Abstract: A joint method includes a groove formation step of removing part of a first projection and part of the second projection to form a groove region between the first projection and the second projection, a first welding step of joining a first member and a second member to each other by butt welding, and a second welding step of filling the groove region by buildup welding. The groove formation step forms a first inclined surface in the first projection facing the groove region to be gradually distant from a joint position joined with the second projection so as to be closer to an outer surface of the first projection, and forms a second inclined surface in the second projection facing the groove region to be gradually distant from the joint position joined with the first projection so as to be closer to an outer surface of the second projection.

Abstract: A converter blowing control method includes: calculating, by heat balance calculation and material balance calculation, an amount of oxygen supplied and an amount of a cooling material or a rising heat material charged to control a temperature and a component concentration of molten steel at end of blowing in a converter to target values; controlling the blowing in the converter based on the calculated amount of oxygen supplied and the calculated amount of a cooling material or a rising heat material charged; estimating a pre-blowing molten iron temperature that is a temperature of molten iron used as a raw material for blowing to be a target of the heat balance calculation, charged into the converter, and is in a state immediately before start of the blowing; and using the estimated pre-blowing molten iron temperature as a charged molten iron temperature in the heat balance calculation.

Abstract: A converter blowing control method includes: calculating, by heat balance calculation and material balance calculation, an amount of oxygen to be supplied and an amount of a cooling material or a rising heat material to be charged for controlling a temperature and a component concentration of molten steel at end of blowing in a converter to target values; and controlling the blowing in the converter based on the calculated amount of oxygen to be supplied and the calculated amount of a cooling material or a rising heat material to be charged. A temperature of molten iron is used as a raw material for blowing, which is a target of the heat balance calculation, is used as a charged molten iron temperature used in the heat balance calculation, the temperature of molten iron being measured during a period when the molten iron is charged into the converter.

Abstract: A joint method includes a groove formation step of removing part of a first projection and part of the second projection to form a groove region between the first projection and the second projection, a first welding step of joining a first member and a second member to each other by butt welding, and a second welding step of filling the groove region by buildup welding. The groove formation step forms a first inclined surface in the first projection facing the groove region to be gradually distant from a joint position joined with the second projection so as to be closer to an outer surface of the first projection, and forms a second inclined surface in the second projection facing the groove region to be gradually distant from the joint position joined with the first projection so as to be closer to an outer surface of the second projection.

Abstract: A method of forming stiffened plate by welding a plurality of stiffener materials and a steel plate, so that closed cross-sectional structures are secured onto a surface of the steel plate. The stiffener materials are joined to the steel plate as a result of edge portions of the stiffener materials which are in contact with the steel plate by being laser welded at a predetermined welding speed as a result of a laser having a predetermined output being irradiated from a predetermined direction thereon from the external side of the closed cross-sectional structures. Accordingly, it is possible to achieve an improvement in the weld quality when welding stiffener materials onto a steel plate, and to achieve an improvement in fatigue strength.

Abstract: A method of forming stiffened plate by welding a plurality of stiffener materials and a steel plate, so that closed cross-sectional structures are secured onto a surface of the steel plate. The stiffener materials are joined to the steel plate as a result of edge portions of the stiffener materials which are in contact with the steel plate by being laser welded at a predetermined welding speed as a result of a laser having a predetermined output being irradiated from a predetermined direction thereon from the external side of the closed cross-sectional structures. Accordingly, it is possible to achieve an improvement in the weld quality when welding stiffener materials onto a steel plate, and to achieve an improvement in fatigue strength.

Abstract: In a motor control apparatus, apparatus all switching devices of all phases of an inverter are kept fixed at OFF in accordance with a value of an all-OFF control pulse signal Poff outputted by a pulse generator. The pulse generator generates at least twice a pulse causing an induced voltage detection signal Pdet to change to an H level. A terminal voltage of a motor is inputted in accordance with the value of the induced voltage detection signal Pdet. Data of the sampling round in which amplitude of the induced voltage signal is great and the signal is not in saturation is selected from the data so inputted and a rotor position is estimated.

Abstract: A stiffened plate is formed by welding a plurality of stiffener materials which, together with a steel plate, form closed cross-sectional structures onto a surface of the steel plate. The stiffener materials are joined to the steel plate as a result of edge portions of the stiffener materials which are in contact with the steel plate by being laser welded at a predetermined welding speed as a result of a laser having a predetermined output being irradiated from a predetermined direction thereon from the external side of the closed cross-sectional structures. Accordingly, it is possible to achieve an improvement in the weld quality when welding stiffener materials onto a steel plate, and to achieve an improvement in fatigue strength.

Abstract: In a motor control apparatus, apparatus all switching devices of all phases of an inverter are kept fixed at OFF in accordance with a value of an all-OFF control pulse signal Poff outputted by a pulse generator. The pulse generator generates at least twice a pulse causing an induced voltage detection signal Pdet to change to an H level. A terminal voltage of a motor is inputted in accordance with the value of the induced voltage detection signal Pdet. Data of the sampling round in which amplitude of the induced voltage signal is great and the signal is not in saturation is selected from the data so inputted and a rotor position is estimated.

Abstract: An electromagnetic operation device, comprising electromagnetic operators each paired with a vacuum valve of each phase of three phases, is equipped with main shafts that can operate independently for each phase and a three-phase connecting shaft that synchronizes the operation of the three phases in accordance with the operation of each main shaft. The rod of the electromagnetic operator is connected with the blade of the main shaft at the fulcrum and the blade of the three-phase connecting shaft is connected with the blade of the main shaft by the linkage. The motion of a main shaft that has operated quicker than the others is transmitted to the other main shafts via the three-phase connecting shaft so as to synchronize the operation of the three phases.