Patent ID: 7087855

Claim:
A plasma cutting apparatus for cutting a product from a plate material by moving a plasma torch at a cutting speed along a cutting path corresponding to the product shape to cut said plate material, while supplying an arc current and a plasma gas to said plasma torch and forming a plasma arc from a nozzle of said plasma torch to the plate material, said plasma cutting apparatus comprising a control unit for controlling a cutting state including said cutting speed, a value of said arc current, and a flow rate or pressure of said plasma gas, wherein said control unit conducts control so that, when the shape of said product comprises a hole and a contour and when said hole is cut, said cutting speed is lower, a value of said arc current is smaller, and a flow rate or pressure of said plasma gas is less than those when said contour is cut, wherein when said hole is cut, said control unit controls said cutting state according to a ratio of the plate thickness of said plate material and the diameter of said hole.