Abstract: A center pipe is used in a plasma torch including a base portion and an electrode to supply cooling water into the electrode. The center pipe includes a pipe body and a contact piece. The pipe body has a tube-like shape with a cooling water channel therein. The pipe body is electrically conductive and configured to be electrically connected to an external power source via the base portion. The contact piece is arranged radially outside the pipe body at an intermediate position between a base end surface and a tip end surface of the pipe body. The contact piece is electrically conductive and energizes the electrode through contact with an internal circumferential surface of the electrode. The base end surface is disposed outside the electrode when the center pipe is inserted into the electrode. The pipe body is configured to be electrically connected to the electrode via the contact piece.

Abstract: A center pipe is used in a plasma torch for plasma cutting including a base portion and an electrode. The center pipe is inserted into the electrode and supplies cooling water into the electrode. The center pipe includes a pipe body and a contact piece. The pipe body is electrically connected to an electrical power source outside of the plasma torch via the base portion. The pipe body includes a cooling water channel therein. The pipe body is formed with an electrically conductive body. The contact piece is provided on the external circumferential surface of the pipe body and energizes the electrode through contact with the internal circumferential surface of the electrode. The contact piece has elasticity to produce a counterforce when pressed in the radial direction of the pipe body. The contact piece is formed with an electrically conductive body.

Abstract: A center pipe is used in a plasma torch for plasma cutting including a base portion and an electrode. The center pipe is inserted into the electrode and supplies cooling water into the electrode. The center pipe includes a pipe body and a contact piece. The pipe body is electrically connected to an electrical power source outside of the plasma torch via the base portion. The pipe body includes a cooling water channel therein. The pipe body is formed with an electrically conductive body. The contact piece is provided on the external circumferential surface of the pipe body and energizes the electrode through contact with the internal circumferential surface of the electrode. The contact piece has elasticity to produce a counterforce when pressed in the radial direction of the pipe body. The contact piece is formed with an electrically conductive body.

Abstract: A resin insulation guide is used in a plasma torch including an electrode and a nozzle into which the electrode is inserted. The insulation guide is used to couple the electrode and the nozzle, and includes a first internal circumferential surface formed on an inside of the insulation guide, a second internal circumferential surface formed on the inside of the insulation guide, a communication channel, and a heat resistant coating formed on the first internal circumferential surface. The second internal circumferential surface has an inner diameter smaller than an inner diameter of the first internal circumferential surface. The communication channel communicates a space inside the first internal circumferential surface to an outside of the insulation guide, and extends in a direction inclined with respect to an axial direction of the insulation guide.

Abstract: A replacement part unit for a plasma torch includes an electrode, an insulation guide, and a nozzle. The insulation guide includes a hole into which the electrode is inserted. The insulation guide is coupled to the electrode by press-fitting or adhesion. The nozzle includes a hole into which the insulation guide is inserted. The nozzle is coupled to the insulation guide by press-fitting or adhesion.

Abstract: A method of cutting a cut member out of an original sheet by means of thermal cutting and machining, and includes a hole-cutting process, a finishing process, and an outer periphery-cutting process. During the hole-cutting process, a hole is created in the original sheet by means of thermal cutting while leaving a machining allowance in addition to the finished size of the hole. During the finishing process, a cutting tool is inserted into the hole which has been created through the hole-cutting process, and the cutting tool is guided along the inner circumference of the hole so as to cut the thermally-cut end surface in order to machine the hole to the finished size. During the outer periphery-cutting process, the outer periphery of the cut member is cut by means of thermal cutting to take the cut member out of the original sheet.

Abstract: A method of cutting a cut member out of an original sheet by means of thermal cutting and machining, and includes a hole-cutting process, a finishing process, and an outer periphery-cutting process. During the hole-cutting process, a hole is created in the original sheet by means of thermal cutting while leaving a machining allowance in addition to the finished size of the hole. During the finishing process, a cutting tool is inserted into the hole which has been created through the hole-cutting process, and the cutting tool is guided along the inner circumference of the hole so as to cut the thermally-cut end surface in order to machine the hole to the finished size. During the outer periphery-cutting process, the outer periphery of the cut member is cut by means of thermal cutting to take the cut member out of the original sheet.