JPS6384709A - Method and device for shifting work roll in continuous rolling mill - Google Patents

Abstract

PURPOSE:To reduce local wears of a work roll, to improve the product profile, and increase the number of rolled stocks by controlling a shift amount so that a shift position of the former and latter rolling stands differs from each other. CONSTITUTION:A shift amount arithmetic means 17 calculates each work roll shift value at respective rolling stands F1-F6 for a steel stock to be rolled. Outputs from the means 17 inputted to each shift position correction means 19 connected to every work roll shift means 18 connected to a shift cylinder at respective rolling stands F1-F6. Those means 19 control so that a shift position of the stands F1-F6 calculated by the arithmetic means 17 differs from the position of the adjacent preceding and succeeding stands at the least. The means 18 shifts respective work rolls 2 and 2a according to an output value of the means 19.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention is for shifting work rolls in a continuous rolling mill.

b. Prior art The work rolls (usually referred to as work rolls, WR) in this type of continuous rolling mill that have been used in the past wear out the parts that come into contact with the steel by rolling the steel. As shown in Figure 8 (as in the case without Al work roll shift,
The product profile was as shown in (C). In particular, abnormal protrusions (produced by increased wear) occur on both edges of the work roll where wear is significant, and the profile of the rolled steel product becomes similar to the roll profile, resulting in It is common for abnormal protrusions or edge drops (extremely thinner plate thickness) to occur at the edges.

Furthermore, when a mixture of steel materials with different widths and thicknesses is fed and rolled in an out-of-order state using the same work roll, a special rolling schedule is set in order to avoid the occurrence of the abnormal profile in the finished product as described above. Special methods are employed for assembling or shifting work rolls.

As a special method as mentioned above, for example,
First, as a method of specially setting up a rolling schedule,
Although not shown in the drawings, this is a method in which the abnormally worn parts of the roll wear profile are prevented from coming into contact with the next rolled material by rolling from a wide material to a gradually narrow material.

The above-mentioned method is generally referred to as the schedule rolling method.

In addition, as a special method for shifting the work roll in its axial direction, as disclosed in FIGS. 9 and 10, the work roll is shifted in its axial direction to prevent abnormal wear ( This is a rolling method in which uneven wear (uneven wear) is dispersed and a uniform roll profile is obtained, and this method is generally referred to as a work roll shift rolling method.

Next, the above-mentioned work roll shift rolling method will be explained based on the above-mentioned FIGS. 9 and 10.

In FIG. 9, the steel material 1 is held between an upper work roll 2 and a lower work roll 2a, and each of the work rolls 2 and 2a
is configured to be movable in its axial direction, and is located on the drive side D.
The time when it moves to B is called the + (plus) direction, and the time when it moves to the work side WS is called the - (minus) direction. Further, these work rolls 2 and 2a are symmetrical to each other,
move in opposite directions.

For example, the amount of movement is as shown in Table 1 below.

In other words, the amount of movement is determined for each steel type, plate thickness, etc., and for each rolling stand, and in the case of ordinary steel with a plate thickness of 1.99n or less, the maximum value to be shifted is from rolling stand F1 to F1 in both the ten and one direction. +80 for F3, rolling stands F4 to F6
In this case, the shift width is ±50, and the shift width is shifted by 10 for each rolling.

At this time, MAX to shift each work roll 2 and 2a
The value is shifted MAX:l:xm, and the value to be moved every rolling is called shift pitch mtt. In this case, an upper back-up roll 3 and a lower back-up roll 3a are pressed against the outside of each of the work rolls 2 and 2a.

Furthermore, as shown in FIG. 10, the shift amount described above is defined as the cycle of moving from the zero position through the MAX values in ten directions in one direction, and then returning from the MAX value in one direction to the zero position. Among the shift amounts of one cycle, the shift amount of one stage is called one pitch.

C1 Problems to be Solved by the Invention As the conventional rolling methods, the schedule rolling method and the work roll shift rolling method have been adopted as described above, but these conventional methods have various problems, and the normal Product profiles were difficult to obtain.

