Controlling hydraulic actuating cylinders in roll stands

Abstract

The invention relates to a hydraulic feedback control loop (1) for controlling a hydraulic actuating cylinder (3), in particular an adjustment cylinder for a working roll in a roll stand. The actuating cylinder comprises a cylindrical housing (31) and a piston (32) slidably arranged therein. The piston divides the housing interior into a first hydraulic chamber (34) and a second hydraulic chamber (35). The feedback control loop (1) comprises: at least one first hydraulic valve (10) which is designed to apply a hydraulic fluid to the first hydraulic chamber (34), wherein the hydraulic pressure of the first hydraulic chamber (34) can be adjusted by actuating the first hydraulic valve (10); at least one second hydraulic valve (11) which is designed to apply a hydraulic fluid to the second hydraulic chamber (35), wherein the hydraulic pressure of the second hydraulic chamber (35) can be adjusted by actuating the second hydraulic valve (11); an adjusting device (12-20) which is provided and designed for actuating the two hydraulic valves (10, 11) in order to actuate, in a position control state, the second hydraulic valve (11) by means of a position control signal dependent on the working position of the piston (32) and to actuate, in said position control state, the first hydraulic valve (10) by means of an adapted position control signal, which is a signal generated on the basis of the position control signal.

Description

technical field [0001] The invention relates to a hydraulic control circuit and a method for controlling a hydraulic control cylinder, in particular a control cylinder for work rolls in a rolling stand, preferably a vertical rolling stand. Background technique [0002] It is known to adjust the roll gap between two work rolls by means of hydraulic adjusting cylinders. For this purpose, the end-side bearings of one or more work rolls are held displaceably by adjusting cylinders. Especially in the case of vertical rolling stands, the adjusting cylinders can have a relatively long stroke. In this case, the actuation of the adjusting cylinder can be realized by so-called "2-edge control" or "4-edge control". [0003] In 2-edge control, hydraulic fluid flows into and out of the piston-side cylinder chamber via one or more sequential valves, while the rod-side cylinder chamber is kept at a constant pressure. The continuous valve is used here as a regulating element for position...

AI Technical Summary

Problems solved by technology

As a result, changes in the behavior of the control loop, such as the influence of possible valve wear under load on the stability of the control loop, are not taken into account

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