C.r.f. Societa Consortile Per Azioni

Alfonso Di Meo

Mario Ricco

Sisto Luigi De Matthaeis

Adriano Gorgoglione

Raffaele Ricco

Sergio Stucchi

Silvio Canale

A fuel injector for an internal-combustion engine houses, in a hollow injector body of its own, an injection-control valve, the valve body of which delimits, together with the injector body, an annular chamber designed to receive a fuel under pressure, and insulated in a fluid-tight way by a seal member carried by the valve body and made of plastic material.

Fuel injector for an internal-combustion engine

An internal combustion engine fuel injector () has a rod () movable along an axis () to open/close a nozzle, and a servovalve () having a control chamber () with a discharge passage () which is opened/closed by a shutter () movable axially under the control of an electro-actuator; the servovalve also has a fixed axial rod () having an outer lateral surface () through which the discharge passage () comes out; the shutter () is fitted to the axial rod () to slide axially in substantially fluidtight manner, and, when closing the discharge passage (), is subjected to substantially zero resultant axial pressure by the fuel; and a calibrated portion () of the discharge passage () is formed close to the outlet of the discharge passage to produce swirl and/or cavitation in the fuel outflow near to the closing area between the shutter () and the axial rod ().

Internal combustion engine fuel injector

A control servo valve is housed inside the casing of an internal combustion engine fuel injector, and has an actuator, a control chamber communicating with a fuel inlet and with a fuel outlet passage, and a shutter movable along an axis by the actuator between a closed position and an open position to close and open the outlet passage respectively; the servo valve also has a fixed axial rod interposed between the actuator and the control chamber; the outlet passage comes out through an outer lateral surface of the axial rod; and the shutter is defined by a sleeve which slides axially on the outer lateral surface, and, in the closed position, closes the outlet passage so as to be subjected to a zero axial resultant force by the pressure of the fuel.

Servo valve for controlling an internal combustion engine injection

The device includes a connection tube in communication with a hole of a rail for fuel under pressure, the tube being provided with an end swelling. The device has a first threaded element fixed to the rail in a position corresponding to the hole and a second threaded element designed to engage the first threaded element. Removably set between the hole and the swelling is a seal element designed to form a seal both with the hole and with the swelling. The seal element is a body of revolution equipped with a passage along a pre-set axis, and includes two end noses designed to be inserted in the swelling and in the hole, respectively, and two tapered seal stretches.

Device for connection between a rail for fuel under pressure and at least one injector, for an internal-combustion engine

In order to reduce the size of a tubular rail for a high-pressure fluid, the rail is obtained from a hollow body with an external diameter and an internal diameter, and has two terminal portions, each provided with an external milling to favour gripping thereof. The millings have an external diameter such as to ensure, together with a cylindrical portion of a coaxial element, a radial strength at least equal to that of the hollow body. Made between the hollow body and each cylindrical portion is a front connection. For this purpose, the cylindrical portion has a plane front surface, whilst each terminal portion has an internal milling with an internal diameter greater than the internal diameter of the hollow body so as to house the cylindrical portion and so as to form an annular shoulder. A washer of softer material is set between the annular shoulder and the front surface.

Connection system for a tubular rail for high-pressure fluid and a system for reducing the size of the rail

An internal combustion engine fuel injector () has a rod () movable along an axis () to open/close a nozzle, and a servovalve () having a control chamber () with a discharge passage () which is opened/closed by a shutter () movable axially under the control of an electro-actuator (); the servovalve () also has a fixed axial rod () having an outer lateral surface () through which the discharge passage () comes out; the shutter () is fitted to the axial rod () to slide axially in substantially fluidtight manner, and, when closing the discharge passage (), is subjected to substantially zero resultant axial pressure by the fuel; and the control chamber () is bounded radially by a tubular portion () formed in one piece with said axial rod ().

A control servo valve () is housed inside the casing of an internal combustion engine fuel injector (), and has an actuator (), a control chamber () communicating with a fuel inlet () and with a fuel outlet passage (), and a shutter () movable along an axis () by the actuator () between a closed position and an open position to close and open the outlet passage () respectively; the servo valve () also has a fixed axial rod () interposed between the actuator () and the control chamber (); the outlet passage () comes out through an outer lateral surface () of the axial rod (); and the shutter () is defined by a sleeve which slides axially on the outer lateral surface (), and, in the closed position, closes the outlet passage () so as to be subjected to a zero axial resultant force by the pressure of the fuel.

Servo valve for controlling an internal combustion engine fuel injector

The system has a high-pressure pump having a number of mechanical pumping elements for pumping high-pressure fuel to a common rail; and a number of injectors communicating with the rail and activated to inject a quantity of fuel sequentially into the corresponding cylinders of the engine. Each pumping element has a delivery at least equal to the maximum draw of each injector, and is activated in phase with at least one of the injectors to minimize the variations in fuel pressure in the rail. Each pumping element may be activated by a cam, which may even have a segmented profile to effect a portion of the travel of the respective pumping element in phase with a corresponding injector.

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Valenzano, Italy

Alfonso Di Meo