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US 8,127,584 B2Granted
Prestressed rolling mill housing assembly with improved operational features
AssigneeI2S, LLC
InventorRemn-Min Guo
Life of this patent
Estimating the term…
Abstract
The present invention provides a Cluster mill which utilizes a Cluster mill gauge control system, has a high mill stiffness, a large work roll gap for threading, a rapid work roll gap opening, accurate roll force computation, side to side tilting, and utilizes work rolls over a much wider diameter range.
Claims27
A cluster mill housing assembly for a rolling operation to reduce a gauge of a flat metal strip, the assembly comprising:
- a. a first housing, having a plurality of corners, wherein said first housing has a roll cavity configured to receive a first plurality of rolls,
- b. a second housing, wherein said second housing has a roll cavity configured to receive a second plurality of rolls,
- c. a plurality of vertical prestress rods, wherein at least one of said vertical prestress rods is located at each of the plurality of corners of said first housing and at each of the corresponding corner of said second housing, wherein said first housing moves vertically relative to said vertical prestress rods, wherein each of said plurality of vertical prestress rods is rigidly attached to said second housing,
- d. a hydraulic tensioning and positioning control system that includes a first plurality of hydraulic cylinders, each including a piston, each said piston being connected to one of said plurality of vertical prestress rods, wherein said first plurality of hydraulic cylinders is connected to said first housing, wherein said first plurality of hydraulic cylinders is used to create a respective predetermined tensile load in each one of said plurality of vertical prestress rods, wherein said predetermined tensile loads are at least large enough to create a compression stress in both said first housing and said second housing during said rolling operation, wherein said hydraulic tensioning and positioning control system is operable to increase a vertical separation between said first housing and said second housing in the event of a break in said flat metal strip during said rolling operation, wherein said hydraulic tensioning and positioning control system further includes a second plurality of hydraulic cylinders operatively connected to the cluster mill housing assembly, wherein each one of said second plurality of hydraulic cylinders includes a piston, wherein said hydraulic tensioning and positioning control system includes a hydraulic position control system operatively coupled to said second plurality of hydraulic cylinders and configured to vertically position and maintain said first housing relative to said second housing during said rolling operation to set a predetermined gap between said first housing and said second housing, and
- e. a distance sensor system operatively coupled to said cluster mill housing assembly, wherein said distance sensor system measures a distance between said first housing and said second housing at each one of two selected points.
2 more elements
A method of operating a cluster mill, the cluster mill including:
- a cluster mill housing assembly that includes
- a) a first housing, having a plurality of corners, wherein said first housing has a roll cavity housing a first plurality of rolls including a first work roll,
- b) a second housing, wherein said second housing has a roll cavity having a second plurality of rolls including a second work roll,
- c) a plurality of vertical prestress rods, wherein at least one of said vertical prestress rods is located at each of a plurality of corners of said first housing and at each corresponding corner of said second housing, wherein each of said plurality of vertical prestress rods is rigidly attached to said second housing,
- d) a hydraulic tensioning and positioning control system that includes a first plurality of hydraulic cylinders, each including a piston, each said piston being connected to one of said plurality of vertical prestress rods, and a second plurality of hydraulic cylinders, each including a piston, wherein said first plurality of hydraulic cylinders is connected to said first housing, the second plurality of hydraulic cylinders is operatively connected to said cluster mill, a first hydraulic control system with sufficient control response to maintain said predetermined gap,
- e) the said pistons in the first plurality of hydraulic cylinders capable of moving the first housing vertically, the second said plurality of hydraulic cylinders capable of setting a predetermined gap between the first and second housing, the said hydraulic sensors having sufficient control response to allow said hydraulic tensioning and positioning control system to operate said second set of hydraulic cylinders to maintain said predetermined gap,
- f) a distance sensor, operatively connected to said cluster mill, said sensor measures a distance between said first housing and said second housing,
- g) at least one support roll eccentric bearing on each side of said flat metal strip, wherein the gauge of said flat metal strip during said rolling operation is substantially controlled by a rotation of at least said one support roll eccentric bearing,
- the method comprising:
- moving said first housing vertically relative to said vertical prestress rods;
- using the hydraulic tensioning and positioning control system, hydraulically creating and controlling a respective predetermined tensile load in each one of said plurality of vertical prestress rods;
- using the hydraulic tensioning and positioning control system, hydraulically creating and controlling a compression stress in both said first housing and said second housing during said rolling operation;
- rolling the flat metal strip between the first and second work rolls;
- maintaining the predetermined gap during rolling based on a signal output from at least one distance sensor;
- using at least one eccentric bearing on each side of the strip, adjusting for and maintaining the desired output gauge;
- and
- using the hydraulic tensioning and positioning control system, increasing a vertical separation between said first housing and said second housing in the event of a break in said flat metal strip during said rolling of the flat metal strip.
14 more elements
A method of operating a cluster mill, the cluster mill including:
- a cluster mill housing assembly that includes
- a) a first housing, having a plurality of corners, wherein said first housing has a roll cavity housing a first plurality of rolls including a first work roll,
- b) a second housing, wherein said second housing has a roll cavity having a second plurality of rolls including a second work roll,
- c) a plurality of vertical prestress rods, wherein at least one of said vertical prestress rods is located at each of a plurality of corners of said first housing and at each corresponding corner of said second housing, wherein each of said plurality of vertical prestress rods is rigidly attached to said second housing,
- d) a hydraulic tensioning and positioning control system that includes a first plurality of hydraulic cylinders, each including a piston, each said piston being connected to one of said plurality of vertical prestress rods, and a second plurality of hydraulic cylinders, each including a piston, wherein said first plurality of hydraulic cylinders is connected to said first housing, said second plurality of hydraulic cylinders is operatively connected to said cluster mill, a first hydraulic control system with sufficient control response to maintain said predetermined gap,
- e) the said pistons in said first plurality of hydraulic cylinders capable of moving the first housing vertically, said second plurality of hydraulic cylinders capable of setting a predetermined gap between the first and second housing, the said hydraulic sensors having sufficient control response to allow said hydraulic tensioning and positioning control system to operate said second plurality of hydraulic cylinders to maintain said predetermined gap,
- f) a distance sensor, operatively connected to said cluster mill, said sensor measures the distance between said first housing and said second housing, said plurality of prestress rods each having a predetermined modulus,
- the method comprising:
- determining a rolling force deflection curve for setting up a cluster mill prior to rolling operations, wherein the determining of the rolling force deflection curve includes:
- retracting said second plurality of hydraulic cylinders;
- utilizing the hydraulic tensioning and positioning control system, prestress the first and second housing together based on a preselected pressure value in said first plurality of hydraulic cylinders;
- separating the first and second housing said second plurality of hydraulic cylinders;
- using a distance sensor, measuring the separation distance between the housings;
- computing, by combining said separation distances and said preselected prestress pressure, a mill modulus for the housings;
- computing, by combining said mill modulus and the known modulus from said plurality of prestress rods, an overall prestressed assembly modulus;
- computing, by utilizing said overall prestressed assembly modulus, a force-deflection curve;
- and
- outputting said force-deflection curve in a form suitable for an operator to utilize during later rolling operations.
15 more elements
Dependencies are inferred from the claim text.