Abstract: A joining device includes: an electrode for transmitting a current to an object to be joined; a current supply section for generating the current supplied to the object due to a voltage being applied thereto; a current measurement section for measuring the current supplied to the object; and a first control unit for correcting the voltage applied to the current supply section based on a current value measured before a last time by the current measurement section such that a current value measured by the current measurement section becomes a target current value. A method for manufacturing a joined object includes: supplying a current, which is generated by applying a voltage to a current supply section, to the object to be joined; measuring the current supplied to the object; and correcting the voltage applied to the current supply section based on a ratio between the measured current value and a desired current value.

Abstract: A joining device includes: a first circuit in which a primary-side winding of a first transformer and a first capacitor are connected; a second circuit in which a primary-side winding of a second transformer and a second capacitor are connected; an electrode connected to secondary-side winding of the first transformer and secondary-side winding of the second transformer; and a charge switch configured to switch between energization/de-energization of the first and second capacitors from a power supply without the transformers being interposed. The first circuit has a first discharge switch and the second circuit has a second discharge switch. A method for manufacturing a joined object includes, by using the joining device, supplying an object to be joined to be sandwiched by the electrode; causing a current to flow through the electrode that sandwiches the object to be joined to join the object to be joined.

Abstract: To provide a method and apparatus for manufacturing a joined member that inhibit occurrence of cracks in a joined member even when the joined portion is quenched when members are welded together. The method includes placing the first member D and the second member E with a joint target portion Df and a joint target portion Ef being in contact with each other, welding the joint target portions by heating, subjecting the first member D after the welding to a process for inhibiting occurrence of cracks, and tempering a portion where the first and second members have been welded to each other by electromagnetic heating.

Abstract: To provide a method and apparatus for manufacturing a joined member that inhibit occurrence of cracks in a joined member even when the joined portion is quenched when members are welded together. The method includes placing the first member D and the second member E with a joint target portion Df and a joint target portion Ef being in contact with each other, welding the joint target portions by heating, subjecting the first member D after the welding to a process for inhibiting occurrence of cracks, and tempering a portion where the first and second members have been welded to each other by electromagnetic heating.

Abstract: A method for manufacturing a joined article, the method including providing a first metal member E (ST1), providing a second metal member D, the second metal member D reaching a melting point before the first metal member E when the second metal member D is brought into contact with the first metal member E and an electric current is applied between the two metal members (ST2), preheating the first metal member E using a high-frequency induced electric current (ST3), applying pressure on the first metal member E and the second metal member D (ST4), applying an electric current between the first metal member E and the second metal member D at a timing at which a temperature of the first metal member E has reached a prescribed temperature TS4 due to the preheating (ST5), and joining the first and second metal members E and D through the application of pressure and the application of an electric current (ST4, ST5).

Abstract: A method for manufacturing a joined member and a joined member manufacturing apparatus which can manufacture a joined member with a joint portion having an appropriate hardness.

Abstract: A method for manufacturing a joined member and a joined member manufacturing apparatus which can manufacture a joined member with a joint portion having an appropriate hardness.

Abstract: To provide a metal bonded product wherein a large bonding area can be provided to achieve high bonding strength and coaxial accuracy can be easily achieved needing no positioning jig. A first taper portion 16 is formed on a side wall surface of the opening 13 of the ring-shaped metal member 12, and multiple step-shaped bonding surfaces are formed thereon. An end of the cylindrical portion 11 has a second taper portion 17 with the same chamfer angle as that of the first taper portion 16 of the ring-shaped metal member 12. The ring-shaped metal member 12 and the cylindrical metal member 11 are bonded to each other by press-fitting the cylindrical portion of the cylindrical metal member 11 in the opening 13 of the ring-shaped metal member 12 while applying a current to cause the side wall portion of the cylindrical portion of the cylindrical metal member 11 and the multiple step-shaped bonding surfaces of the first taper portion 16 to undergo plastic flow.

Abstract: An economical capacitor-type welding device and capacitor-type welding method that have a small power loss, that can be made compact, and that reliably control a charging circuit without being affected by the inductance of a charging path. In an exemplary capacitor-type welding device and an exemplary capacitor-type welding method of the invention, a bypass switching element having a forward-blocking function is connected in parallel to output terminals of a charging circuit, and the bypass switching element is brought into a conduction state to allow a backflow current, which is caused to flow by a magnetic energy stored in the inductance of a primary winding or an inductor included in the charging path, to bypass the charging circuit. A discharge switching element is brought into a conduction state after the bypass switching element enters the non-conduction state and recovers the forward-blocking function.

