WIRE FEEDER.

摘要

This invention provides a wire feeder for a wire-cut electric discharge machine, capable of retreating when an electric discharge machining is carried out a wire transfer belt from a position in which wires are automatically connected, whereby the wear of the belt and the fluctuation of the wire feed speed can be prevented. In order to carry out an automatic wire connecting operation, an air cylinder (27) for a wire feed mechanism (16) is driven, so that a second transfer belt (15 min ) is moved from a position of retreat to a position of automatic connection via a parallel link mechanism (23, 25, 25 min , 25 sec ), in which position the second transfer belt (15 min ) is pressed against a first transfer belt (15). When a motor (M2) is actuated to cause these two belts to be turned, a wire electrode (5) held between the same belts is moved from the upstream side of a wire transfer path to the downstream side thereof to complete the automatic connection. When the air cylinder is thereafter deenergized, the second transfer belt is returned to the position of retreat by the resilient force of a spring (26), thus being separated from the first transfer belt. Consequently, the wire electrode and the two belts are put in a non-contacting state, whereby the wear of the wire and the fluctuation of the wire feed speed are prevented. There is provided a wire feed apparatus of a wire cut electric discharge machining apparatus, capable of shunting a wire conveyor belt from an automatic wire extension position at the time of electric discharge machining, thereby preventing wear of the belt and variation in wire feed speed. At the time of automatic wire extension, an air cylinder (27) of a wire feed mechanism (16) is driven to move a second conveyor belt (15 min ) from a shunt position to the automatic wire extension position through the medium of a parallel link mechanism (23, 25, 25 min , 25 sec ), and the second conveyor belt (15 min ) is pressed against a first conveyor belt (15) at the automatic wire extension position. When both these belts rotate as a motor (M2) is driven, a wire electrode (5) held between the belts is transported from the upper-course side of a wire transfer path to the lower-course side thereof, whereupon the automatic wire extension is finished. When the air cylinder is de-energized, thereafter, the second conveyor belt is restored to the shunt position to be separated from the first conveyor belt, by means of the urging force of a spring (26), so that the wire electrode and the two belts are out of contact with one another, thus preventing wear of the wire and variation in wire feed speed.