The invention relates to a method for
cutting a groove of a U-rib steel plate by
plasma cutting torches at double variable angles for one time. The method comprises steps as follows: two sets of
plasma batteries and two sets of the
plasma cutting torches which can deflect angles are mounted on one plasma
numerical control cutting
machine; the two
plasma cutting torches are configured with cutting
torch initial height positioners, cutting
torch arc voltage adjusting systems,
numerical control systems and PLC (
programmable logic controller) systems; a to-be-
cut steel plate is placed on a cutting table, the two
plasma cutting torches are aligned to the edge of the to-be-
cut steel plate, the transverse distance between the two
plasma cutting torches and the angles of the two plasma cutting torches are adjusted, and initial positioning values, cutting current and cutting speeds of the two plasma cutting torches are set in the
numerical control systems; and a starting button of the cutting
machine is pressed, and under the control of the numerical control systems, the two plasma cutting torches simultaneously start arc and
cut the U-rib steel plate. According to the method, only one
processing process is required, and the U-rib steel plate can be cut for one time, therefore, the operation is simple, automatic cutting is realized, and the straightness of the cut U-rib steel plate, the surface quality of the groove and the angle accuracy all meet the design requirements.