Laser welding method for electrical wire connection to a terminal pin of an exhaust gas sensor
AssigneeFord Motor Company
InventorsUck I. Chang, Kenneth W. Casey
Life of this patent
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Abstract
A method for welding an electrical lead wire to a terminal pin with the use of a laser beam. The method is particularly designed for use in welding an electrical lead wire of an exhaust gas sensor to a terminal pin having an opening through which the electrical lead wire extends to the exterior of the pin. The lead wire may be made of nichrome material and the terminal pin from leaded steel. The laser beam is positioned vertically above the extended portion of the lead wire and its focal point is above the end of the lead wire. No separate filler metal is required since the lead wire material is itself available as a filler material.
Claims11
A method for welding an electrical lead wire to a terminal pin, the terminal pin having a head with an internal opening, the electrical lead wire being received within the opening and having a portion extending to the exterior of the terminal-pin head, the method comprising the steps of:
- (a) supporting the terminal pin with the head thereof being located such that the portion of the electrical lead wire extending therefrom is substantially vertical and the exterior portion of the lead wire has its end terminating a predetermined distance above the terminal-pin head;
- (b) positioning a laser beam source above the exterior portion of the lead wire;
- (c) causing the laser beam from the source to be propagated in a direction substantially coinciding with the force of gravity, the laser beam having a focal point located above the electrical lead wire end and the laser beam impinging on the end of the electrical lead wire and on the head of the terminal pin;
- and
- (d) applying the laser beam to the electrical lead wire and terminal-pin head, as specified in step (c) above, for a time period sufficient to enable the end of the electrical lead wire to liquify, to progressively move in the liquified state toward the terminal-pin head, and thereafter to coalesce with metal in the terminal-pin head concurrently liquified by the laser beam.
Dependencies are inferred from the claim text.