(First of all, in the case of the scheduled rolling method, the sheet width is always rolled from wide to narrow, so control of the sheet width is extremely important. In practice, it is extremely difficult to completely control the board width schedule on the line and ultimately the delivery schedule to the user.In addition, it is extremely difficult to maintain a stable shape. It was necessary to increase the frequency of reshuffling work roles.

(2) In the case of the work roll shift rolling method, although the problems mentioned in the above-mentioned item 1 can be solved to some extent, there are still various problems. That is, it is impossible to freely roll various steel materials in random order without regulating the steel type, sheet width, sheet thickness, rolling amount, etc.

For example, when rolling each steel material with a shift pattern as shown in Table 1 above, the following important problems have occurred.

In the case of a1 width reverse rolling, when a large amount of narrow material is rolled while shifting the work rolls (referred to as a large rolling length), and then a wide material is rolled,
Due to rolling of the narrow material, if the edge of the wide material still comes into contact with the steeply sloped part of the work roll wear profile slope 6 shown in Fig. 8, the thickness of the material becomes extremely thin. , which causes edge elongation.

b. When the plate thickness is changed (in the case of sandwich rolling), the shift MAX value of thin materials is smaller than that of thick materials, but the reason for this is, for example, in the rear stands F4 to F6, the shift MAX value is smaller than that of thick materials. Since rolling is carried out at a high rolling reduction ratio, the edge part is rolled with the steep slope 6 of the work roll wear profile shown in Fig. 8, so the edge part becomes even thinner.
The edges were elongated, deteriorating the shape of the product, and abnormal protrusions were occurring at the edge portion 5 of the work roll profile.

Therefore, as shown in Fig. 11, steel materials with a plate thickness of 2M11 or more are used as pattern A with a shift l-MAX value ±100 balls, and thin steel materials with a plate thickness of 1.9 mm or less are used with a shift MAX value ±50 m.
When rolling these different steel materials alternately as pattern B, pattern B material shifts B material within a range that does not exceed the ±MAX value of pattern B, so now the personnel rolls at the shift position +65, Next, when material B is rolled, +5
I am taken back to 0. Next, when the human resources arrive, the human resources are shifted by +50, and the human resources are moved in the direction of 10 mg ( ), resulting in a shift value of l. Therefore, the human resources were set to have a value that was one pitch wider than the shift max value of material B. In other words, even if the pattern personnel had set the shift MAX value to 100 dragons, they had taken steps to make it return to the MAX value of the pattern B material, in order to solve the problem of edge elongation that occurs when thin materials are stiffened. .

However, in the conventional shift method to solve the above-mentioned problems, even if the MAX value is set for each steel material, the MAX value is constrained by other patterns, so the overall shift amount is narrowed. As a result, the roll wear dispersion effect is weakened, and the shape of the product is deteriorated because various steel materials with different patterns are rolled in random order without any restrictions.

Therefore, to summarize the various problems mentioned above, in the conventional roll shift rolling method, when the rolling amount increases,
Problems occur when width reverse rolling or when the plate thickness is changed to thinner products, and even if a shift pattern is set for each steel material, it is not possible to control the shift according to the pattern, and as the amount of rolling increases, no regulations are implemented. It was impossible to roll various steel materials in random order without any problems.

In other words, although roll shifting is performed to disperse uneven wear on the work rolls, uneven wear occurs on the rolls as the amount of rolling increases. If this uneven wear also occurs at the same position on the roll of the subsequent stand, the product will develop an abnormal shape due to the uneven wear. This state is as shown in FIG.

The present invention has been made to solve the above-mentioned problems, and it shifts the pattern for each steel material almost exactly as it is for each rolling stand, and at least shifts the shift positions of the front and rear rolling stands to be different. It is an object of the present invention to provide a method and apparatus for shifting work rolls in a continuous rolling mill for correcting the abnormal profile and preventing it from appearing in finished products.

d. Means for Solving the Problems The method for shifting work rolls in a continuous rolling mill according to the present invention involves shifting each work roll of a continuous rolling mill consisting of a plurality of rolling stands in its axial direction to carry out rolling. A method for shifting work rolls in a continuous rolling mill ζ includes at least a step of determining a pattern for shifting each work roll based on the steel type, sheet width, sheet thickness, etc., and a step of shifting each work roll based on the pattern. This method includes the step of correcting the shift positions of the front and rear rolling stands to be different from each other.

