ES2946466T3 - Intelligent loop-free lamination in long product laminators - Google Patents

Abstract

A laminator is provided for producing lamination products. The rolling mill includes a rolling mill line that moves product from the rolling mill. A plurality of rolling stands are coupled to the rolling line which receives the rolling product and rolls the rolling product. A plurality of speed measuring devices positioned in close proximity to each rolling stand, each speed measuring device measuring the speed of the product from the mill as it passes the speed measuring devices. A control device receives information associated with the speed measuring devices and adjusts the mill product speed for any speed differential that may exist between any of the mill stands. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Intelligent loop-free lamination in long product laminators

The invention relates to the field of manufacturing long products and, in particular, to manufacturing long products using intelligent tensionless or loopless rolling or a method thereof according to the preamble of claims 1 and 9.

Tension between stands is inherent in all long product rolling mills. In theory, the speed of each mill is derived from the work being carried out, however, due to differences in material distribution, roll wear, and material control, the speed between two product mills lengths never match 100%. This mismatch is called tension or compression, since the material can be pushed or stretched depending on the speed error between the two mills.

In the front end of a rolling mill, tension control is managed by a Minimum Tension Control (MTC) system. The MTC calculates the speed and torque of each rolling mill, allowing the speed to be adjusted. This control arrangement is described in JPS59118212A.

In the last part of the rolling mill, loops are used, which are natural interruptions in the rolling process. A loop is formed to provide a float zone or buffer in the continuous process between two rolling mills. This loop can be pushed or pulled as the speed of the laminator changes. If the loop grows or decreases outside of a preset position, the laminators can adjust their speeds accordingly in an attempt to maintain balance.

The theory is that with the loop in the ideal or deadband position, a speed error between the mill supports is compensated and the process remains stable. However, a loop never removes all tension or compression in the mill, since by nature the actual velocity of the material is never known and the push or pull force is inherent in the material. Loops include mechanical and electrical/automated (EA) equipment that have added cost and add length to the total mill, further increasing the total cost of a rolling line.

According to an aspect of the invention as claimed in claim 1, a laminator for producing lamination products is provided. The laminator includes a lamination line that moves the lamination product. A plurality of rolling stands are coupled to the rolling line which receives the rolling product and rolls the rolling product. A plurality of speed measuring devices which are positioned in close proximity to each mill stand, each speed measuring device measuring the speed of the product from the rolling mill as it passes the speed measuring devices. A control device receives information associated with the speed measuring devices and adjusts the speed of the mill for any speed differential that may exist between any of the mill stands, where the speed differential is the difference between the actual speed of the mill and a speed calculated at a point on the mill line.

According to another aspect of the invention, as claimed in claim 9, there is provided a method of producing roll product in a rolling mill. The method includes providing a rolling line that moves the rolling product. Furthermore, the method includes providing a plurality of roll stands that are coupled to the roll line that receives the roll product and rolls the roll product. A plurality of speed measuring devices are placed in close proximity to each roll stand, each speed measuring device measuring the speed of the rolled product as it passes the speed measuring devices. In addition, the method includes adjusting the speed of the roll product for any speed differential that may exist between any of the roll stands using a control device that receives information associated with the speed measuring devices, where the speed differential speed is the difference between the actual speed of the rolled product with a calculated speed at a point on the rolling line.

These and other advantageous aspects of the claimed invention will now be described in more detail with reference to the accompanying drawings.

Figure 1 is a schematic diagram illustrating the loopless rolling mill arrangement used in accordance with the invention; and

Figure 2 is a schematic diagram illustrating another embodiment of the loopless rolling mill arrangement used in accordance with the invention.

The invention describes a systematic approach that eliminates the need for a mechanical loop in a rolling mill and its associated control. The loop is replaced by a simple laser velocimetry system and/or a camera arrangement in which a laser is placed between each of the mill supports. This can include multi-roll machines but with a single drive motor.

In the prior art, the tension and loop control systems operate from a theoretical speed calculated from a theoretical working diameter. This change in diameter depends on the process section being rolled. Also, as the material is rolled in the mill, its area is reduced and it passes through each subsequent roll stand at higher speeds. This complicates belt design and control, as each belt must have enough buffer "storage" to effectively support and control smaller products or sections.

