Patent ID: 7685997

Claim:
A control method of a fuel feeding system ( 15 ) in a bi-fuel internal combustion engine ( 1 ); the feeding system ( 15 ) comprises: a least a first injector ( 12 a ) adapted to inject a first fuel type; a least a second injector ( 12 b ) adapted to inject a second fuel type; a common electronic control unit ( 13 ) adapted to drive both injectors ( 12 ); and a switching device ( 14 ), which is controlled by the common electronic control unit ( 13 ) and is adapted to electrically connect both injectors ( 12 ) to the common electronic control unit ( 13 ) by means of at least a first relay ( 16 a ) adapted to connect/disconnect the first injector ( 12 a ) to/from the common electronic control unit ( 13 ) and by means of at least a second relay ( 16 b ) adapted to connect/disconnect the second injector ( 12 b ) to/from the common electronic control unit ( 13 ); the control method comprises: closing the first relay ( 16 a ) and opening the second relay ( 16 b ) for driving the first injector ( 12 a ) and injecting the first fuel type; opening the first relay ( 16 a ) and closing the second relay ( 16 b ) for driving the second injector ( 12 b ) and injecting the second fuel type; determining the real opening time (t o ) and the real closing time (t c ) of both relays ( 16 ); determining a desired switching instant (t comm ); sending the closing command of a relay ( 16 ) in advance with respect to the desired switching instant (t comm ) according to the real closing time (t c ) of the relay itself ( 16 ); and sending the opening command of a relay ( 16 ) in advance with respect to the desired switching instant (t comm ) according to the real opening time (t c ) of the relay itself ( 16 ).