Patent ID: 8291588

Claim:
A method of manufacturing and controlling a butterfly valve ( 1 ) for an internal combustion engine ( 1 ); the butterfly valve ( 1 ) comprises: a valve body ( 2 ); a tubular feeding pipe ( 4 ) defined in the valve body ( 2 ); a rotational shaft ( 6 ) which rotates about a rotation axis ( 7 ); a butterfly plate ( 5 ), which is arranged inside the feeding pipe ( 4 ) and is keyed onto the rotational shaft ( 6 ) to rotate between an opening position and a closing position of the feeding pipe ( 4 ); a catch element ( 34 ), which limits the rotation of the rotational shaft ( 6 ), forming a mechanical end stroke which defines a maximum closing position physically reachable by the rotational shaft ( 6 ); a position sensor ( 25 ) for detecting the angular position of the rotational shaft ( 6 ); and an actuator device connected to the rotational shaft ( 6 ) to rotate the rotational shaft ( 6 ) itself; the manufacturing and control method comprises the steps of: establishing a maximum gaseous flow rate value (V max ) which may flow through the feeding pipe ( 4 ) when the butterfly plate ( 5 ) is in the closing position; determining a conventional closing position at which the gaseous flow rate which flows through the feeding pipe ( 4 ) is essentially equal to the maximum gaseous flow rate value (V max ); and driving the actuator device so as not to normally pass the conventional closing position; the manufacturing and control method is characterized in that it comprises the further steps of: dimensioning a position of the catch element ( 34 ), so that when the rotational shaft ( 6 ) abuts against the catch element ( 34 ) the gaseous flow rate which flows through the feeding pipe ( 4 ) is essentially lower than the maximum gaseous flow rate value (V max ); using the position of the rotational shaft ( 6 ) abutting against the catch element ( 34 ) as offset point for calibrating and programming the position sensor ( 25 ); and determining, during an initial step of calibrating, a reading supplied by the position sensor ( 25 ) when the rotational shaft ( 6 ) is brought to the conventional closing position at which the gaseous flow rate which flows through the feeding pipe ( 4 ) is equal to the maximum gaseous flow rate value (V max ).