Abstract: A single side heating apparatus equipped with a pair of electrodes for heating a workpiece is provided. The apparatus includes: a base portion; the pair of electrodes each having a contact portion configured to contact with the workpiece in one direction continuously or at a plurality of spaced-apart portions thereof; an electrode holder, to which the pair of electrodes are fixed; and a four-bar linkage provided between the base portion and the electrode holder and configured to rotate to tilt the electrode holder around an axis orthogonal to the one direction by a reaction force received by the electrodes from the workpiece. The four-bar linkage includes a first link located closer to the electrode holder, a second link located closer to the base portion, and third and fourth links. The first link is shorter than the second link, and the third link and the fourth link are equal in length.

Abstract: A single side heating apparatus, which can make contact portions of electrodes properly contact with a workpiece, is provided.

Abstract: A metal-resin joining device joins a thermoplastic resin plate (12) to a metal plate (13) by melting the resin plate (12) in contact with the metal plate (13) through heating an exposed face of the metal plate (13) by one-sided resistive heating. The metal-resin joining device has a center electrode (24a) that is brought in contact with the metal plate (13) and a peripheral electrode (24b) that is brought in contact with the metal plate (13) to annularly surround the center electrode (24a) and to which a current flows from the center electrode (24a) via the metal plate (13), wherein the peripheral electrode (24b) is made of a metal material having a higher electrical resistance than the center electrode (24a).

Abstract: A metal-resin joining device joins a thermoplastic resin plate (12) to a metal plate (13) by melting the resin plate (12) in contact with the metal plate (13) through heating an exposed face of the metal plate (13) by one-sided resistive heating. The metal-resin joining device has a center electrode (24a) that is brought in contact with the metal plate (13) and a peripheral electrode (24b) that is brought in contact with the metal plate (13) to annularly surround the center electrode (24a) and to which a current flows from the center electrode (24a) via the metal plate (13), wherein the peripheral electrode (24b) is made of a metal material having a higher electrical resistance than the center electrode (24a).

Abstract: An electrode structure is provided in which an upper pin having a magnet is built in a cavity inside an upper electrode so as to be vertically movable to allow its front end portion to protrude downward, and a lower pin is arranged so as to face the upper pin and built in a cavity inside a lower electrode so as to be vertically movable to allow its front end portion to protrude upward. In a state where the front end portion of the upper pin protrudes downward, the weld nut inserted onto it is attracted and held by the magnet. In a state where the upper pin is pushed upward by the lower pin, the weld nut comes off the upper pin and drops due to a less attracting force by the magnet, and then fitted onto the lower pin at a position higher than a workpiece.

Abstract: A nut feeding apparatus for feeding a weld nut to an upper electrode of a resistance welding machine, whose size and production cost are reduced, is disclosed. The apparatus comprises a piston rod, a tension rod, a tube, a link mechanism and a nut chuck. When the piston rod is in a most retracting state, an upper surface of the nut chuck becomes substantially flush with a lower portion of an opening of the tube. While the tension rod is at a stop in a most advancing state and when the piston rod further advances, the link mechanism rotates around a rotation axis at a tip of the tension rod, and thereby, the weld nut held by the nut chuck moves to a feeding position of the weld nut in the upper electrode.

Abstract: A nut feeding apparatus for feeding a weld nut to an upper electrode of a resistance welding machine, whose size and production cost are reduced, is disclosed. The apparatus comprises a piston rod, a tension rod, a tube, a link mechanism and a nut chuck. When the piston rod is in a most retracting state, an upper surface of the nut chuck becomes substantially flush with a lower portion of an opening of the tube. While the tension rod is at a stop in a most advancing state and when the piston rod further advances, the link mechanism rotates around a rotation axis at a tip of the tension rod, and thereby, the weld nut held by the nut chuck moves to a feeding position of the weld nut in the upper electrode.

Abstract: An electrode structure is provided in which an upper pin having a magnet is built in a cavity inside an upper electrode so as to be vertically movable to allow its front end portion to protrude downward, and a lower pin is arranged so as to face the upper pin and built in a cavity inside a lower electrode so as to be vertically movable to allow its front end portion to protrude upward. In a state where the front end portion of the upper pin protrudes downward, the weld nut inserted onto it is attracted and held by the magnet. In a state where the upper pin is pushed upward by the lower pin, the weld nut comes off the upper pin and drops due to a less attracting force by the magnet, and then fitted onto the lower pin at a position higher than a workpiece.