Patent ID: 8987638
Filing Date: 2015-03-24
Classification: B23K

Abstract:
1. An engine driven welding machine in which a welding generator is driven by an engine, and said engine performs an idle operation when a welding operation is stopped, comprising: an engine stop signal forming circuit which forms a stop signal for stopping an operation of said engine when time of said idle operation exceeds a predetermined time; a direct-current power supply independent and isolated from a battery or other power supplies, connected to an output terminal of said welding machine; voltage detecting means which detects a voltage change of said output terminal; a restart detecting circuit which forms a restart signal for restarting said engine when the detected voltage by said voltage detecting means shows a predetermined change mode for starting the welding operation; and an engine control circuit which stops said engine in response to said stop signal, and restarts said engine in response to said restart signal; wherein said direct-current power supply forms predetermined voltage output; wherein said restart detecting circuit forms said restart signal when said detected voltage shows the change mode corresponding to repetition of short-circuit and opening of said output terminals a predetermined number of times by contacting the welding rod with the base material; wherein said restart detecting circuit forms said restart signal when durations of short-circuit and opening of said output terminals and intervals of both of them are in predetermined ranges, and recognizes said predetermined change mode when the restart signal terminates with the last signal turning off the switch.