Bending of long material such as pipe or plate - esp. via machine contg. row of bending rolls for mfg. serpentine pipe coils

摘要

One end of the workpiece, e.g. a pipe, is fixed in a clamp, while the other end of the pipe is fixed in a second clamp which can move axially. One side of the pipe is then supported by >=2 rolls while >=1 bending roll is driven transversely to make a loop in the pipe. One pref. bending machine is fitted with a row of four support rolls, and three bending rolls which are moved synchronously and transversely to make a serpentine coil from the pipe. During the bending process, the spaces between the rolls are reduced in directions parallel with the longitudinal axis of the initial straight pipe. The pipe is pref. overbent, spring-back in the material producing the correct geometry after the clamps and rolls have been removed. An inexpensive and accurate bending machine is provided with low wear of the bending tools.