Further, another invention is a work roll shift device for a continuous rolling mill, which is used in a continuous rolling mill that performs rolling by shifting each work roll of the continuous rolling mill consisting of a plurality of rolling stands in its axial direction. In the work roll shift device, a pattern storage means for storing a pattern for shifting the work roll according to the steel type, plate width, plate thickness, etc., and a pattern corresponding to the steel type rolled by each of the work rolls are selected. a shift position storage means for detecting the shift position of the work roll during the rolling and storing the detected value; Based on the information, the shift amount calculation means for calculating the work roll shift value of each rolling stand for the steel material to be rolled this time, and the shift position of each rolling stand calculated by the calculation means, are determined to be at least the shift positions of the front and rear rolling stands. a shift position correcting means for correcting the shift amount of each of the rolling stands so that the shift position is different from that of the rolling stand; and a work roll shifting means for shifting the work roll in response to a signal from the shift position correcting means. Become,
This configuration is such that at least the shift positions of the front and rear rolling stands are corrected to be different from each other.

f. Examples Hereinafter, one embodiment of the method and apparatus for shifting work rolls in a continuous rolling mill according to the present invention will be described in detail with reference to the drawings.

First, FIG. 1 to FIG. 7 are for showing a method and apparatus for shifting work rolls in a continuous rolling mill according to the present invention, and FIG. 1 is a block diagram showing the overall configuration. What is indicated by the reference numeral 1 is a steel material that is continuously fed, and this steel material 1 is supplied to six rolling stands F to No. 6.
It is configured to be rolled through each roll section 10 provided at F1 to F6.

Among the aforementioned roll sections 10, the first to third rolling stands F
Each roll section 10 in No. 1 to F3 is composed of upper and lower work rolls 2 and 2a and upper and lower back rolls 3 and 3a, and each roll section 10 in No. 4 to No. 6 rolling stands F4 to F6 is composed of upper and lower work rolls 2 and 2a and upper and lower back rolls 3 and 3a. An intermediate roll 11 is provided between each of the work rolls 2 and 2a and each of the backup rolls 3 and 3a.

Further, reference numerals 12 and 16 indicate pattern storage means and pattern selection means connected to a host computer 14 for controlling the entire apparatus. The pattern selection means can store patterns for shifting the work rolls 2 and 2a, and select a pattern corresponding to the type of steel to be rolled by the work rolls 2 and 2a.

Each of the aforementioned rolling stands F1 to F6 is provided with shift position detection means 15 connected to a pulse generator 24 (described later) for detecting the shift position of each of the work rolls 2 and 2a. The detection value from the shift position detection means 15 is determined by each work roll 2 and 2a during rolling.
shift position storage means 16 for storing the shift position of
has been entered.

The above-mentioned pattern storage means 12 and pattern selection means 13
The information (data) from the shift position storage means 16 is input to the shift amount calculation means 17.

This shift amount calculation means 17 calculates each work roll shift value of each rolling stand F1 to F6 of the steel material to be rolled this time based on the above-mentioned information.

The output from the shift amount calculating means 17 is applied to each shift position correcting means 19 connected to each work roll shifting means 18 connected to a shift cylinder 21 shown in FIG. 5, which will be described later, in each rolling stand F1 to F6. has been done. Each of these shift position correction means 19 controls the shift position of each of the rolling stands F1 to F6 calculated by the calculation means to be a shift position different from at least the shift position of the front and rear rolling stands, and The work roll shifting means 18 shifts each work roll 2 and 2a according to the output value of the shift position correction means 19.

Furthermore, an example of the shift structure of the work rolls 2 and 2a described above is as shown in FIG. 5, and a pair of shift levers 20 are provided at one end of the work roll 2. , a shift cylinder 21 is connected to each shift lever 20, respectively.

A gear portion 22 is formed at the lower end of one of the shift levers 20, and a rotary gear 23 is meshed with this gear portion 22. The rotation speed of the rotary gear 23 is read by a pulse generator 24 to determine the shift position. and the amount of shift.