For example, if a section in question is moving at 15 m/s and the rolling stands in question have the ability to adjust at 2.5 m/s. So, the loop storage required for a 3% velocity differential would be 0.18m of material, from the start position or pitch line to break even.

The invention eliminates the need for the aforementioned complications and limitations, since the actual velocity of the product between the supports of the laminator is measured with non-contact velocimetry. In the early part of the rolling mill line, speed measurements can be used, since the rolling mill stands are located close to each other and the metallurgical process in the rolling mill does not require water cooling and/or equalization.

Figure 1 shows an illustrative example of the loopless rolling mill arrangement 2 used in accordance with the invention. Shuttleless Laminator 2 includes laminating line 4, rolling stands STD13 and STD14, cameras C12o, C13o and C14o, and output lasers L12o, L13o and L140. The rolled product is moved through various points in the rolling mill 2 using a rolling line 4 which passes through a number of rolling stands. Each STD13, STD14 mount includes a C12o, C13o, C14o camera and an L12o, L13o, L14o output laser.

Each C12o, C13o, C14o camera is used as a visual tool to assess the quality of the mill's product, such as the height of a section of material for precise control. Each laser L12o, L13o, L14o measures the actual speed of the product of the rolling line 4 and compares it with the speed calculated at this point and makes the necessary speed adjustments on the rolling stand in question and on subsequent rolling stands if necessary to balance the lamination process. The laminators are connected to a control system that allows the speed to be adjusted on each laminator. Both the laser and the camera can share a common stand or box.

In most rolling mills, individual holders are controlled from a master speed reference. This speed reference takes into account the calculated area reduction achieved on each roll stand, the roll diameter of each roll stand, and the associated gear ratio.

The error can manifest itself due to slightly incorrect roll profiles or diameters, poor section control in the mill, or slight differences in theoretical and actual gear ratios in the mill stands. In the slowest part of the mill, an MTC (Minimum Tension Control) system is used, which takes advantage of an iterative self-learning system to adapt the speeds of the rolling stands. Higher up the mill, this iterative approach is not possible as the speed error grows and the risk of mill stonewalling increases.

The means of controlling this speed error in most prior art rolling mills is the loop. The loop is mechanical equipment controlled by a ring. The loop allows for a mismatch in equipment speed giving the mill product a buffer space to grow a loop or collapse a loop to a set point with limits to loop growth or decay based on process changes. The loop effectively balances out any errors in the mill speed reference. A new speed reference is then sent to a control device in the mill to control rolling speeds to ensure that the speed of each mill stand is correct relative to the previous and/or subsequent one. As can be theorized, the speed reference is a calculated value and is subject to error.

The invention eliminates the need for the mechanical loop and its associated control. The loop is replaced by a simple laser velocimetry system described herein. A laser is placed between each of the laminator supports. This can include multi-roll machines but with a single drive motor.

Figure 2 shows an illustrative example of another embodiment of the loopless rolling mill arrangement 20 used in accordance with the invention. The loopless mill arrangement 20 includes a mill having a line 4, rolling stands STD13 and STD14, entry lasers L13i and L14i, and exit lasers L13o and L140. Note that the loopless arrangement 20 is similar to the loopless rolling mill arrangement 2 of FIG. 1. Each STD13, STD14 laminator holder includes one input laser L13i, L14i and one output laser L13o, L14o. The entry lasers L13i, L14i measure the entry speed of the product from the laminator to its respective rolling stand STD13, STD14. The output lasers L13o, L14o measure the output speed of the product from the rolling mill from its respective rolling stand STD13, STD14.

The roll product entry and exit speeds on each roll stand are compared to its theoretically controlled roll speed, as well as the entry and exit speed of a previous roll stand.

Using the invention and linking the actual speed of the rolling product to the control device of a rolling mill, one could further improve the control of auxiliary machines such as head and end shears, or achieve shorter crop lengths, reducing thus the loss of metallic yield.

