Draught strength which is necessary in roll straightener for wire

摘要

The field of use for wire straightening extends from rolling instruments to drawing mills and machines for converting wire. Besides the straight wire, the concerns often produce wire which is characterized by a certain and desired residual bending. Independently of type and specific uses, all the straightening tools are characterized by the necessity of letting move the wire through rolls. For the process configuration, and in order to guarantee a balanced project of machine manufacture, it is indispensable to know with precision the strength which must be applied to the wire and is called "draught strength", in order to convey it along the straightener. As a matter of fact, this strength affects the achievable process speed and motive power which must be installed. Another respect which renders this knowledge advisable, if not necessary, is the opportunity of optimizing the energy consumption. ISO 14000 rule, for instance, considers it. On the basis of these knowledges, the operators mean to answer the following requirements: the calculation of draught strength must be feasible for every sort of straightener; the results which are attained concretely must underline variances in comparison with the calculated ones which do not exceed +/-10 percent; there must be the possibility of consider the initial and final bending zones; it must be possible to calculate the draught strength for wires of every section, not only circular one. The model which was elaborated by Witels-Albert for calculating the draught strength, and expects the observation of a wire stretch during its passing through the staggered rolls of a straightener, is satisfactory enough in this viewpoint.