Ultrasonic welding device

1. Ultrasonic welding device; comprised of a sonotrode ( 1 ) attached by the back side to a booster ( 12 ) and in turn to a converter ( 13 ) suitable for connection to an actuator, handler or robotic arm responsible for its movement, and to which the head ( 2 ) is attached; is characterized by being comprised of: an outer sleeve ( 3 ) arranged around the sonotrode ( 1 ) and which delimits, along with that sonotrode ( 1 ) an annular chamber ( 4 ) for the circulation of pressurized air connected through the chamber ( 23 ) to a pressurized air inlet port ( 21 ) and which has a crenellated back end ( 31 ), for the outlet of pressurized air and the peripheral refrigeration of the sonotrode ( 1 ); the aforementioned outer sleeve ( 3 ) has a rear portion ( 32 ) assembled in the head ( 2 ) with the possibility of axial displacement, between: —a forward position in which the front end ( 31 ) of the outer sleeve ( 3 ) stands out frontally with regard to the tip ( 11 ) of the sonotrode ( 1 ); forming a pusher that exerts, through the action of some compressible means ( 51 ), a configurable pressure against the parts (P 1 , P 2 ) to be welded, in a peripheral zone close to the weld, while approaching the sonotrode ( 1 ) to the parts to be welded and before the tip ( 11 ) of the sonotrode ( 1 ) makes contact with the aforementioned parts to be welded, and —a backward position, determined by the advance of the sonotrode ( 1 ) during welding while the front end ( 31 ) of the outer sleeve ( 3 ) keeps the parts (P 1 , P 2 ) to be welded pressed together, and in which backward position the front end ( 31 ) of the outer sleeve ( 3 ) is arranged in a coplanar manner, or in a very close plane, to the tip ( 11 ) of the sonotrode ( 1 ).

2. The device, according to claim 1 , is characterized by the rear portion ( 32 ) of the outer sleeve ( 3 ) which is housed in a chamber ( 23 ) of the head ( 2 ) which is conveyed through a perforated cylindrical bushing ( 6 ) with the lateral pressurized air inlet ( 21 ) defined in the aforementioned head ( 2 ); this rear portion ( 32 ) of the outer sleeve ( 3 ) is comprised of a crenellated back ( 33 ) and some radial bores ( 34 ) for the passage of pressurized air from the chamber ( 23 ) of the head ( 2 ) toward the annular chamber ( 4 ) defined between the external sleeve ( 3 ) and the sonotrode ( 1 ).

3. The device, according to claim 2 , is characterized by the cylindrical perforated bushing ( 6 ) which is housed in a peripheral seat ( 24 ) defined in the chamber ( 23 ) of the head ( 2 ) and which is attached to this seat by means of a retainer ( 7 ).

4. The device, according to claim 3 , is characterized by the retainer ( 7 ) that contains a sealing gasket ( 71 ) which acts against the sliding support ( 5 ), preventing outside leaks of pressurized air through the space between the support ( 5 ) and the head ( 2 ).

5. The device, according to claim 1 , is characterized by being comprised of: a support ( 5 ) attached externally to an intermediate zone of the outer sleeve ( 3 ) and which moves along with the aforementioned outer sleeve ( 3 ), between the forward and backward positions; some compressible means ( 51 ) that act on the head ( 2 ) and tend to hold it in the forward position, and a mechanical stop ( 22 ) that delimits the advance of the support ( 5 ) in the forward position.