Peculiarities of the process of pipe stock piercing at a piercing mill

Abstract

Dynamic of power line of pipe rolling aggregate (PRA) piercing mill accounting behavior peculiarities of spindle joint and working rollers setting mechanism. A differential equation of the piercing mill main drive line motion composed and its numeral solution presented. An adapted three-mass dynamic system model considered and the task solution obtained with application of the Solid Works IT Simulation X program product. Basic conditions of non-stable dynamic phenomena origination in the power line and in the piercing mill working rollers setting mechanism formulated. It was shown, that the system non-stable dynamic is one of main reasons of results discrepancy of the known theoretical, experimental studies and pipe thickness measurements at PRA 350 piercing mills. Main reasons of parametric oscillation origination in the drive of working stand of a piercing mill determined, as well as the one in the working rollers setting mechanism due to the phenomena of pipe wall difference origination. Areas of the system stable functioning depending on operation regimes and working rollers supply angle determined accounting the space position of the spindle facility elements Necessary and sufficient conditions of joint stable functioning of the piercing mill power line formulated. To stabilize the pipe stock piercing process a modernization scheme of the main drive spindle and of the PRA 350 piercing mill working rollers setting mechanism proposed.