An electrostatic energy storage welding machine for performing resistance welding while applying pressure to an object to be welded includes: a pair of welding electrodes; an energy storage section including a plurality of energy storage parts; an individual charge circuit for individually charging respective energy storage parts; an individual discharge circuit for individually discharging the respective energy storage parts; a voltage monitor circuit individually monitoring voltages of the respective energy storage parts; an individual voltage stabilization control section for performing control to further charge an energy storage part having deviation in performance in an individual manner to stabilize a voltage of that energy storage part and thereby achieve a set voltage; and an output circuit for outputting power produced by the set voltage stabilized through individual charging and electric current through individual discharging in the energy storage section to apply the electric current between the welding electrodes.

A sealing method that uses an electrostatic energy storage welding machine which includes an energy storage section including a plurality of energy storage parts is provided. A method of sealing a liquid inlet port of a power storage device includes burring in advance a through-hole of the liquid sealing port to raise a hole edge of the through-hole into a form of a projection, wherein the liquid sealing port of the power storage device to be sealed with electrolyte contained therein corresponds to an object to be welded; placing a spherical body that is a lid body on the projection; and performing resistance welding between the projection and the spherical body to seal the liquid inlet port.

A sealing method that uses an electrostatic energy storage welding machine which includes an energy storage section including a plurality of energy storage parts is provided. A method of sealing a liquid inlet port of a power storage device includes burring in advance a through-hole of the liquid sealing port to raise a hole edge of the through-hole into a form of a projection, wherein the liquid sealing port of the power storage device to be sealed with electrolyte contained therein corresponds to an object to be welded; placing a spherical body that is a lid body on the projection; and performing resistance welding between the projection and the spherical body to seal the liquid inlet port.

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.

A method of joining a first piece of an automotive component that is made from a first material to a second piece of the automotive component that is made from a second material includes machining a fay surface onto each of the first and second pieces of the automotive component, cleaning the fay surfaces of each of the first and second pieces of the automotive component, placing a metal filler between the fay surfaces of the first and second pieces of the automotive component, holding the first and second pieces together with the metal filler positioned between the fay surfaces of the first and second pieces, and passing an electric current through the first piece, the metal filler and the second piece to melt the metal filler and weld the first piece to the second piece.

A method of joining a first piece of an automotive component that is made from a first material to a second piece of the automotive component that is made from a second material includes machining a fay surface onto each of the first and second pieces of the automotive component, cleaning the fay surfaces of each of the first and second pieces of the automotive component, placing a metal filler between the fay surfaces of the first and second pieces of the automotive component, holding the first and second pieces together with the metal filler positioned between the fay surfaces of the first and second pieces, and passing an electric current through the first piece, the metal filler and the second piece to melt the metal filler and weld the first piece to the second piece.

A method of joining parts, where at least one of the parts has a faying surface defining grooves therein. One of the parts is formed of a majority of titanium, and the other part is formed of a majority of iron. The method includes providing a set of opposed welding electrodes disposed on a side of each part and applying pressure to and heating the parts via the set of electrodes to form a joint between the parts. A bonded assembly includes a first part formed of a majority of titanium and a second part formed of a steel alloy. The first and second parts having a bond that includes a portion of the first part directly in contact with and attached to a portion of the second part. The parts may be a titanium-containing differential carrier case bonded to a steel gear.

A method of joining parts, where at least one of the parts has a faying surface defining grooves therein. One of the parts is formed of a majority of titanium, and the other part is formed of a majority of iron. The method includes providing a set of opposed welding electrodes disposed on a side of each part and applying pressure to and heating the parts via the set of electrodes to form a joint between the parts. A bonded assembly includes a first part formed of a majority of titanium and a second part formed of a steel alloy. The first and second parts having a bond that includes a portion of the first part directly in contact with and attached to a portion of the second part. The parts may be a titanium-containing differential carrier case bonded to a steel gear.

A method of joining a first piece of an automotive component that is made from a first material to a second piece of the automotive component that is made from a second material includes machining a fay surface onto each of the first and second pieces of the automotive component, cleaning the fay surfaces of each of the first and second pieces of the automotive component, placing a metal filler between the fay surfaces of the first and second pieces of the automotive component, holding the first and second pieces together with the metal filler positioned between the fay surfaces of the first and second pieces, and passing an electric current through the first piece, the metal filler and the second piece to melt the metal filler and weld the first piece to the second piece.

A method of joining a first piece of an automotive component that is made from a first material to a second piece of the automotive component that is made from a second material includes machining a fay surface onto each of the first and second pieces of the automotive component, cleaning the fay surfaces of each of the first and second pieces of the automotive component, placing a metal filler between the fay surfaces of the first and second pieces of the automotive component, holding the first and second pieces together with the metal filler positioned between the fay surfaces of the first and second pieces, and passing an electric current through the first piece, the metal filler and the second piece to melt the metal filler and weld the first piece to the second piece.