Method for the production of an electronically controlled butterfly valve with an inductive sensor of “contact-free” type for an internal combustion engine

A method for the production of a butterfly valve having a valve body housing a valve seat engaged by a butterfly disc keyed on a shaft in order to rotate under the action of an electric motor, the shaft being coupled to a contact-free inductive position sensor provided with a rotor which is rigid with the shaft and is housed in a chamber of the valve body, and a stator which is borne by a detachable cover adapted to close the chamber and is disposed, in operation, facing the rotor, the method comprising the steps of:

• coupling the rotor to the shaft;
• mounting the stator on the cover, said stator being provided with at least one reading device adapted to supply a reading signal depending on the position of the rotor, and a filter device adapted to linearise the reading signal supplied by the reading device;
• completing any remaining machining operations on the butterfly valve;
• coupling the cover to the valve body in order to close the chamber in a substantially permanent manner;
• and
• carrying out a calibration of the position sensor by setting the filter device and disposing the shaft in a sequence of predetermined positions.

A method for the production of a butterfly valve having a valve body housing a valve seat engaged by a butterfly disc keyed on a shaft in order to rotate under the action of an electric motor, the shaft being coupled to a contact-free inductive position sensor provided with a rotor which is rigid with the shaft and is housed in a chamber of the valve body, and a stator which is borne by a detachable cover adapted to close the chamber and is disposed, in operation, facing the rotor, the method comprising the steps of:

• coupling the rotor to the shaft, the electric motor being coupled to the shaft by a gear transmission which is housed within the chamber and ends in a final gear keyed on the shaft and bearing the rotor of the position sensor, said rotor including a plane metal winding which is closed in short-circuit, has a series of lobes and is at least partly embedded in the final gear, the metal winding having a surface facing the stator of the position sensor which is substantially coplanar with an outer surface of the final gear;
• mounting the stator on the cover;
• completing any remaining machining operations on the butterfly valve;
• coupling the cover to the valve body in order to close the chamber in a substantially permanent manner;
• and
• carrying out a calibration of the position sensor by disposing the shaft in a sequence of predetermined positions.