US 6,875,948 B2Granted

Method and device for controlling the welding by flash welding of two metallic parts

AssigneeVai Clecim

InventorsPascal Gobez, Afchine Nasserian, Marc Valence

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Abstract

The invention concerns a method for controlling the butt welding, by flash welding, of two metallic parts (A, A′) in a welding machine of the type comprising two pairs of clamping dies (2, 2′) mounted respectively on a fixed frame (1) and on a mobile frame (1′) for contacting rear (3) and front (3′) ends of both parts (A, A′) and the flow of an electric welding current. According to the invention, on the one hand a set of electric parameters including at least the voltage (Us) and the intensity (Is) of the welding current and on the other hand the relative position of the mobile frame (1′) with respect to the fixed frame (1) are measured at any moment and the travel of the mobile frame (1′) is regulated in position from at least one of the measured value of said electric parameters, in order to control the closing-in speed v(t) of the ends (3, 3′) of both parts (A, A′) taking in account the progress of the welding process, during at least a portion thereof.

Claims16

Dependent claims

Method for controlling the butt welding process, by flash welding, of two metallic parts arranged after one another along a longitudinal running axis, in a welding machine of the type comprising two pairs of clamping dies mounted respectively on a fixed frame and on a mobile frame moveable with respect to the fixed frame, electric welding means comprising an electric power supply source with two poles connected respectively to both pairs of clamping dies, means for controlling the clamping of both pairs of dies, respectively close to a rear end in the running direction, of a first part and close to a front end of a second part, and means for controlling the longitudinal travel of the mobile frame with respect to the fixed frame, for contacting said rear and front ends of both parts and the flow of an electric current with a welding voltage and intensity, a method wherein the travel of the mobile frame is controlled automatically, at least during the flash welding process,

wherein the value of a set of electric parameters including at least the voltage and the intensity of the welding current and, the relative position of the mobile frame with respect to the fixed frame are determined at any moment and the travel of the mobile frame, is controlled in position from at least one of the values thus determined, in order to control the relative position and the closing-in speed v(t) of the ends of both parts according to the progress of the welding process, during at least a portion thereof.

A device for controlling the flash butt welding of two metal parts arranged after one another along a longitudinal running axis, in a welding machine of the type comprising two pairs of clamping dies mounted respectively on a fixed frame and on a mobile frame moveable longitudinally with respect to the fixed frame, electric welding means comprising an electric power supply source with two poles connected respectively to both pairs of clamping dies, means for controlling the clamping of both pairs of dies, respectively close to a rear end, in the running direction, of a first part and close to a front end of a second part, and means for controlling the longitudinal travel of the mobile frame with respect to the fixed frame, for bringing closer and contacting said rear and front ends of both parts and the flow of an electric current between said ends, with a welding voltage and intensity, capable of heating and welding said ends in contact,

said controlling device comprising:
means (8) for continuous measurement of a set of electric welding parameters including at least the voltage and the intensity of the welding current flowing between both pairs of dies,
measuring means, at any moment, of the relative position of the mobile dies with respect to the fixed dies,
position regulation means for controlling in position the travel of the mobile frame from at least one of the measurements of the said electric welding parameters, with real-time control of the closing-in speed of the clamping dies of both parts.

1 more element

Dependencies are inferred from the claim text.