Machine for continuous flash butt welding

A machine for continuous flash butt welding of parts, comprising:

• a welding transformer with a primary winding and a secondary winding;
• a frame;
• a movable clamping jaw and a stationary clamping jaw mounted on said frame for clamping workpieces mounted thereon;
• a follow-up slide valve including a valve body and a rod;
• hydraulic actuator means for displacing said movable clamping jaw and governed by said follow-up slide valve;
• an automatic flashing-off speed control device;
• a computer having an output, and including an automatic beginning-of-upset control device and an automatic upset value control device having an input, said computer, said automatic beginning-of-upset control device and said automatic upset value control device being incorporated in one unit;
• a welding current meter forming one element of a welding circuit, and having an input connected to said primary winding of the welding transformer, and having an output;
• first sensor means connected to the output of said welding current meter for detecting a short-circuit duration in the welding circuit;
• control means having an output for controlling an upset value deviation, and provided with second sensor means for detecting slippage of said workpieces mounted on and welded in said clamping jaws;
• third sensor means mounted on said follow-up slide valve for indicating misalignment of said rod of said follow-up slide valve relative to said valve body, and having an input and an output, said output of the third sensor means being connected to the input of said control means;
• a welding control enabling signal generator having an input and outputs, said input of the welding control enabling signal generator being connected to the output of said computer, said outputs of the welding control enabling signal generator being connected to said first sensor means for detecting short-circuit duration in the welding circuit and to said control means;
• and
• actuators of said automatic flashing-off speed, beginning-of-upset and upset value control devices for controlling the flashing-off speed, beginning of upset operation, and upset value, respectively, being combined in a further single unit.