Abstract: A metal pipe forming method includes: disposing a metal pipe material having a hollow shape between a pair of dies; and forming a metal pipe including a pipe portion and a flange portion by expanding the metal pipe material by supplying a fluid and bringing the metal pipe material into contact with the pair of dies. In the forming of the metal pipe, a gap which is positioned between a pair of inner surfaces of the flange portion and communicates with an internal space of the pipe portion is formed, and the flange portion is provided with a through-hole connected to the gap.

Abstract: A forming system includes a heating unit that causes a current to flow through a plated metal material to heat the metal material, a forming die that forms the heated metal material, and a plating deviation suppression mechanism that suppresses a deviation of a plating in the metal material due to energization heating.

Abstract: An arc welder includes a welding power supply, a forward/reverse welding wire feeder, and a controller for the power supply and the wire feeder. Welding is implemented by repeating unit welding steps each including a short circuit stage with the welding wire and a base material being short-circuited and an arc stage with an arc being generated between the wire and the material. A transition period continues from a starting point of the arc stage till the wire feeding rate reaches a forward maximum. An average welding current is defined as an average of the welding current during the short circuit and arc stages. Within the transition period, the controller sets a current suppression period during which welding current is smaller than the average welding current. Transition period length T0 and current suppression period length T1 are set to satisfy the inequality 0<T1/T0?0.8.

Abstract: A treatment device that performs treatment for forming a plating layer on a metal pipe material that is used as a material for hot forming, the treatment device includes a supply unit that supplies a plating material to an inner periphery-side surface of a welded portion formed in the metal pipe material.

Abstract: A forming device is a forming device that forms a metal pipe with a flange and includes a forming tool for forming the metal pipe, in which the forming tool includes a first die and a second die that face each other in a first direction in a cross-sectional view, and a third die for regulating a planned flange portion of a metal pipe material, and the third die continues to correct misalignment of the planned flange portion until the first die and the second die are clamped.

Abstract: A forming device which expands a metal pipe material to form a metal pipe having a pipe portion and a flange portion includes first and second dies paired with each other and including pipe forming surfaces for forming the pipe portion and flange forming surfaces for forming the flange portion, a drive unit that drives at least one of the first and second dies, and a controller that controls the drive unit, in which, on at least one of the flange forming surfaces of the first and second dies, a protrusion portion protruding by an amount not to abut against the other flange forming surface when the dies are closed is formed and the controller controls the drive unit to form a thin wall portion at which a thickness of the flange portion becomes partially small at the flange portion by the protrusion portion pressing the flange portion.

Abstract: A forming system forming a metal pipe by expanding a metal pipe material, includes: a main body part having a forming die for forming the metal pipe; an electrode causing a current to flow through the metal pipe material disposed in the forming die such that the metal pipe material is heated; a power supply unit disposed at a position separated from the main body part and supplying power to the electrode; and a power supply line connecting the power supply unit and the electrode, in which the power supply line includes a lower-side passing portion passing through a lower side of a placing surface on which the main body part is placed, a first connection portion drawn to an upper side of the placing surface and connecting the lower-side passing portion and the electrode, and a second connection portion connecting the lower-side passing portion and the power supply unit.

Abstract: A forming device which expands a metal pipe material to form a metal pipe having a pipe portion and a flange portion includes a hardness lowering portion which lowers a hardness of the flange portion to be lower than a hardness of the pipe portion.

Abstract: A forming apparatus which forms a metal pipe by expanding a metal pipe material, includes: a forming die for forming the metal pipe; a first electrode and a second electrode which clamp the metal pipe material at both end sides and heat the metal pipe material by causing an electric current to flow through the metal pipe material; and a first fluid supply unit and a second fluid supply unit which supply a fluid into the metal pipe material heated by the first electrode and the second electrode to expand the metal pipe material, wherein at least one of the first electrode and the second electrode is provided with a movement restriction mechanism which restricts a movement of the metal pipe material in an axial direction of the metal pipe material.

Abstract: A forming apparatus that forms a metal pipe material includes an electrode that holds the metal pipe material and supplies electric power to the metal pipe material to heat the metal pipe material, a forming die that quenches and forms the expanded metal pipe, and a member that suppresses quenching, in which a region where quenching is not performed in the metal pipe is adjusted by adjusting a length of the member.

