Abstract: The Present invention provides an arc melting furnace apparatus and a method of controlling arc discharge, in which a melt material having been melted can be stirred efficiently, avoiding labor intensive work. The furnace is provided with a mold 3 having a recess 3a and provided in a melting chamber 2, a non-consumable discharge electrode 5 for heating and melting a melt material accommodated in the recess 3a, a power source unit 10 for supplying electric power to the non-consumable discharge electrode 5, and a control device 11 which controls the power source unit to control output intensity of the arc discharge from the non-consumable discharge electrode. The control device 11 controls output current from the power source unit 10 and its current frequency to vary the output intensity of the arc discharge from the non-consumable discharge electrode 5 and stir a molten metal resulting from heating and melting the melt material.

Abstract: An arc melting furnace apparatus is provided which reduces an operation burden on a worker and shortens working hours. An arc melting furnace apparatus 1 includes a housing 2 having formed therein a melting chamber 2a, a hearth 4 provided within the melting chamber 2a and having a recessed portion 4a, and a heating mechanism 10 for heating and melting a metal material supplied into the recessed portion 4 to generate an alloy ingot. The apparatus comprises a turning member 23 rotatably supported on a supporting member 21 standing within the melting chamber 2a, a perimeter edge of the turning member 23 rotating and moving along the inner surface of the recessed portion 4a to lift the alloy ingot generated in the recessed portion 4a above the hearth 4 and turn it over, and a resilient turn-over assisting member 24 provided above an upper end of the recessed portion 4a.

Abstract: In a screw fluid machine including male and female rotors which are engaged with each other, a casing for accommodating both the male and female rotors, fluid working rooms which are formed by the male and female rotors and the casing, and fluid inlet and outlet ports which are provided in the casing so as to intercommunicate with one end portion and the other end portion of the working rooms, the helix angle of the screw gear constituting each of the male and female rotors is set to be continuously varied in a helix advance direction. Further, the screw gear is designed so that the peripheral length of a pitch cylinder in a helix advance direction on a development of a tooth-trace rolling curve on the pitch cylinder of the screw gear can be expressed by a substantially monotonically increasing function.

Abstract: In a screw fluid machine including male and female rotors which are engaged with each other, a casing for accommodating both the male and female rotors, fluid working rooms which are formed by the male and female rotors and the casing, and fluid inlet and outlet ports which are provided in the casing so as to intercommunicate with one end portion and the other end portion of the working rooms, the helix angle of the screw gear constituting each of the male and female rotors is set to be continuously varied in a helix advance direction. Further, the screw gear is designed so that the peripheral length of a pitch cylinder in a helix advance direction on a development of a tooth-trace rolling curve on the pitch cylinder of the screw gear can be expressed by a substantially monotonically increasing function.

Abstract: In a screw fluid machine including male and female rotors which are engaged with each other, a casing for accommodating both the male and female rotors, fluid working rooms which are formed by the male and female rotors and the casing, and fluid inlet and outlet ports which are provided in the casing so as to intercommunicate with one end portion and the other end portion of the working rooms, the helix angle of the screw gear constituting each of the male and female rotors is set to be continuously varied in a helix advance direction. Further, the screw gear is designed so that the peripheral length of a pitch cylinder in a helix advance direction on a development of a tooth-trace rolling curve on the pitch cylinder of the screw gear can be expressed by a substantially monotonically increasing function.