Patent ID: 7651019
Filing Date: 2010-01-26
Classification: B23K

Abstract:
1. A friction welding process comprises the following steps: a) providing first and second work pieces to first and second holding members, respectively, to be welded together; b) imparting rotary motion to the first work piece relative to the second work piece thereby imparting kinetic energy to the first work piece relative to the second work piece; c) applying a predetermined force to move one or both of the first and second work pieces towards the other to create an upset length in the work pieces; d) measuring a rate of motion of the first work piece relative to the second work piece; e) calculating a predicted final upset length based on the rate of motion of the first work piece obtained from the step (d) and the applied force from the step (c); f) comparing the predicted final upset length with a desired final upset length; and g) controlling an energy adjustment arrangement to directly adjust the kinetic energy of the first work piece by actively adjusting at least the rate of motion of the first work piece based on the measured rate of motion and the predicted final upset length to achieve substantially the desired final upset length.