摘要:
The device comprises a pressure pump for pumping fuel from a reservoir to aressure duct connected to an accumulator. This supplies a series of injectors for an internal combustion engine. The device further includes a pair of solenoid valves disposed between the pump and the accumulator, which are controlled by an electronic unit as a function of data on the pressure in the accumulator detected by a sensor. The solenoid valve is normally closed to discharge fuel received from the pump into the reservoir and is opened to deliver this fuel to the accumulator. On the other hand the solenoid valve is normally open to deliver fuel received to the accumulator and is closed to discharge the fuel from the accumulator into the reservoir. Between the two solenoid valves and is disposed a non-return valve.
摘要:
A perfected fuel injector comprising a plunger for controlling fuel passage between an injection chamber and at least an injection orifice formed in an injection nozzel; and an electromagnetic fuel metering valve for controlling fuel passage through a drain orifice between a control chamber, supplied with fuel under pressure, and a low-pressure chamber, so as to reduce to a given value the pressure of the fuel inside the control chamber and so displace the plunger. Pressurized fuel is supplied to the injection chamber and control chamber by means of a single fitting connected to a supply pipe and coming out inside a supply orifice formed in the injector body and communicating with the control chamber and with a duct supplying fuel to the injection chamber and comprising an annular chamber and a radial hole formed in a sleeve housed in a hole on the body.
摘要:
The fuel injection system comprises a fuel injector controlled by commands of a control unit. The fuel injector comprises a metering servo valve having a control chamber provided with an outlet passage that is opened/closed by an open/close element that is axially movable. The open/close element is carried by an axial guide element that is separate from an armature of an electromagnet. The open/close element is held in the closing position by a spring acting through an intermediate body. In some instances, the strokes of the open/close element and of the armature are chosen so as to eliminate, upon closing of the servo valve, the rebounds of the open/close element subsequent to the first rebound. The control unit controls a fuel injection comprising a pilot fuel injection and a main fuel injection, via two distinct electrical commands, which are spaced apart by a dwell time such as to occur in an area of reduced variation of the amount of injected fuel. Therefore, the stability of operation of the fuel injection system increases as the dwell time varies.
摘要:
A fuel injector has an injector body and a control rod, which is movable in the injector body along an axis to control the opening/closing of a nozzle that injects fuel into a cylinder of the engine; the injector body houses a metering servovalve having a control chamber, which is axially delimited by the control rod and communicates with an inlet and with a discharge channel; the metering servovalve is provided with a shutter, which slides axially on an axial guide, from which the discharge channel exits, to open and close the discharge channel and, in consequence, vary the pressure in the control chamber; the discharge channel has at least two restrictions having calibrated passage sections and arranged in series with each other to divide the pressure drop along the discharge channel.
摘要:
The injector comprises a balanced metering servovalve to control a rod for the opening/closing of a nozzle. La servovalve has a valve body with a control chamber radially delimited by a tubular portion and fitted with an outlet passage that is opened/closed by an axially movable shutter. The servovalve is also integral with an axial stem, provided with a lateral surface, through which the outlet channel exits. The shutter is coupled to the stem in an axially sliding manner and, when it closes the outlet passage, it is subjected to substantially null axial fuel pressure. The outlet passage has a calibrated segment distanced from the shutter and close to a bottom wall of the control chamber. The calibrated segment is carried by an element fixed to the valve body in correspondence to an axial segment of the outlet passage.
摘要:
On-off valve intended to be arranged at the outlet of the gas accumulation reservoir in an electronic gas injection system for an internal combustion engine, presenting a valve member made of metallic material, co-operating with a valve seat made in a body, which is also made of metallic material, to ensure the good quality of tightness in all operative temperature and pressure conditions, with prolonged reliability in time.
摘要:
A fuel adjustment and filtering device for a high-pressure pump of a fuel injection system, the device comprising at least one filter, comprising a removable filter cartridge, comprising a filtering body, housed within a filter casing; a shut-off solenoid valve for metering fuel; and, a pressure control valve for the fuel. The solenoid valve and pressure control valve are housed in a block separate from the pump. In one embodiment, in which the pressure control valve is optional, the solenoid valve may be mounted on the filter casing.
摘要:
An injection system includes a high-pressure pump with at least one pumping element operated in a reciprocating manner by corresponding intake and discharge strokes. Each pumping element is equipped with a corresponding intake valve in communication with an intake line, fed by a low-pressure pump. An on-off solenoid valve is positioned on the intake line of the pump and is controlled by a control unit with a frequency equal to a whole multiple or submultiple of that of the pumping action, multiplied by a factor different from 1 and/or between 0.90 and 1.10, inclusive.
摘要:
A fuel injector and servovalve for an internal combustion engine. In one embodiment, the fuel injector comprises a casing; a balanced metering servovalve in the casing that controls movement of an injection control rod along an axial cavity; said servovalve having; a valve body comprising a control chamber; an axial stem comprising a discharge channel having at least one radial segment that runs to a lateral surface of said axial stem; a calibrated inlet passage in communication with said control chamber; and an outlet passage in communication with said control chamber and the discharge channel; a sleeve having a shutter, said axial stem extending into said sleeve in a fluid tight manner and so that said sleeve that can axially slide along said axial stem between a closed position and an open position of said at least one radial segment, thereby controlling said movement of said injection control rod along said axial cavity; an electro-actuator having an armature that controls said axial sliding of said sleeve along said axial stem; an elastic member that exerts a force upon said armature that maintains said sleeve in said closed position, said electro-actuator being able to control said armature to overcome said force of said elastic member; and said armature being separate from said sleeve.
摘要:
A fuel adjustment and filtering device for a high-pressure pump of a fuel injection system, the device comprising at least one filter, comprising a removable filter cartridge, comprising a filtering body, housed within a filter casing; a shut-off solenoid valve for metering fuel; and, a pressure control valve for the fuel. The solenoid valve and pressure control valve are housed in a block separate from the pump. In one embodiment, in which the pressure control valve is optional, the solenoid valve may be mounted on the filter casing.