The method and apparatus for shifting work rolls in a continuous rolling mill according to the present invention are constructed as described above, and the operation thereof will be explained below.

First, when starting rolling, each rolling stand F1 to F6
The shift positions of each work roll 2 and 2a are shifted as much as possible from the initial position of the cycle as shown in FIG. 3, that is, the phase of the cycle of each pattern is shifted. and a pattern is set for each 2a.

Now, 1, which is a thin material of ordinary steel listed in Table 1 above,
The pattern of 9n plate thickness is designated as pattern A, the pattern of 2 and OR plate thickness of thick materials is designated as pattern B, and the pattern of 2.0 inch plate thickness of special steel is designated as pattern C.
The movement of each work roll 2 and 2a of rolling stand F4 will be explained based on FIG. 4.

In the above case, the shift pitch is 10m with the shift l-MAX value of pattern A being ±5°n, and the shift MAX value of pattern B being ±5°n.
10on shift pitch 25B1 pattern C shift M
The shift pitch is 1°zII+ with AX±80in.

Here, when rolling the human resources and material B alternately, when the first material to be rolled has pattern A, it is shifted in the 10 m5++ direction and rolled. When the second rolled material is pattern B,
It is shifted to a position moved 25 inches from the 0 position, that is, a position moved 15 m+ from the first position.

Now, if the shift pitch of pattern B is 6 battles, the positions from 0 position to 6H and the position of 12 dragons will be shifted, but in this case, the shift pitch will be in the same direction as pattern A, that is, 10 dragon positions. 12111, which is the closest position to the first shift position. In other words, rolling is performed by moving the first roll in the second + direction.

After that, as shown in FIG. 4, pattern A is shifted in pattern A, the rolled shift position is detected, and this detected value is stored in the shift position storage means 16, and when rolling the next material A, , joO shift to the previously rolled position and rolling. In this case, the same operation is performed for pattern B as well.

Next, after rolling the 11th grain B material, if the 15th grain is rolled for the first time in pattern C, the 14th grain B
Material C is rolled in the same direction as , that is, in the direction of moving from the shift MAX+ side to the zero position, and shifted to the position closest to the 14th shift position on pattern C.

Thereafter, the shift position at which each pattern was rolled is memorized, and when rolling the next pattern material, each shift pitch is moved to the previous shift position.

In other words, according to the above-mentioned shift method, when A<, which is constrained by the MAX value of another pattern,
Therefore, it is shifted according to the setting. In order to prevent the product profile from deteriorating due to the work roll wear profile as much as possible, the shift position of each rolling stand is corrected while making sure that the shifting positions of the front and rear rolling stands are not the same.

We will explain how to correct it.

Now, change the shift position of the fourth rolling stand F4 with the n grain to W4.
(n), the shift position of the fifth rolling stand F5 is changed to Ws(n
). Also, the n+1st 0 position is W4(m-)-1)
and W5(n-1-+), and then the preset separation constant between each rolling stand (shift position difference between each rolling stand) is determined as follows.

IWs(n-)-+) 1-IW4(hh-h)l
≧K(1))ws(n-1-+)l-lW4(a-h
)l<K (2) In the case of (1) above, W
5(n+1) and W4(r*+1) with the fourth and fifth values.
The shift positions of rolling stands F4 and F5 are determined,
In the case of (2) above, control is performed to advance the shift position of the fourth rolling stand F4 by several pitches until the condition of (1) is met. Note that this control is performed similarly in the case of the third rolling stand F3.

Further, the above-mentioned constant may be determined for each pattern, but according to past experimental examples, a range of about 5 to 20 dragons is suitable.

The outline of the control flow described above is as shown in FIG. 2, starting from the step of setting various patterns, shifting the work rolls 2 and 2a, detecting their shift positions, and storing the shift position storage means. The storing step is shown at 16.

Furthermore, although the shift position storage means 16, shift amount calculation means 17, pattern storage means 12, pattern selection means 13, shift position correction means 19, etc. shown in this embodiment are shown in an independent state, Needless to say, it can be used built-in in a computer.

