Gm Global Technolgoy Operations, Inc.

Peter C Sun

Pei-chung Wang

Kenneth R Schmidt

Douglas Martin Linn

Charles Weldon Wampler, Ii

Robin Stevenson

Charles W Wampler, Ii

Ningjian Huang

Chih-chang Chen

Daniel C Hutchinson

A system and method for self-piercing riveting including an alignment mechanism comprising laser diodes and sensors for facilitating alignment of a rivet gun and a back-up located on opposite sides of sheet metal parts to be joined, and an oscillation piercing technique for reducing force loads on structures, particularly robotic structures, carrying the rivet gun and the back-up.

System for programmable self-piercing riveting

A resistance welding apparatus having a pair of programmable ball electrodes carried on universally movable positioners. The positioners are programmed to move the ball electrodes simultaneously along a seam line so that the ball electrodes clamp and support opposite sides of a pair of stacked workpieces and are electrically charged to form resistance seam welds along the seam lines to connect the workpieces.

Programmable resistance seam welding apparatus and method

A method of spot welding a sheet overlapped to a tube with a servomotor-driven electrode applying a clamping force to the sheet. Over a first clamping time interval, the clamping force is increased to a first force level, at which point a welding current is applied to weld the sheet and tube together for a welding time interval. The first force level is maintained for a second clamping time interval, after which the clamping force is reduced to a second force level over a third clamping time interval and is maintained for a fourth clamping time interval. The welding current is removed upon expiration of the welding time interval and the clamping force is simultaneously reduced over a fifth clamping time interval, after which the electrode is disengaged from the sheet. The reduction in clamping force during the welding cycle reduces cracking of the spot weld.

Sheet-to-tube resistance spot welding using servo gun

A joint assembly for joining first and second tubular members. The first member has flanges extending from walls of an end segment. The walls of the end segment define a receiving opening. The second member has walls and a protrusion having sides extending from the walls to an end of the protrusion. When the members are joined the protrusion is received in the opening of the end segment so that the sides of the protrusion are in facing engagement with the walls of the end segment and the flanges engage the walls of the second member. The members are secured together at some of the engaging surfaces. The protrusion reduces stress on the flanges and increases the mechanical strength of the assembly.

Tubular joint assembly

A weld gun having a linkage, which relates pivotal motion of a pair of laterally opposed facing electrodes of the weld gun in a predetermined manner. Based upon the predetermined motion of the electrodes a welding robot positions the electrodes of the weld gun on opposite sides of a workpiece to be welded so that the electrodes simultaneously engage the workpiece on opposite sides.

Weld gun equalizer

Method and apparatus for detecting unacceptable misalignment of welding electrodes. An electrode-alignment station is positioned adjacent a welding station. A robot controls the movement of the electrodes, and occasionally moves the electrodes out of the welding station and into an electrode-alignment station. At the electrode-alignment station, the electrodes are closed on a fixture that transfers electrode-misalignment into movement of a plate that triggers an alarm if the misalignment is greater than a prescribed amount.

Electrode alignment inspector and method

In attempting to reduce deformity when joining vehicle frame components, a riveting/brazing process has been proposed. This process includes joining tubular members, such as hydroformed parts, by cutting at least one flange into one end of a first body member, shaped in conformance with the surface of a second body member. Location holes are formed into each flange as well as into the surface of the second member in suitable alignment with each other. A brazing filler material is fixed into a side of the flange, usually within a pocket, intending to lie on the surface of the second member when the two structures are attached. The flange(s) are initially attached to the surface of the second member by means of a rivet to formed an actual vehicle body assembly. Heat is then applied to the assembly to form a brazed T-joint.

Joining of tubular parts in a T-joint by riveting/brazing

A method for repairing resistance spot welds formed between joined pieces of aluminum alloy sheet metal, such as vehicle body parts. The repair method includes resistance welding where an existing undersized spot weld is enlarged by applying electric current flow through the aluminum alloy sheets in the region around the existing defective weld. A pair of donut shaped electrodes may be used. Resistance to the current flow generates heat within the weld region. A new weld nugget is formed around the periphery of the existing weld and merges with it. The weld region is cooled and a repaired composite spot weld is formed.

Method for repairing resistance spot welds in aluminum sheet materials

A pogo welding apparatus especially for spot welding metal sheets at selected locations spaced away from their edges wherein the sheets are held in a temporary assembly with the selected locations engaged and separate programmable positioners move a primary (pogo) electrode and a backup electrode sequentially against opposite sides of the selected locations to spot weld the sheets at the selected locations in sequence. Various alternative programmable positioners, including robots of varying types, may be used to carry the electrodes. A multi head back-up electrode is adapted for efficient use of the apparatus and method in difficult to reach workpiece locations.

Programmable pogo welding apparatus and method

A pogo welding apparatus especially for spot welding metal sheets at selected locations spaced away from their edges wherein the sheets are held in a temporary assembly with the selected locations engaged and separate programmable positioners move a primary (pogo) electrode and a backup electrode sequentially against opposite sides of the selected locations to spot weld the sheets at the selected locations in sequence. Various alternative programmable positioners, including robots of varying types, may be used to carry the electrodes.

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Rochester Hills, MI, United States of America

Peter C Sun