In addition, the invention can allow the gap between rings in the area of the laying head of a rolling mill to be perfectly maintained from the head to the ends of the rolled product. Any change in product speed could be instantly adjusted using the lasers and cameras discussed here. Additionally, the information provided by the cameras and lasers can be used to devise a smart laminating system that requires less mechanical equipment. This can reduce building length and associated costs, as well as the cost of maintaining less equipment, and product quality is improved due to the overall increase in precise control of the mill nibs.

When metallurgical processes require a greater distance between supports due to the need for cooling and equalization, two non-contact gauges can be used, one at the exit of the first support of the rolling mill and another at the entrance of the next. This ensures that the control device takes into account any effects of cooling and drag.

Although the present invention has been shown and described with respect to various preferred embodiments thereof, various changes, omissions and additions to the form and detail thereof, may be made within, without departing from, the scope of the invention as defined by the appended claims. .

Claims (16)

1. A rolling mill for producing rolled product, said rolling mill comprising: a rolling line (4) that moves the rolling product; a plurality of rolling stands (STD13, STD14) which are coupled to the rolling line that receives the rolled product and rolls the rolled product; a plurality of speed measuring devices located near each rolling stand; each speed measuring device measures the speed of the rolled product as it passes through the speed measuring devices; and a control device that receives information associated with the speed measuring devices, characterized in that said control device adjusts the speed of the rolled product for any speed differential that may exist between any of the supports of the rolling mill, where the speed differential is the difference between the actual speed of the rolled product and a calculated speed at a point on the mill line. The rolling mill of claim 1, wherein the speed measurement devices comprise a laser (L12o, L13i, L13o, L14i, L14o) and a camera (C12o, C13o, C14o). The rolling mill of claim 2, wherein the camera (C12o, C13o, C14o) evaluates the quality of the rolled product. The mill of claim 3, wherein the laser (L12o, L13i, L13o, L14i, L14o) measures the actual product speed of the mill. The rolling mill of claim 1, wherein the speed measurement devices comprise a plurality of lasers (L12o, L13i, L13o, L14i, L14o). The laminator of claim 5, wherein the lasers (L12o, L13i, L13o, L14i, L14o) are arranged such that a selective number of the lasers are associated with each laminator holder (STD13, STD14). The laminator of claim 6, wherein the selective number of lasers (L12o, L13i, L13o, L14i, L14o) measure the product entry and exit rates of the laminator for their respective laminator support (STD13, STD14 ). The rolling mill of claim 1, wherein the control device increases or decreases the rolling speed of one or more rolling stands (STD13, STD14) to ensure that the rolling speeds are equalized to stabilize the rolling mill. 9. A method of producing roll product in a rolling mill, said method comprising: providing a rolling line (4) that moves the rolling product; providing a plurality of rolling stands (STD13, STD14) which are coupled to the rolling line that receives the rolled product and rolls the rolled product; placing near each rolling stand a plurality of speed measuring devices, each speed measuring device measuring the speed of the rolled product as it passes the speed measuring devices; and characterized by adjusting the speed of the roll product for any speed differential that may exist between any of the roll supports using a control device that receives information associated with speed measuring devices, wherein the speed differential is the difference between the actual speed of the rolling product and a calculated speed at a point on the rolling line. The method of claim 9, wherein the speed measurement devices comprise a laser (L12o, L13i, L13o, L14i, L14o) and a camera (C12o, C13o, C14o). The method of claim 10, wherein the camera (C12o, C13o, C14o) evaluates the quality of the rolling product. The method of claim 10 or 11, wherein the laser (L12o, L13i, L13o, L14i, L14o) measures the actual speed of the rolling product. The method of claim 9, wherein the speed measurement devices comprise a plurality of lasers (L12o, L13i, L13o, L14i, L14o). The method of claim 13, wherein the lasers (L12o, L13i, L13o, L14i, L14o) are arranged such that a selective number of the lasers are associated with each rolling stand (STD13, STD14). The method of claim 14, wherein the selective number of lasers (L13i, L13o, L14i, L14o) measure the feed-in and feed-out rates for their respective roll holder (STD13, STD14). The method of claim 9, wherein the control device increases or decreases the rolling speed of one or more rolling stands (STD13, STD14) to stabilize the rolling mill.