A method for welding multiple workpieces together includes applying a force to the multiple workpieces, generating ultrasonic vibration, transferring the ultrasonic vibration to the multiple workpieces to breakdown an oxide layer, generating an electric current, transmitting the electric current to heat up the workpieces, and synchronizing the ultrasonic and resistance heating operations. A welding system includes an ultrasonic vibration unit that generates an ultrasonic vibration and transfers the ultrasonic vibration to multiple workpieces to breakdown an oxide layer, a resistance heating unit that generates an electric current and transmits the electric current to heat up the workpieces, a workpiece mount that includes electrodes configured to receive the generated current and/or clamp the multiple workpieces during a welding process, and a controller configured to synchronize an operation of the ultrasonic vibration unit and an operation of a resistance heating unit.

A welding electrode for an electric resistance welding process. The welding electrode includes a body extending along a center axis and terminating axially at a weld face for contacting a work face. The weld face defines a center along the axis and defines an outer edge spaced radially from the center. A plurality of senates are defined along the weld face. Each of the serrates projects axially away from the weld face and extends radially from the center axis to the outer edge of the weld face. A higher density of the plurality of serrates is formed proximate to the center axis than proximate to the outer circumference of the weld face. Methods for using the welding electrode and forming the senates on the welding electrode are also provided.

A welding electrode for an electric resistance welding process. The welding electrode includes a body extending along a center axis and terminating axially at a weld face for contacting a work face. The weld face defines a center along the axis and defines an outer edge spaced radially from the center. A plurality of senates are defined along the weld face. Each of the serrates projects axially away from the weld face and extends radially from the center axis to the outer edge of the weld face. A higher density of the plurality of serrates is formed proximate to the center axis than proximate to the outer circumference of the weld face. Methods for using the welding electrode and forming the senates on the welding electrode are also provided.

An ultrasonic resistance welding apparatus 10 contains a resistance spot welding apparatus 15, a first electrode 16 and a vibrable second electrode 18, the vibrable second electrode 18 in operable communication with an ultrasonic transducer 12, whereby the ultrasonic transducer 12 selectively imparts vibratory energy to the vibrable second electrode 18 based on signals from a controller 32. The vibrable second electrode 18 may be tuned or designed to resonate within 2.5% of an operating frequency of the ultrasonic transducer 12. During operation of the welding apparatus 10, a tip 19 of the second vibrable electrode 18 may be positioned at an anti-nodal point 38 of the vibratory energy and the vibrable second electrode 18 may be attached to the resistance spot welding apparatus 15 at a nodal plane 36 of the vibratory energy. A process for employing the apparatus 10 is also presented.

An ultrasonic resistance welding apparatus 10 contains a resistance spot welding apparatus 15, a first electrode 16 and a vibrable second electrode 18, the vibrable second electrode 18 in operable communication with an ultrasonic transducer 12, whereby the ultrasonic transducer 12 selectively imparts vibratory energy to the vibrable second electrode 18 based on signals from a controller 32. The vibrable second electrode 18 may be tuned or designed to resonate within 2.5% of an operating frequency of the ultrasonic transducer 12. During operation of the welding apparatus 10, a tip 19 of the second vibrable electrode 18 may be positioned at an anti-nodal point 38 of the vibratory energy and the vibrable second electrode 18 may be attached to the resistance spot welding apparatus 15 at a nodal plane 36 of the vibratory energy. A process for employing the apparatus 10 is also presented.

A device of vibro-spot welding includes: a vibration cylinder housing having first and second chambers; an annular rod integrally connected with a first piston disposed in the first chamber and having one end penetrating a side of the vibration cylinder housing; a circular rod penetrating the annular rod integrally connected to a second piston disposed in the second chamber and having one end penetrating the side of the vibration cylinder housing; a leading-in housing wrapping an exterior surface of the vibration cylinder housing and receiving current; an electrode supporter threaded with one end of the leading-in housing; a heating electrode threaded with one end of the electrode supporter; a first vibration electrode threaded with the one end of the annular rod and penetrating the electrode supporter and the heating electrode; and a second vibration electrode threaded with the one end of the circular rod and penetrating the first vibration electrode.

A device of vibro-spot welding includes: a vibration cylinder housing having first and second chambers; an annular rod integrally connected with a first piston disposed in the first chamber and having one end penetrating a side of the vibration cylinder housing; a circular rod penetrating the annular rod integrally connected to a second piston disposed in the second chamber and having one end penetrating the side of the vibration cylinder housing; a leading-in housing wrapping an exterior surface of the vibration cylinder housing and receiving current; an electrode supporter threaded with one end of the leading-in housing; a heating electrode threaded with one end of the electrode supporter; a first vibration electrode threaded with the one end of the annular rod and penetrating the electrode supporter and the heating electrode; and a second vibration electrode threaded with the one end of the circular rod and penetrating the first vibration electrode.

A vibration spot welding device according to an exemplary embodiment of the present invention may include a first welding tip that is disposed to contact one side surface of metal plates that are overlapped, and a second welding tip that is disposed to contact the other side surface of the metal plates corresponding to the first welding tip, wherein the second welding tip includes a first electrode portion that is disposed to contact the metal plate so as to transmit a current thereto, and a second electrode portion that is disposed to contact the metal plate so as to receive the current that is transferred from the first electrode portion through the metal plate.

A vibration spot welding device according to an exemplary embodiment of the present invention may include a first welding tip that is disposed to contact one side surface of metal plates that are overlapped, and a second welding tip that is disposed to contact the other side surface of the metal plates corresponding to the first welding tip, wherein the second welding tip includes a first electrode portion that is disposed to contact the metal plate so as to transmit a current thereto, and a second electrode portion that is disposed to contact the metal plate so as to receive the current that is transferred from the first electrode portion through the metal plate.