摘要:
Control of third octave vibrations in a mill stand can be achieved using a high-speed piezoelectric assist coupled to a hydraulic gap cylinder to increase the damping of the roll stack. Vertical movements of the roll stack (e.g., the top work roll) can be determined through observation (e.g., measurement) of hydraulic fluid pressure of the hydraulic cylinder or entry tension of the metal strip. After determining vertical movements of the roll stack, a desired change in hydraulic pressure can be determined to overcome, reduce, or prevent third octave vibration. This desired change in hydraulic pressure can be effectuated at high speeds (e.g., at or above approximately 90 hertz) using the piezoelectric assist.
摘要:
The present application relates to a vibration damping system for a rolling mill comprising a rolling cage and a bending adjustment system (3,3′) of the rollers comprising hydraulic actuators acting on the rollers and hydraulic circuits (18, 19) for feeding, and hydraulic damping means (25, 31, 32) of a force connected to the hydraulic circuits (18, 19) for actuating a damping effect by means of the hydraulic actuators. The hydraulic damping means comprises a pair of hydraulic pumps (25B, 25C) or a pair of hydraulic cylinders with a dual chamber, connected in an opposite direction to each other to the hydraulic circuits (18, 19).
摘要:
An apparatus for cooling a hot rolled steel strip including a transfer means comprising transfer rolls to feed a steel strip which has been hot rolled by a finishing mill; a cooling means for cooling the steel strip; and accompanying rolls arranged with a clearance over the thickness of the steel strip at a position where the accompanying rolls face the transfer rolls through the steel strip to be transferred. The accompanying rolls rotate at nearly an equal peripheral speed as the transfer rolls or at a peripheral speed greater than the transfer speed of the steel strip.
摘要:
A method for cooling a hot rolled steel strip including transferring a hot rolled steel strip while ejecting cooling water from a cooling means at a specified ejecting condition; pinching a top end of the hot rolled steel strip by a pinching roll, at the inlet of the cooling means and/or just behind the cooling means and/or at a position on the way of the cooling means; and releasing the hot rolled steel strip sequentially from a pinch roll arranged at an upstream side, concurrently with the arrival of a top end of the steel strip to a tension adding means arranged at a downstream side.
摘要:
An apparatus for cooling a hot rolled steel strip including a transfer means comprising transfer rolls to feed a steel strip which has been hot rolled by a finishing mill; a cooling means for cooling the steel strip; and accompanying rolls arranged with a clearance over the thickness of the steel strip at a position where the accompanying rolls face the transfer rolls through the steel strip to be transferred. The accompanying rolls rotate at nearly an equal peripheral speed as the transfer rolls or at a peripheral speed greater than the transfer speed of the steel strip.
摘要:
A vibration damping roll is provided for rolling contact with a vibrating structure. The vibration damping roll incorporates a wave guide consisting of radially alternating rigid and flexible material having at least two rigid elements disposed adjacent to flexible material and may be provided in the form of a layered structure, a spiral structure, or a plurality of discrete rigid elements disposed in a matrix of flexible material.
摘要:
A lower surface cooling box 12 is arranged between transfer rolls 11 on a runout table 3 and an upper cooling box 14 moving freely is arranged at a position corresponding to the cooling box 12 to eject cooling water to the steel strip symmetrically in the vertical direction. The steel strip passes the center of converge of cooling water from upper and lower surfaces of the steel strip. A water breaking roll 16 is provided elevating freely at least at the outlet side rotating at the same peripheral speed as the transfer rolls and is rotated to lower concurrently with passing of the steel strip top at the cooling apparatus. The upper cooling box is also lowered concurrently to cool the steel strip.
摘要:
A system for controlling deflection of a dynamic surface includes at least one sensor in communication with the dynamic surface for detecting the presence of a deflecting force on the dynamic surface and generating a feedback signal proportional to the deflecting force. The system includes a controller in communication with the at least one sensor for receiving the feedback signal and generating an output signal in response to the feedback signal. At least one piezoelectric actuator is in communication with the dynamic surface and in communication with the controller for receiving the output signal and applying a counter deflecting force on the dynamic surface for removing the deflection from the dynamic surface. In other preferred embodiments, the piezoelectric actuators maintain the dynamic surface in a preferred shape, such as a curved surface.
摘要:
A method of preventing roll chatter in a stand of a rolling mill during the process of directing a strip of material through the mill. The method comprises the step of introducing into the stand a low power vibration component that prevents the rolls in the stand from vertically oscillating in any generally large, uncontrollable manner.
摘要:
A lubricant is supplied from headers of lubricant supply units onto surfaces of back-up rolls at locations spaced from contact positions between a pair of work rolls and a pair of back-up rolls. The headers each include a lubricant spray nozzle for spraying the lubricant under a pressure not lower than 3 kg/cm.sup.2, a header cover for confining the lubricant sprayed from the lubricant spray nozzle, an oil return line for returning the surplus lubricant, and seal members made of flexible material such as rubber. The work rolls are provided with water wiping plates, and the back-up rolls are also provided with water wiping plates. In a work rolls crossing type mill thus arranged, water films of cooling water deposited on the roll surfaces are removed to prevent the cooling water from mixing into the lubricant. Even if the water films are not totally removed, it is possible to surely plate out the lubricant for reliably lubricating between the work rolls and the back-up rolls. Raw lubricant oil of the lubricant meets the following requirements; (a) the coefficient of friction between said work rolls and said back-up rolls is in the range of 0.04 to 0.1, (b) the viscosity is not larger than 80 Cst. at 40.degree. C., (c) mineral oil and synthetic ester not less than 5% are contained as base oil, (d) a fatty acid in the range of 0.03 to 0.5% is contained as an oiliness enhancer, (e) an extreme pressure additive not less than 0.1% is contained, and preferably, (f) a surface active agent not larger than 0.5% is contained as emulsifier.