Newfrey Lcc

Emhart Inc.

Emhart Enterprises Corp.

Wolfgang Schmidt

Klaus Gisbert Schmitt

Heiko Scheffler

Arne Friedrich

Klaus-Gisbert Schmitt

Udo Schulz

Michael Krengel

Harald Knetsch

Wolfgang Obermann

Reinhold Broehl

Silvia Hofmann, Legal Representative

Haymo Gottwals

Klaus Gisbert Schmidt

Heiko Gerhard Scheffler

A stud welding apparatus comprising a power supply including power electronics operable for supplying a variable welding voltage together with one of a pilot current and a welding current that is much larger than the pilot current; and a current measuring circuit operable for measuring the electrical current to the weld head; and an input circuit electrically connected between the power electronics and the power supply output, the input circuit including a first inductance, a first resistance, and a switch operable to bridge the first inductance and the first resistance; and a welding circuit electrically connected between the power supply output and the weld stud, the welding circuit having a welding circuit resistance and a welding circuit inductance, and the welding circuit inductance is much smaller than the first inductance of the input circuit; and a voltage measuring device is operable for measuring a voltage across the welding circuit.

Apparatus for determination of electrical welding circuit variables

A method for determination of electrical variables of a welding circuit which is connected to an electrical power supply device and operable to provide either a welding current or a lesser pilot current, the method including the steps of (a) determining the resistance of the welding circuit and (b) determining the inductance of the welding circuit.

Method for determination of electrical welding circuit variables

A heating current used to inductively heat a metallic or magnetic work-piece is generated by an inverter supplied by a supply voltage. The inverter includes four switching elements arranged in an H-bridge circuit having two parallel longitudinal branches and a transverse branch. The switches are controlled so the heating current flows through the transverse branch. The diagonally opposed switching elements are switched from a conductive to a non-conductive state in a temporally staggered manner.

Method and device for producing an electric heating current, particularly for inductive heating of a workpiece

A process and a system are proposed for short-time arc-welding elements, such as for example metal studs, on to components, such as for example metal sheets, wherein an element in the context of a welding operation is initially raised in relation to the component, a welding arc is formed between the element and the component, and the element is lowered again, the lifting height of the element in relation to the component being detected at least within a time segment between raising and lowering of the element. The initiation of the lowering operation and/or the lowering operation itself is controlled as a factor of the detected lifting height such that a previously specified total welding time is achieved.

Process for short-time arc-welding and short-time arc-welding system

The invention relates to a rapid arc welding system () for welding elements () onto components (). The inventive system comprises a welding head (), a supply device () for supplying elements () to the component () and a control and power device (). Said control and power device comprises a safety circuit for controlling the safety functions of the welding system () which allows an operation that is especially safeguarded from unauthorized use of the system in which an operation disruption is partially cancelled. In this partial operation mode, individual components of the system () can be activated selectively, especially for the purpose of maintenance.

Short-time arc-welding system and process for controlling such a system

A process and a system are proposed for short-time arc welding elements, such as for example metal studs, on to components, such as for example metal sheets, wherein an element in the context of a welding operation is initially raised in relation to the component, a welding arc is formed between the element and the component, and the element is lowered again, the lifting height of the element in relation to the component being detected at least within a time segment between raising and lowering of the element. The initiation of the lowering operation and/or the lowering operation itself is controlled as a factor of the detected lifting height such that a previously specified total welding time is achieved.

Process for short-time arc welding and short-time arc welding system

A process and a system are proposed for short-time arc welding, in particular for stud welding, with the step of sampling a welding parameter, in particular the arc voltage (U), during at least one time segment (T) of the welding operation, in order to detect disturbances, wherein the measurement curve determined from the sampling operation is smoothed and subsequently wherein at least one tolerance curve is generated which lies at a previously adjustable distance from the smoothed measurement curve, and subsequently the unsmoothed measurement curve is compared with the tolerance curve in order to detect high-frequency disturbances.

The present invention relates to a lift-and-strike welding process. In a first step, e.g. an aluminum surfaces ( ) of a component is cleaned by striking an arc and then the element ( ) to be connected is welded on by means of at least one second voltage. Besides a lift-and-strike welding apparatus, a further lift-and-strike welding process is also provided, wherein an electric cleaning current flows between a surface ( ) of a component and an element to be welded thereon, in that the component rests on the surface ( ) and then the element ( ) is lifted off the surface ( ) up to an approximately, in terms of time, constant distance for removing a coating from the surface ( ) by means of an arc, then the current changes its polarity, wherein afterwards at least one welding current is produced and then the element ( ) is welded to the surface ( ).

Lift-and-strike welding process with cleaning stage

Process for welding a weld stud onto a workpiece by means of a drawn arc, in which the weld stud is placed onto the workpiece and, with performance of a welding stroke, is removed from the workpiece in a return stroke, igniting a pilot arc, and is advanced toward the workpiece again in a forward stroke during the combustion of a connected welding arc. The welding arc is divided by pulse-wise current reduction to a minimum value into a sequence of current pulses and the last of these current pulses is extended in time by at least about 1.5 times relative to the preceding current pulses. This extended current pulse lasts substantially to the end of the forward stroke.

Arc welding of a weld stud

Control circuit for arc welding components to workpieces, in which a component is placed on to a workpiece by a weld gun and after a welding stroke is lifted from the workpiece in a return stroke by igniting a pre-current arc and is brought up to the workpiece again in a forward stroke during the burning of an interconnected welding arc, in which a sequencing control determines the tripping moments of return stroke and forward stroke as well as of the welding arc and a monitoring voltage is bypassed from the pre-current arc ignited at the welding point, characterized in that the monitoring voltage (V) is converted into a correction voltage (line 27) by means of a set-point comparator (25) and is superposed on a control voltage (line 18) for principally controlling a high-frequency modulated switching mode power supply unit (15) and said switching mode power supply unit (15), in accordance with the thus corrected control voltage, adjusts its output current (lines 13,14) during the respective welding operation to the resistance value of the pre-current arc established by the monitoring voltage (V) representing the respective welding data.

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Reiskirchen, Germany

Wolfgang Schmidt