Patent ID: 7972198

Claim:
A groove machining method which machines a complex groove pattern of intersecting grooves on a face of a workpiece, the grooves having defined ends in the direction of the length of the grooves, using a water jet device including an injection nozzle for injecting a water jet on a face to be machined of a member to be machined, comprising: a first disposing step of disposing a first protection member, which is more resistive against an injection power of the water jet than the member to be machined, at a first position so as to cover a portion of the face to be machined in a first groove machining step, and on which grooves are not to be formed in the first groove machining step; a first moving step of moving the injection nozzle in a first direction across the protection member and the face to be machined while injecting the water jet at a predetermined injection power from the injection nozzle, to perform the first groove machining step in which first grooves are formed in the face to be machined, the first grooves having at least one end defined by the protection member at said first position; a step of removing the first protection member from the member to be machined; a second disposing step of disposing a second protection member which, is more resistive against an injection power of the water jet than the member to be machined, at a second position different from said first position so as to cover a portion of said face to be machined in a second groove machining step, and on which grooves are not to be formed in the second groove machining step, wherein the portion to be machined in the second groove machining step is different from the portion to be machined in the first groove machining step; and a second moving step of moving the injection nozzle in a second direction across the protection member and the face to be machined while injecting the water jet at a predetermined injection power from the injection nozzle, to perform the second machining step in which second grooves are formed in the face to be machined, the second grooves intersecting with the first grooves and each of the second grooves having at least one end defined by the protection member at said second position, wherein the second direction is different from the first direction.