Method for automatically controlling spinning rolls

Abstract

A method for the automatic control of the setting of spinning rolls in relation to a cylindrical, tubular workpiece in an opposed roll spinning lathe with four pairs of rolls. Each of the four pairs of rolls consists of one inner roll and one outer roll each, of which is arranged on a holder on a carrier so as to be radially adjustable in relation to the workpiece and so that the pairs of rolls are arranged at equal circumferential spacing about the workpiece so that the roll pair acting as the first rolling stage is placed diametrically opposite the second roll pair operating as the second rolling stage, the roll pair operating as the third rolling stage is offset by 90.degree. in relation to the first roll pair and is diametrically opposite the roll pair operating as the fourth rolling stage so that during the spinning rolling process the pairs of rolls and the workpiece perform a translatory and a rotary motion and furthermore the radial forces acting on the rolls are continuously measured. During the coming into working engagement with the workpiece and the stationary rolling process the radial forces occurring at like rolls whether (inner or outer) of the respectively oppositely placed roll pairs are compared with each other and if a permissible differential force is exceeded, the roll of the respective preceding roll stage is adjusted radially to compensate the lack of force equilibrium and simultaneously however the compared or reference roll is kept in a radial position corresponding to its initial basic value.