JPH03204110A - Method for preventing meandering in pinch roll - Google Patents

Abstract

PURPOSE:To prevent meandering in a pinch roll by specifying the crown quantity of pinch roll for strip steel with a specified width and providing a guide roll. CONSTITUTION:The crown quantity DELTA c, which is shown in the formula, of a pinch roll 1 of which the roll width Wp (mm) is Wp >= 2.0 Ws to the width Ws (mm) of a strip steel 2 to be pinched is regulated within the range of -15 <=DELTA c X Ws (mm<2>) <= 15. Further, at the position on the inlet side of the pinch roll 1 where the distance L (mm) from the center of the pinch roll 1 becomes L / Ws <= 20, the guide roll 3 for constraining the moving of the strip steel 2 is provided. In this way, meandering in the pinch roll can be prevented. In the formula, De and Dc are respectively the roll diameter in the end part and middle part of the pinch roll.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for preventing meandering in pinch rolls in a steel plate manufacturing process or a steel strip conveying process.

(Prior Art) Generally, in the manufacturing process of steel plates or the conveyance process of steel strips, one or more pairs of upper and lower pinch rolls are installed for the purpose of ensuring tension during rolling, ensuring conveying force of the steel plate, etc.

In this pinch roll, particularly when the width of the material is smaller than the width of the pinch roll, meandering may occur due to uneven thickness of the material in the width direction of the camber 1 material, unbalanced pressure of the pinch roll, etc. was there. In particular, this problem becomes unavoidable when the rolling down mechanism is made hydraulic for reasons such as increasing the rolling load or improving operability.

This meandering is more likely to occur when the width of the steel plate is smaller than the width of the pinch rolls, or when the rolling load is larger. Meandering is particularly likely to occur when the steel strip is a narrow material, or when it is necessary to forcefully roll down the steel strip, using hydraulic pinch rolls installed on the output side of the line. A problem occurred in that the steel strip was protruded from the roll side, making it impossible to continue conveying the steel strip.

Conventionally, various studies have been conducted on the phenomenon of meandering in rolling rolls when rolling steel plates.
For example, a theoretical analysis such as that described in "Collection of Papers of the 1985 Plastic Processing and Cutting Conference" published by the Japan Society for Plastic Processing has also been conducted.

In addition, regarding countermeasures, for example,
Various meandering correction methods have been proposed as shown in Japanese Patent Publication No. 247 and Japanese Patent Publication No. 59-16527.

However, these methods are applied when rolling steel sheets, and when rolling within the elastic range such as with pinch rolls, the meandering mechanism is fundamentally different from that in rolling, and countermeasures are required. cannot be applied as is.

(Problems to be Solved by the Invention) As mentioned above, pinch rolls have problems such as non-uniform thickness in the width direction of the steel plate being pinched, camber in the machining/saw parts, and fluctuations in gears and knobs on the left and right sides of the pinch roll. Due to the
There is a problem in that meandering occurs and it becomes impossible to transport the steel plate stably.

(Means for Solving the Problems) The present invention provides a pair of upper and lower pinch rolls in which the rolling down mechanism is hydraulic. (unit d II + 1) is W
In the pinch roll where p≧2 and 0 Ws, the crown amount ΔC expressed by the following formula is set in the range of −15≦Δc−Ws (unit: mm2)≦15, and furthermore, the distance L ( A guide roll for restraining the steel strip from moving in the width direction and vertical direction of the steel strip is installed at a position on the input side of the pinch roll such that L/Ws≦20 (unit: m+e) is satisfied. This is a method for preventing meandering in pinch rolls.

Δc = (Dc - De)/2 Here, De = roll diameter at the end of the pinch roll (unit: m + 5) D
c: Roll diameter at the center of the vinyl roll (unit: m + *) (
Function) The present invention will be explained in detail below based on the figures.

FIG. 1 is a convex pinch roll applied to the present invention, FIG. 2 is a top view of the arrangement of the convex pinch roll and guide roll applied to the present invention, and FIGS. 3 and 4 are guides of the present invention. