Gas discharge roll and manufacturing method for same, and processing apparatus using gas discharge roll

A gas discharge roll, comprising:

• an inner roll, which is made of metal, and has a rotary shaft in an end portion;
• an outer roll, which is made of metal with a cylindrical shape, and is fitted and integrated with an outer peripheral surface of the inner roll;
• gas introduction grooves, which are formed on the outer peripheral surface of the inner roll over an entire circumference thereof at substantially uniform intervals along a circumferential direction of the inner roll so as to extend along a rotary shaft direction of the inner roll, and which define gas introduction channels between an inner peripheral surface of the outer roll and the gas introduction grooves;
• and
• a group of gas discharge holes formed on the outer roll so as to penetrate through to the gas introduction channels,
• wherein the gas discharge roll has a porosity B within a gas introduction range of 20% or less,
• where the porosity B within a gas introduction range=(sectional area of the gas introduction channel×number of gas introduction channels)/(annular area surrounded by a maximum diameter circumference and a minimum diameter circumference sandwiching the gas introduction channel cross-section).

A method of manufacturing a gas discharge roll, the gas discharge roll including an inner roll, which is made of metal and has a rotary shaft in an end portion, and an outer roll, which is made of metal with a cylindrical shape and has an inner peripheral surface that is brought into contact with an outer peripheral surface of the inner roll, the gas discharge roll enabling a gas to be discharged to a surface of the outer roll,

• the method comprising:
• a groove forming step of forming a plurality of gas introduction grooves each extending in a rotary shaft direction on the outer peripheral surface of the inner roll over an entire circumference thereof at substantially uniform intervals;
• a shrink fitting step of shrink-fitting the outer roll with the outer peripheral surface of the inner roll having the plurality of gas introduction grooves formed thereon in the groove forming step;
• a joining step of joining the inner roll and the outer roll, which have been shrink-fitted with each other, by welding;
• and
• a hole forming step of forming a group of gas discharge holes on the outer roll, the group of gas discharge holes respectively penetrating through to a plurality of gas introduction channels defined between the plurality of gas introduction grooves formed on the outer peripheral surface of the inner roll and the inner peripheral surface of the outer roll,
• wherein the groove forming step is performed so that the gas discharge roll has a circumferential cutoff rate A of a gas introduction channel cross-section of 36% or less,
• where the circumferential cutoff rate A of a gas introduction channel cross-section=(maximum width in the circumferential direction of the gas introduction channel cross-section×number of gas introduction channels)/(minimum diameter circumference length cutting across a maximum width position in the circumferential direction of the gas introduction channel cross-section).

A method of manufacturing a gas discharge roll, the gas discharge roll including an inner roll, which is made of metal and has a rotary shaft in an end portion, and an outer roll, which is made of metal with a cylindrical shape and has an inner peripheral surface that is brought into contact with an outer peripheral surface of the inner roll, the gas discharge roll enabling a gas to be discharged to a surface of the outer roll,

• the method comprising:
• a groove forming step of forming a plurality of gas introduction grooves each extending in a rotary shaft direction on the outer peripheral surface of the inner roll over an entire circumference thereof at substantially uniform intervals;
• a shrink fitting step of shrink-fitting the outer roll with the outer peripheral surface of the inner roll having the plurality of gas introduction grooves formed thereon in the groove forming step;
• a joining step of joining the inner roll and the outer roll, which have been shrink-fitted with each other, by welding;
• and
• a hole forming step of forming a group of gas discharge holes on the outer roll, the group of gas discharge holes respectively penetrating through to a plurality of gas introduction channels defined between the plurality of gas introduction grooves formed on the outer peripheral surface of the inner roll and the inner peripheral surface of the outer roll,
• wherein the groove forming step is performed so that the gas discharge roll has a porosity B within a gas introduction range of 20% or less,
• where the porosity B within a gas introduction range=(sectional area of the gas introduction channel×number of gas introduction channels)/(annular area surrounded by a maximum diameter circumference and a minimum diameter circumference sandwiching the gas introduction channel cross-section).