A robot system includes: an articulated type robot which retains a processing tool at an arm tip end portion and which includes a plurality of drive units that drive a plurality of drive axes; and a robot controller which controls the drive units so as to control a relative position of the processing target and the processing tool and the robot controller includes: a torque information detection unit which detects torque information on the torques of the drive units; a contact position estimation unit which estimates, based on the change of tendency of a variation in the detected torque information of at least one of the drive units, a contact position in which the processing target and the processing tool make contact with each other; and a position compensation unit which compensates the target position of the robot based on the estimated contact position.

This spot welding method is a method for joining workpieces being a layered body of three or more metal sheets by supplying welding current. The welding current has a pulse-like waveform wherein a peak state in which the current reaches or is maintained to be within a set peak current range and a non-peak state in which the current is lowered from the peak current range to a set bottom current, and is then increased toward the peak current range again are alternately achieved. In the non-peak state, in the case where an effective value Irms of the welding current is lowered, and reaches a predetermined effective value target range, a current control process for increasing the welding current toward the peak current range is started.

A bonding system is used for bonding a cover sheet to a core to form or repair a dual wall structure. The bonding system includes a plurality of bonding probes and controller circuitry. The bonding probes include a three dimensional (3D) contoured tip configured to align with a predetermined area of a 3D contoured cover sheet of a dual wall structure. The controller circuitry comprises processor circuitry and sensor circuitry. The sensor circuitry provides a location of an area of the 3D contoured cover sheet for bonding. The processor circuitry identifies a bonding probe having a contacting area that aligns with the 3D contour of the cover sheet in the location provided by the sensor circuitry.

A method of controlling highly regulated power and frequency from a high frequency power supply system to provide a highly regulated power and frequency to a workpiece load where the highly regulated power and frequency can be independent of the workpiece load characteristics by inverter switching control and an inverter output impedance adjusting and frequency control network that can include precision variable reactor pairs with a geometrically-shaped moveable insert core section and a stationary split-bus section with a complementary geometrically-shaped split bus section and a split electric terminal bus section where the insert core section can be moved relative to the stationary split-bus section to vary the inductance of the variable reactors.

The present invention provides a spot welding method for a member to be welded constituted of a plurality of steel sheets that are overlapped with each other at at least a welding zone, in which at least an overlapped face of at least one of the plurality of steel sheets at the welding zone is coated with zinc plating, a total sheet thickness t (mm) of the plurality of steel sheets is 1.35 mm or more, a squeeze time St (seconds) from the time when welding electrodes are brought into contact with the member to be welded to the time when electric current flow for welding starts satisfies “0.020≤St”, and a hold time Ht( seconds) after welding from the time when electric current flow for welding between the welding electrodes ends to the time when the welding electrodes and the member to be welded are brought out of contact satisfies “0.015t.sup.2+0.020≤Ht”.

The present invention provides a spot welding method for a member to be welded constituted of a plurality of steel sheets that are overlapped with each other at at least a welding zone, in which at least an overlapped face of at least one of the plurality of steel sheets at the welding zone is coated with zinc plating, a total sheet thickness t (mm) of the plurality of steel sheets is 1.35 mm or more, a squeeze time St (seconds) from the time when welding electrodes are brought into contact with the member to be welded to the time when electric current flow for welding starts satisfies “0.020≤St”, and a hold time Ht( seconds) after welding from the time when electric current flow for welding between the welding electrodes ends to the time when the welding electrodes and the member to be welded are brought out of contact satisfies “0.015t.sup.2+0.020≤Ht”.

A spot welded joint in which a high CTS is obtained even if including one or more high strength steel sheets and a method of welding of the same, that is, a spot welded joint 1 including a plurality of steel sheets, wherein one or more steel sheets is a tensile strength 750 to 2500 MPa high strength steel sheet and, at a cross-section in the sheet thickness direction of the steel sheets, when defining superposed surfaces of a high strength steel sheet S1 arranged at an outermost side and another steel sheet 1B as the “plane A” and defining a plane passing through a point of one-half of a distance between a nugget end position E of a high strength steel sheet S1 side on the line L1 in the sheet thickness direction and a crossing point O of the plane A and the line L1 and parallel to the plane A as the “plane B”, at a square area SA of sides of 30 μm centered about a crossing point X of a line L2, which is separated by 250 μm to the heat affected zone side from a tangent at any position on a nugget end line NEL sandwiched between the plane A and plane B and parallel to that tangent, and a line L3 vertical to L2 included in a heat affected zone 4 having a high strength steel sheet S1 as a base material, an average value of widths of the blocks formed from lath martensite is 0.5 to 7.0 μm.

A spot welded joint in which a high CTS is obtained even if including one or more high strength steel sheets and a method of welding of the same, that is, a spot welded joint 1 including a plurality of steel sheets, wherein one or more steel sheets is a tensile strength 750 to 2500 MPa high strength steel sheet and, at a cross-section in the sheet thickness direction of the steel sheets, when defining superposed surfaces of a high strength steel sheet S1 arranged at an outermost side and another steel sheet 1B as the “plane A” and defining a plane passing through a point of one-half of a distance between a nugget end position E of a high strength steel sheet S1 side on the line L1 in the sheet thickness direction and a crossing point O of the plane A and the line L1 and parallel to the plane A as the “plane B”, at a square area SA of sides of 30 μm centered about a crossing point X of a line L2, which is separated by 250 μm to the heat affected zone side from a tangent at any position on a nugget end line NEL sandwiched between the plane A and plane B and parallel to that tangent, and a line L3 vertical to L2 included in a heat affected zone 4 having a high strength steel sheet S1 as a base material, an average value of widths of the blocks formed from lath martensite is 0.5 to 7.0 μm.

A capacitive discharge welding system includes at least one capacitive discharge-based power supply that is adapted to provide alternate polarity pulses from a first weld to a subsequent weld, and to be compatible with iron-core transformers used for alternating current resistance welding; at least one iron core transformer adapted to receive electrical discharges from the capacitive discharge-based power supply; a polarity switching network that includes at least two sets of silicon controlled rectifiers that are arranged in pairs for facilitating current flow in alternate directions; a pair of engagable, properly biased shunt diodes that are operative to shunt reflected current for protecting the silicon controlled rectifiers when the system is in use; and a control network configured for simultaneous engagement of the properly biased shunt diodes and firing the silicon controlled rectifiers for current flow; and tracking polarity for assuring that subsequent pulses use opposite direction current flow for preventing saturation of the iron core transformer.

A capacitive discharge welding system includes at least one capacitive discharge-based power supply that is adapted to provide alternate polarity pulses from a first weld to a subsequent weld, and to be compatible with iron-core transformers used for alternating current resistance welding; at least one iron core transformer adapted to receive electrical discharges from the capacitive discharge-based power supply; a polarity switching network that includes at least two sets of silicon controlled rectifiers that are arranged in pairs for facilitating current flow in alternate directions; a pair of engagable, properly biased shunt diodes that are operative to shunt reflected current for protecting the silicon controlled rectifiers when the system is in use; and a control network configured for simultaneous engagement of the properly biased shunt diodes and firing the silicon controlled rectifiers for current flow; and tracking polarity for assuring that subsequent pulses use opposite direction current flow for preventing saturation of the iron core transformer.