Furthermore, FIG. 6 shows the characteristics of the roll wear profile in the sixth rolling stand F6 obtained by the above-mentioned work roll shifting method and apparatus, comparing the results with no work roll shift and with the conventional work roll shift. At the same time, improvements in the characteristics of the coil cross-sectional profile were also revealed.

Also, FIG. 7 shows the third stand Fs and the fourth stand F4.
The figure shows the limited number of rolls to be rolled in the present invention and the conventional method, and the increasing state of the limited number of rolls to be rolled is clarified.

g0 Effects of the Invention Since the method and device for shifting work rolls in a continuous rolling mill according to the present invention have the above configuration and operation, at least the shift positions of the front and rear rolling stands are different from each other. Since the shift amount is controlled, even when steel materials with different thicknesses and widths are fed and rolled in random order, the shift M of the set pattern is always maintained.
It was possible to use it to the maximum within the AX value, significantly reducing local wear of the work rolls, greatly improving the product profile, and also significantly increasing the number of rolls rolled.

[Brief explanation of the drawing]

Figures 1 to 7 are for showing the work roll shifting method and device in a continuous rolling mill according to the present invention. Figure 1 is a block diagram showing the overall configuration, and Figure 2 is a control flow. Fig. 3 is a cycle diagram showing the shift position, Fig. 4 is a characteristic diagram showing the roll shift position, Fig. 5 is a configuration diagram showing the main parts of Fig. 1 in detail, and Fig. 6 is a conventional example. A characteristic diagram showing the roll wear profile and a coil cross-sectional profile according to the present invention, FIG. 7 is a characteristic diagram showing the conventional example and the limited rolling number according to the present invention, and FIGS. 8 to 13 are for illustrating the conventional example. Fig. 8 is a characteristic diagram showing the roll wear profile and finished product profile, Fig. 9 is a configuration diagram showing the rolling stand, Fig. 10 is a characteristic diagram showing the shift cycle of work rolls, and Fig. 11 is a characteristic diagram showing plate thickness and work. FIG. 12 is a characteristic diagram showing the roll shift relationship, FIG. 12 is a characteristic diagram showing the roll wear profile, and FIG. 13 is a characteristic diagram showing the finished product and the wear profile. 1 is a steel material, 2 and 2a are work rolls, 3 and 3a are backup rolls, 11 is an intermediate roll, 12 is a pattern storage means, 16 is a pattern storage means, 14 is a host computer, 15 is a shift position detection means, 16 is a shift 17 is a shift amount calculation means, 18 is a work roll shift means, and 19 is a shift position correction means. Figure 2 (flowchart) Figure 3 Figure 4 Work roll shift Figure 8 Figure 9 Figure 10 One round

Claims (2)

[Claims] (1) In a work roll shifting method in a continuous rolling mill in which each work roll of a continuous rolling mill consisting of a plurality of rolling stands is shifted in the axial direction to perform rolling, depending on the steel type, plate width, plate thickness, etc. It consists of a step of determining a pattern for shifting each work roll, and a step of correcting so that at least the shift positions of the front and rear rolling stands are different from each other when shifting each of the work rolls based on the pattern. A method for shifting work rolls in a continuous rolling mill, characterized by: (2) In a work roll shift device in a continuous rolling mill that shifts each work roll in the axial direction of a continuous rolling mill consisting of a plurality of rolling stands to carry out rolling, it is possible to pattern storage means for storing a pattern for shifting the work rolls; pattern selection means for selecting a pattern corresponding to the type of steel rolled by each of the work rolls; and shifting of the work rolls during the rolling. A shift position storage means for detecting the position and storing the detected value, and information from the pattern storage means, pattern selection means, and shift position storage means determine the work roll shift value of each rolling stand for the steel material to be rolled this time. and a shift amount calculation means for calculating the shift amount of each of the rolling stands so that the shift position of each of the rolling stands calculated by the calculation means is a shift position that is different from at least the shift positions of the front and rear rolling stands. and a work roll shifting means for shifting the work roll in response to a signal from the shift position correction means,
A work roll shift device for a continuous rolling mill, characterized in that the shift positions of at least the front and rear rolling stands are adjusted to be different from each other.