METHOD OF REGULATION IN WINDING

Abstract: The invention concerns a method of regulation in winding, wherein a number of separate rolls (13a, 13b) are formed around separate roll cores placed one after the other side by side while supported by support members (11, 12) and while loaded by linear loads produced by the truncated rolls (14a, 14b) in a set of truncated press rolls (14). In the method of regulation, the distance at each particular time between at least one truncated roll (14a, 14b) in the set of truncated press rolls (14) and the beam (16) that loads the set of truncated press rolls (14) is measured. The measurement signal (S) is passed to a regulator (23), which gives a regulation signal (d) to the valves that control the actuators (17) of the beam (16) so as to adjust the distance between the beam (16) and the set of truncated press rolls (14) to the desired measure.

Description: Method of regulation in winding The invention concerns a method of regulation in winding, wherein a number of separate rolls are formed around separate roll cores placed one after the other side by side while supported by support members and while loaded by linear loads produced by the truncated rolls in a set of truncated press rolls. Owing to variations in the cross-direction profiles of the web to be wound, such as thickness, moisture, and roughness, the diameters of the adjacent rolls do not become precisely equally large in spite of the fact that, in principle, exactly equally long component webs are wound onto said rolls. Owing to the different diameters of the rolls, the roll cores placed in their centres are displaced in relation to one another during the progress of the winding so that their centres of rotation are separated and, at the same time, minor variation also occurs in the angular speeds of the rolls. Since the roll centres are, however, during the entire winding, in contact with one another, diverting forces arise between the winding cores and the rolls tend to "jump" , whereby the rolls that are being formed can be damaged. Owing to this detrimental vibration, in drum winding, it is usually necessary to run more slowly, i.e. to be content with a lower winding speed, which reduces the capacity of the machine and is, thus, uneconomical. In the prior-art solutions, the regulation of the position of the set of truncated press rolls takes place as follows. From the spool locks, the diameters of the rolls to be wound are measured, and the measurement signals are passed to a computer device. Based on the measurement signals, the computer device computes a guide value for the circuit of regulation of the beam that supports the truncated rolls. Further, the position of the beam is measured, and the measurement signal is passed to the regulator. The regulator passes a regulation signal to hydraulic valves, which control the hydraulic actuators of the beam. Drawbacks of this prior- art system of regulation are complicated computing, high requirement of precision, and requirement of a larger stroke length of the cylinders in the truncated press rolls. The object of the present invention is to provide an improvement over the prior-art methods for regulation of the position of a set of truncated press rolls. The method of regulation in accordance with the present invention is characterized in that, in the method of regulation, the distance at each particular time between at least one truncated roll in the set of truncated press rolls and the beam that loads the set of truncated press rolls is measured, that the measurement signal is passed to a regulator, which gives a regulation signal to the valves that control the actuators of the beam so as to adjust the distance between the beam and the set of truncated press rolls to the desired measure. In the method of regulation in accordance with the invention, the distance at each particular time between at least one truncated roll in the set of truncated press rolls and the beam is measured. The measurement signal is passed to a regulator. Further, a set value or a guide value is passed to the regulator. The regulator gives a regula- tion signal to the valves that control the cylinders in the beam, in which connection the cylinders adjust the distance between the beam and the truncated roll to the desired level. The invention will be described in detail with reference to some preferred embodi- ments of the invention illustrated in the accompanying drawings, the invention being, however, not supposed to be confined to said embodiments alone. Figure 1 is a schematic side view of a prior-art method of regulation. Figure 2 is a schematic side view of a preferred embodiment of the method of regulation in accordance with the invention. Figure 3 shows the embodiment as shown in Fig. 2 viewed from ahead. The prior-art method of regulation illustrated in Fig. 1 has been applied to drum winding. In Fig. 1 , the drum winder is denoted generally with the reference numeral 10. The drum winder 10 comprises carrier drums 11 and 12. The rolls 13a, 13b, etc. to be wound are denoted generally with the reference numeral 13. The set of truncated press rolls is denoted generally with the reference numeral 14. The set of truncated press rolls 14 is attached to a fastening bracket 15. The cylinders 19 which regulate the loading of the set of truncated press rolls 14 are attached, from one end, to the fastening brackets 15 and from the other end to the fastening bracket 18. The cylinders that displace the beam 16 that loads the set of truncated press rolls is denoted with the reference numeral 17. The procedure in the regulation of the position of the press roll in the set of trun- cated press rolls 14 as shown in Fig. 1 is as follows. The diameters of the rolls 13 are measured from the spool lock 20, and the measurement signal a is passed to the computer device 22. The position of the beam 16 is measured by means of the position measurement device 21, and the measurement signal b is passed to the regulator 23. The computer device 22 computes a guide value c from the measure - ment signal a, which value c is passed to the regulator 23. The regulator 23 gives a regulation signal d to the hydraulic valves 24, which control the cylinders 17 of the beam 16. In the embodiment shown in Figs. 2 and 3, the distance at each particular time between at least one truncated roll 14a, 14b in the set of truncated press rolls 14 and the beam 16 is measured. The measurement signal S is passed to the regulator 23. The set value or the guide value A is also passed to the regulator 23. The regulator 23 gives the regulation signal d to the hydraulic valves 24, which control the cylinders 17 in the beam 16. In Fig. 2, the measurement detector is denoted with the reference numeral 25. In principle, one detector 25 is needed only, but, as a rule, it is recommended to use two or three detectors 25. There is one cylinder 19 for each truncated roll 14a, 14b in the set of truncated press rolls 14, in other words each truncated roll 14a, 14b has a cylinder 19 of its own. The cylinders 19 are attached from one end to the fastening brackets 15a, 15b and from the other end to the fastening bracket 18. Above, just a preferred embodiment of the invention has been described, and it is obvious to a person skilled in the art that numerous modifications can be made to said embodiment within the scope of the inventive idea defined in the accompanying patent claims.

Claims: Claims 1. A method of regulation in winding, wherein a number of separate rolls (13a, 13b) are formed around separate roll cores placed one after the other side by side while supported by support members (11,12) and while loaded by linear loads produced by the truncated rolls (14a, 14b) in a set of truncated press rolls (14), characterized in that, in the method of regulation, the distance at each particular time between at least one truncated roll (14a, 14b) in the set of truncated press rolls (14) and the beam (16) that loads the set of truncated press rolls (14) is measured, that the measurement signal (S) is passed to a regulator (23), which gives a regulation signal (d) to the valves that control the actuators (17) of the beam (16) so as to adjust the distance between the beam (16) and the set of truncated press rolls (14) to the desired measure. 2. A method of regulation as claimed in claim 1 , characterized in that a measure¬ ment signal (S) is received from at least one detector (25).

Inventors: LESKINEN ARTO, VAINIO PERTTI, LESKINEN, ARTO, VAINIO, PERTTI
Applicants: VALMET CORP, VALMET CORPORATION
Application year: 1997
Main classification: B65H18
IPC codes: B65H18