The study of dynamic processes in the hydraulic system of the roll clamp of a two-cone unwinder rolls pipe-welding unit 159-529

Abstract

The work is devoted to the study of dynamic loads arising in the hydraulic system of the clamping mechanism of a roll of a two-cone unwinder of rolls of tubes of a pipe-welding unit 159-529. The operating experience of the two-cone unwinder has shown that one of its drawbacks is the unsatisfactory operation of the roll clamp hydraulic system, in which increased dynamic loads are observed. In the hydraulic system of the roll clamping mechanism, the executive hydraulic cylinder is located at a large distance from the pressure source, therefore, it uses long hydraulic lines. In transient modes of operation of a machine with such a hydraulic system, wave processes arise in it (unsteady fluid motion), which affect the quality of its functioning.Based on the analysis of mathematical models used in the practice of dynamic calculations of real hydraulic systems, it is shown that it is advisable to use a system of partial differential equations converted by a finite-difference method into a system as a mathematical model that takes into account the design and operation of the hydraulic system of the roll clamp mechanism of a two-cone unwinder ordinary differential equations with boundary conditions. This makes it possible to create a dynamic model that allows with high reliability to analyze the behavior of the hydraulic system of the mechanism of the clamping roll of a two-cone unwinder. During the implementation of the proposed mathematical model in the Simulink MATLAB software environment, a study was made of the operating modes of the hydraulic system of the roll clamping mechanism. As a result of the study, it was shown that in the hydraulic system of the roll clamping mechanism of a two-cone unwinder, dynamic loads occur at the end of the return stroke, which significantly exceed the permissible values.In order to reduce dynamic loads, a valve operating procedure with a response time of 0.16 seconds is proposed. This allows you to significantly reduce dynamic loads in the hydraulic system of the roll clamping mechanism by reducing the speed of movement of the hydraulic cylinders at the end of the carriage return stroke.