Electrode orientation checking apparatus and electrode orientation checking method

An electrode orientation checking method that, for a seam welding apparatus that performs seam welding by sandwiching a stacked body comprising a plurality of stacked workpieces between a first roller electrode and a second roller electrode, checks an orientation of the first roller electrode and the second roller electrode to the stacked body, the electrode orientation checking method comprising:

• a fixing step of detachably attaching a machine stand that includes a positioning guide to the seam welding apparatus from which the first roller electrode has been removed, and fixing a positioning surface of the positioning guide at a position that, when the stacked body is sandwiched between the first roller electrode before being removed and the second roller electrode, corresponds to a portion of an outer circumferential surface of the first roller electrode, the portion lying on a line segment connecting rotational centers of the first roller electrode and the second roller electrode;
• a detection step of, with a set of distance sensors provided on the machine stand and respectively fixed farther forward than the positioning surface and farther backward than the positioning surface in a progression direction of the first roller electrode relative to the stacked body, detecting a distance, along an extension direction of the line segment, to the stacked body sandwiched by the positioning surface and the second roller electrode;
• and
• a calculation step of calculating data for acquiring a direction of the line segment relative to the stacked body, based on detection results of the set of distance sensors.