Method for adjusting the energy consumption of two tools during the machining of pipe section ends

A method for machining a longitudinal pipe section (1) having a first and a second end (3, 3′), comprising the steps of:

• utilizing a first and second rotating tool head (6, 7) to machine the first and the second end (3, 3′), wherein the first and second tool head rotate simultaneously and in opposite directions on a same axis of rotation R and each of the tool heads (6, 7) forms an outside chamfer (8, 8′), an inside chamfer (9, 9′) and a flat face (10, 10′) on each of the two pipe section ends (3, 3′);
• abrading a material continuously by the first and second rotating tool head (6, 7) during a machining period (t);
• dividing the machining period (t) into time increments (Δti);
• measuring a torque (M(ti,) M′(ti)) of the first and second rotating tool head (6, 7) for each time increment (Δti);
• determining an individual energy consumption (E(Δti), E′(Δti)) for each time increment (Δti), wherein said individual energy consumption corresponds to an individual quantity of material abraded during the time increment (Δti);
• and
• determining a total energy consumption (E(t), E′(t)) of both the first and of the second rotating tool head (6, 7) from the individual energy consumptions (E(Δti), E′(Δti)), wherein said total energy consumption corresponds to the total quantity of abraded material;
• adjusting the total energy consumptions (E(t),E′(t)) to a predefined ratio;
• wherein the abraded quantity of material of the first and second end (3, 3′) is determined continuously;
• and
• wherein the first and second rotating tool heads (6, 7) are controlled that when the total energy consumption E(t) of the first tool head (6) is greater than the total energy consumption E′ (t) of the second tool head (7), the rate of advance of the second tool head (7) is increased in comparison to the first tool head (6) and in that an angular velocity ω(ti), ω′ (ti) of the tool head (6, 7) is measured during each time increment Δti and an individual energy consumption (E(Δti),E′(Δti)) during the time increment (Δti) is determined from the angular velocity ω(ti), ω′ (ti) and the torque (M(ti), M′(ti)) and the duration of the time increment (Δti).