Abstract: To provide a method and apparatus for manufacturing a joined member that inhibit occurrence of cracks in a joined member even when the joined portion is quenched when members are welded together. The method includes placing the first member D and the second member E with a joint target portion Df and a joint target portion Ef being in contact with each other, welding the joint target portions by heating, subjecting the first member D after the welding to a process for inhibiting occurrence of cracks, and tempering a portion where the first and second members have been welded to each other by electromagnetic heating.

Abstract: A method for manufacturing a bonded article having long bonding length and high strength. A first bonding target member and a second bonding target member having a hole portion for receiving the first member are provided. Pressing force is applied between the two members with the first member received in the hole portion, and a current is applied to a bonding target portion between the two members with the pressing force applied. The two members are of materials with different melting points. One of the two members, having lower melting point, has a heat capacity increasing portion in the vicinity of the target portion. The one of the members has a taper face at the target portion, and the heat capacity increasing portion has a face extending from the taper face. The force applying step is performed with the other member positioned not to contact the heat capacity increasing portion.

Abstract: To provide a metal bonded product wherein a large bonding area can be provided to achieve high bonding strength and coaxial accuracy can be easily achieved needing no positioning jig. A first taper portion 16 is formed on a side wall surface of the opening 13 of the ring-shaped metal member 12, and multiple step-shaped bonding surfaces are formed thereon. An end of the cylindrical portion 11 has a second taper portion 17 with the same chamfer angle as that of the first taper portion 16 of the ring-shaped metal member 12. The ring-shaped metal member 12 and the cylindrical metal member 11 are bonded to each other by press-fitting the cylindrical portion of the cylindrical metal member 11 in the opening 13 of the ring-shaped metal member 12 while applying a current to cause the side wall portion of the cylindrical portion of the cylindrical metal member 11 and the multiple step-shaped bonding surfaces of the first taper portion 16 to undergo plastic flow.

Abstract: A method for manufacturing a bonded article having long bonding length and high strength. A first bonding target member and a second bonding target member having a hole portion for receiving the first member are provided. Pressing force is applied between the two members with the first member received in the hole portion, and a current is applied to a bonding target portion between the two members with the pressing force applied. The two members are of materials with different melting points. One of the two members, having lower melting point, has a heat capacity increasing portion in the vicinity of the target portion. The one of the members has a taper face at the target portion, and the heat capacity increasing portion has a face extending from the taper face. The force applying step is performed with the other member positioned not to contact the heat capacity increasing portion.

Abstract: The capacitive welder includes a charging circuit, a welding transformer, a capacitor, a discharging switching element connected in parallel with a primary winding of the welding transformer and the capacitor that are connected in series, a bypass switching element connected in parallel with the primary winding, welding electrodes connected in parallel with a secondary winding of the welding transformer, and a control circuit for bringing the welding transformer into a reset allowing state by allowing a reset current to flow in the primary winding using the input power introduced through the charging circuit without supplying an ON signal to the bypass switching element, and then supplying the ON signal to the bypass switching element such that the capacitor is charged through the bypass switching element by the input power introduced through the charging circuit.

Abstract: In order to achieve an object of stably joining two or more composite materials containing carbon fibers and a thermoplastic resin at a target joining position, joining surfaces of two or more composite materials (11a, 11b) containing carbon fibers and a thermoplastic resin are brought into contact, and an electric current for joining the two or more composite materials (11a, 11b) by Joule heat is fed to the target joining position in a state in which vibration is applied by a vibration generating device (17) to the two or more composite materials (11a, 11b) which are being pressed by a pressing device (13) so as to join the two or more composite materials (11a, 11b).

Abstract: The capacitive welder includes a charging circuit, a welding transformer, a capacitor, a discharging switching element connected in parallel with a primary winding of the welding transformer and the capacitor that are connected in series, a bypass switching element connected in parallel with the primary winding, welding electrodes connected in parallel with a secondary winding of the welding transformer, and a control circuit for bringing the welding transformer into a reset allowing state by allowing a reset current to flow in the primary winding using the input power introduced through the charging circuit without supplying an ON signal to the bypass switching element, and then supplying the ON signal to the bypass switching element such that the capacitor is charged through the bypass switching element by the input power introduced through the charging circuit.

Abstract: An economical capacitor-type welding device and capacitor-type welding method that have a small power loss, that can be made compact, and that reliably control a charging circuit without being affected by the inductance of a charging path. In an exemplary capacitor-type welding device and an exemplary capacitor-type welding method of the invention, a bypass switching element having a forward-blocking function is connected in parallel to output terminals of a charging circuit, and the bypass switching element is brought into a conduction state to allow a backflow current, which is caused to flow by a magnetic energy stored in the inductance of a primary winding or an inductor included in the charging path, to bypass the charging circuit. A discharge switching element is brought into a conduction state after the bypass switching element enters the non-conduction state and recovers the forward-blocking function.