Abstract: A metal pipe forming method includes: disposing a metal pipe material having a hollow shape between a pair of dies; and forming a metal pipe including a pipe portion and a flange portion by expanding the metal pipe material by supplying a fluid and bringing the metal pipe material into contact with the pair of dies. In the forming of the metal pipe, a gap which is positioned between a pair of inner surfaces of the flange portion and communicates with an internal space of the pipe portion is formed, and the flange portion is provided with a through-hole connected to the gap.

Abstract: A forming system for forming a metal pipe having a hollow shape includes a forming apparatus including a gas supply portion that supplies gas into a heated metal pipe material when forming the metal pipe, and a discharge unit that discharges the gas into the formed metal pipe, in which an exhaust port of the discharge unit is positioned in an internal space of a structure including the internal space.

Abstract: There is provided an arc welding control method of performing a forward/reverse feeding control of alternating a feeding rate of a welding wire between a forward feeding period and a reverse feeding period, and generating short-circuiting periods and arc periods to perform welding. The welding wire is fed forwardly at a time of staring the welding. The forward/reverse feeding control is started from the reverse feeding period of the welding wire after starting conduction of a welding current.

Abstract: A forming device which expands a metal pipe material to form a metal pipe having a pipe portion and a flange portion includes first and second dies paired with each other and including pipe forming surfaces for forming the pipe portion and flange forming surfaces for forming the flange portion, a drive unit that drives at least one of the first and second dies, and a controller that controls the drive unit, in which, on at least one of the flange forming surfaces of the first and second dies, a protrusion portion protruding by an amount not to abut against the other flange forming surface when the dies are closed is formed and the controller controls the drive unit to form a thin wall portion at which a thickness of the flange portion becomes partially small at the flange portion by the protrusion portion pressing the flange portion.

Abstract: A forming device which expands a metal pipe material to form a metal pipe having a pipe portion and a flange portion includes a hardness lowering portion which lowers a hardness of the flange portion to be lower than a hardness of the pipe portion.

Abstract: An electrical heating apparatus for supplying electric power to a metal body to electrically heat the metal body, includes: at least two electrodes that come into contact with the metal body; a power supply unit that supplies electric power to the electrodes; a warning unit that issues a warning that abnormality has occurred in the electrical heating of the metal body; and an abnormality detection unit that detects abnormality of the electrodes, in which the abnormality detection unit includes a resistance value acquisition unit that acquires a resistance value between the electrodes, and an abnormality determination unit that determines that abnormality has occurred in the electrodes and controls the warning unit to issue a warning that abnormality has occurred in the electrodes, in a case where the resistance value reaches a predetermined setting value.

Abstract: There is provided an arc welding control method of alternating a feeding rate of a welding wire between a forward feeding period and a reverse feeding period, controlling a welding voltage based on a voltage setting value and alternating short-circuiting periods and arc periods to perform welding. In the arc welding control method a cycle of the feeding rate is changed based on the voltage setting value.

Abstract: A forming apparatus which forms a metal pipe by expanding a metal pipe material, includes: a forming die for forming the metal pipe; a first electrode and a second electrode which clamp the metal pipe material at both end sides and heat the metal pipe material by causing an electric current to flow through the metal pipe material; and a first fluid supply unit and a second fluid supply unit which supply a fluid into the metal pipe material heated by the first electrode and the second electrode to expand the metal pipe material, wherein at least one of the first electrode and the second electrode is provided with a movement restriction mechanism which restricts a movement of the metal pipe material in an axial direction of the metal pipe material.

Abstract: There is provided an arc welding control method of feeding a welding wire according to a push-pull feeding control using a push-side feeding motor which rotates in a forward feeding direction at a feeding rate set to a push feeding-rate setting value and a pull-side feeding motor which alternates a forward feeding rotation and a reverse feeding rotation periodically, and generating short-circuiting periods and arc periods to perform welding. An average feeding rate of the pull-side feeding motor is detected. The push feeding-rate setting value is corrected to the detected average feeding rate of the pull-side feeding motor.

Abstract: A forming system forming a metal pipe by expanding a metal pipe material, includes: a main body part having a forming die for forming the metal pipe; an electrode causing a current to flow through the metal pipe material disposed in the forming die such that the metal pipe material is heated; a power supply unit disposed at a position separated from the main body part and supplying power to the electrode; and a power supply line connecting the power supply unit and the electrode, in which the power supply line includes a lower-side passing portion passing through a lower side of a placing surface on which the main body part is placed, a first connection portion drawn to an upper side of the placing surface and connecting the lower-side passing portion and the electrode, and a second connection portion connecting the lower-side passing portion and the power supply unit.