from the at least one differential pressure control valve, and configured to open to cause a pressure relief in the reference volume and a decrease in the reference pressure if a drop occurs in the power to be performed by the internal combustion engine.

A method to estimate the temperature of an electromagnetic actuator, which entails a preliminary step in which to define a first threshold value for the current or for the voltage; and define a characteristic curve of the actuator family in the plane temperature/time needed to reach the threshold value; a step in which to carry out a reference measurement, in which, using the characteristic curve, a reference time needed by the electromagnetic actuator to reach the first threshold value is associated with a known reference temperature; and a step in which to carry out a series of measurements in which to determine the time needed by the electromagnetic actuator to reach the first threshold value, calculate the deviation between the time needed by the electromagnetic actuator to reach the first threshold value and the reference time; and determine the temperature of the electromagnetic actuator, using the characteristic curve, by associating the temperature of the electromagnetic actuator with the sum of the deviation and of the reference time.

In a control method of an internal combustion engine including a fuel injection valve having a plurality of injection holes and adapted to directly inject a fuel into a cylinder and an ignition plug adapted to generate a plug discharging channel, after fuel injection is performed, spark ignition is performed while turbulence in an air flow is generated by the fuel injection by an ignition plug disposed so that a discharging region is sandwiched by fuel sprays injected from the two adjacent injection holes and located within a range where the turbulence in the air flow is generated.

A vehicle includes a residual pressure holding valve provided downstream a feed pump of a fuel to hold a pressure in a fuel pipe leading to the port injection valve. Residual pressure holding valve is opened to return the fuel in the fuel pipe to the fuel tank when the pressure in the fuel pipe exceeds a valve opening pressure, and closed when the pressure in the fuel pipe is lower than the valve opening pressure. At the time of a request to reduce a target pressure of the fuel to be supplied to the electric feed pump, a control device refrains from causing the target pressure to decrease when a load of the engine is smaller than a prescribed value, and causes the target pressure to decrease when the load of the engine is greater than the prescribed value.

A fuel-supply system has a fuel pump, a pressure controller, a signal output device and a power switch. The pressure controller adjusts the observed fuel pressure of the fuel and may electronically communicate with a motor driving the fuel pump to regulate the supply of fuel from a fuel tank of the fuel-supply system to an engine. In detail, the pressure controller performs feedback control of a voltage applied to the motor such that the pressure of a fuel pumped from the fuel pump approaches to have a first target and/or ideal fuel pressure value. Further, the signal output device outputs the first target fuel pressure value to the pressure controller. Activation of the power switch supplies power, from a power source, to the pressure controller, the motor and the signal output device. Further, the pressure controller may perform feedback control based on a second target fuel pressure value.

An internal combustion engine system includes an internal combustion engine including an in-cylinder injection valve and a fuel pressure adjustment mechanism, and a control device that executes fuel injection control at a time of automatic restart of the internal combustion engine that is automatically stopped, by controlling the in-cylinder injection valve and the fuel pressure adjustment mechanism, in which the control device includes a first controller that executes the compression stroke injection a first number of times after an automatic restart request is made and control the pressure of the fuel to a predetermined value, and a second controller that executes the intake stroke injection a second number of times after the compression stroke injection is executed the first number of times and make the pressure of the fuel lower than the predetermined value.