Plasma processing device, plasma torch and method for replacing components of same

A plasma torch provided with a torch main unit having cooling water piping and plasma gas piping, and a detachable section installed detachably on said torch main unit;

• wherein said detachable section comprises:
• an electrode;
• a nozzle disposed in such a manner that it surrounds said electrode;
• an insulating member interposed between said electrode and said nozzle;
• and a retainer cap inside which said electrode, nozzle and insulating member are accommodated;
• said torch main unit comprises:
• an electrode connecting section for coupling with said electrode;
• a nozzle connecting section for coupling with said nozzle;
• and a retainer cap connecting section for coupling with said retainer cap;
• a coupling structure between said electrode and said electrode connecting section and a coupling structure between said nozzle and said nozzle connecting section being formed in such a manner that said electrode and said nozzle couple respectively with said electrode connecting section and said nozzle connecting section, when the operation of bringing said retainer cap close to said retainer cap connecting section along a predetermined path and coupling said retainer cap to said retainer cap connecting section is performed, and furthermore, said electrode and said nozzle detach respectively from said electrode connecting section and said nozzle connecting section, when the operation of detaching said retainer cap from said retainer cap connecting section and moving said retainer cap away from said retainer cap connecting section along a predetermined path is performed;
• said electrode, said insulating member, said nozzle, and said retainer cap coupling mutually, the respective coupling force therebetween being stronger than both the coupling force between said electrode and said electrode connecting section and the coupling force between said nozzle and said nozzle connecting section;
• whereby all the parts in said detachable section can be installed on said torch main unit and detached from said torch main unit, by installing said retainer cap on said retainer cap connecting section and detaching said retainer cap from said retainer cap connecting section.

A method for replacing consumable parts in a plasma torch:

• said plasma torch comprising a torch main unit having cooling water piping and plasma gas piping, and a detachable section installed detachably on said torch main unit;
• wherein said detachable section comprises:
• an electrode;
• a nozzle disposed in such a manner that it surrounds said electrode;
• an insulating member interposed between said electrode and said nozzle;
• and a retainer cap inside which said electrode, nozzle and insulating member are accommodated;
• and
• said torch main unit comprises:
• an electrode connecting section for coupling with said electrode;
• a nozzle connecting section for coupling with said nozzle;
• and a retainer cap connecting section for coupling with said retainer cap;
• said method comprising the steps of:
• removing all the parts in said detachable section, simultaneously, from said torch main unit, by detaching said retainer cap from said torch main unit of said plasma torch;
• exchanging said electrode or said nozzle in said detachable section for a new component;
• and
• attaching all the parts in said detachable section to said torch main unit, simultaneously, by attaching said retainer cap of said detachable section, wherein said electrode or said nozzle has been replaced for a new component, to said torch main unit, at said exchanging operation position.

A plasma torch comprising:

• an electrode for generating an arc;
• and
• an electrode seating for retaining said electrode by coupling detachably with said electrode, whilst also supplying an arc current to said electrode by connecting electrically to said electrode;
• wherein said electrode and said electrode seating respectively have electrical connection surfaces, said electrode and said electrode seating being electrically connected by means of said electrical connection surfaces making mutual contact;
• and
• said electrode seating comprises an elastic member which causes one of said electrical connection surfaces to press against the other on of said electrical connection surfaces, by means of elastic force generated by elastic deformation of said elastic member when said electrode is coupled with said electrode seating.

A plasma torch comprising a nozzle at the front end portion of the torch main unit, disposed in such a manner that it covers an electrode and separates said electrode from a plasma gas passage;

• comprising:
• a cylindrical guide made from insulating material which is fit between said electrode and said nozzle;
• a first elastic member, which is inserted between the outer circumference of said electrode and the inner circumference of said guide, in a continuous circumferential fashion or in a plurality of locations about the circumference thereof, and positions said electrode and said guide in the radial direction, by means of elastic expansion and contraction;
• and
• a second elastic member, which is inserted between the outer circumference of said guide and the inner circumference of said nozzle, in a continuous circumferential fashion or in a plurality of locations about the circumference thereof, and positions said guide and said nozzle in the radial direction, by means of elastic expansion and contraction.

A cylindrical guide made from insulating material which is fit between a nozzle and an electrode of a plasma torch;

• comprising:
• an inner circumference confronting the outer circumference of said electrode;
• and an outer circumference confronting the inner circumference of said nozzle;
• a first elastic member installing section provided on the inner circumference of said guide, for installing a first elastic member, which is interposed between the inner circumference of said guide and the outer circumference of said electrode and positions said electrode and said guide in the radial direction, by means of elastic expansion and contraction;
• and
• a second elastic member installing section provided on the outer circumference of said guide, for installing a second elastic member, which is interposed between the outer circumference of said guide and the inner circumference of said nozzle and positions said guide and said nozzle in the radial direction, by means of elastic expansion and contraction.

A cylindrical guide made from insulating material which is fit between a nozzle and an electrode of a plasma torch;

• comprising:
• an inner circumference confronting the outer circumference of said electrode;
• and
• having a clearance between the inner circumference of said guide and the outer circumference of said electrode, in order that positioning of said electrode and said guide in the radial direction can be performed by means of elastic expansion and contraction of an O-ring inserted therebetween.

A cylindrical guide made from insulating material which is fit between a nozzle and an electrode of a plasma torch;

• comprising:
• an outer circumference confronting the inner circumference of said nozzle;
• and
• having a clearance between the outer circumference of said guide and the inner circumference of said nozzle, in order that positioning of said guide and said nozzle in the radial direction can be performed by means of elastic expansion and contraction of an O-ring inserted therebetween.