The present invention provides a weld control monitoring system (10) which determines the quality of the welds in real time, and provides responsive useful outputs indicating the quality of the weld The system (10) permits the user to input weld data as well as quality specifications which the part must meet in order to continue the production run A monitoring system can be used with or without programmable logic controllers (16) and includes special program for estimating the tip wear of the welding electrodes (34) The present invention also includes a weld gun control Additional travel for the weld gun electrode (34) is provided by cylinder (40) adjacent rail structures (50) which permit displaceable movement of the electrode mounted to linear displacement welding cylinder (30) An LVDT sensor (35) coupled to the piston rod (32) of the weld cylinder provides linearly variable displacement transducer signals for use in monitoring portion (14) of the apparatus The monitoring apparatus (14) also provides statistics of individual and groups of parts produced with the welding apparatus

Automatic welder control system

Automated handling systems and methods for using the handling systems for handling a work piece in a machining process, for example, an electrical discharge machining (EDM) process, are provided. The handling systems include a robotic manipulator adapted to grasp a work piece and locate the work piece in a machining operation, such as, an EDM machining operation. The robotic manipulator includes tooling having gripping devices adapted to grasp and position the work piece so that the work piece can be transferred and positioned, for example, precisely positioned, whereby accurate machining of the work piece can be practiced with little or no custom tooling. Methods for handling a work piece are also disclosed.

Methods and systems for handling a work piece for a machining process

An electrode displacement monitoring and control system for predicting and adaptively controlling resistance weld quality. The distance (34) between the movable electrode (16) and a fixed point such as on a workpiece (12) surface is monitored during a resistance weld cycle. The displacement information is processed and applied as a control signal for dynamically and adaptively varying various weld parameters including current application in order to control weld quality. A reversal in the direction of electrode displacement is identified and used in the adaptive control strategy.

Electrode displacement monitoring and control

A system and method is disclosed for monitoring and controlling a resistance projection welder for welding a projection weld nut to a workpiece. A displacement sensor measures the displacement of a welding electrode of a weld gun in real time during the welding procedure. A computer is coupled to the displacement sensor and determines whether the projection weld nut is correctly loaded between the workpiece and the welding electrode. The computer instructs a programmable logic controller (PLC) to trigger a weld controller to apply power to the welding electrode if the projection weld nut is correctly loaded onto the workpiece. The computer instructs the PLC to inhibit power if it determines the projection weld nut to be inverted, missing, or misaligned in order to allow for the removal and replacement of the projection weld nut. The computer further instructs the PLC to control and terminate the power to the welding electrode in real time in order to form a projection weld between the projection weld nut and the workpiece that is substantially similar to a predetermined projection weld. The computer processes the displacement data and provides a fault signal when the projection weld is unacceptable. A marker marks the unacceptable workpieces in response to the fault signal.

Resistance projection welding system and method for welding a fastener element to a workpiece

An apparatus and method for resistance welding tubular parts. The apparatus includes a weld gun having electrodes with arcuate contact faces engaging the parts. The electrodes are displaceable relative to each other. The contact faces are designed to distribute the force applied to the parts to prevent deformation and to hold the parts together steadily in order to minimize the amount of undesired electrode displacement caused by these effects. A test computer monitors the amount of electrode displacement occurring as a result of penetration of the parts into each other during welding. When the displacement between the electrodes falls within a predetermined displacement range, which is indicative of a proper weld between the parts, the computer cooperates with a weld controller to terminate the welding power, thereby inhibiting any substantial further penetration of the parts. The apparatus and method is suitable for tube-to-tube and wire-to-tube applications commonly performed in the manufacture of automobile seats.

Apparatus and method for resistance welding tubular parts

An assembly is provided for mounting on an end of a robot arm actuator as an integral spot resistance welding gun and transformer unit. A gun slide support bracket is connected to the transformer and serves to provide a mount for a sliding gun cylinder having a piston connected to one of the jaw electrodes. The lower jaw is removably connected to the cylinder. Roller shunts are used to provide electrical connection between secondary terminals on the transformer and the two electrodes. A proximity switch assembly is advantageously utilized to provide signals to the robot controller indicating a fully retracted position of the jaws.

Dimitrios G. Cecil

Papers

Resistance spot welding gun and transformer assembly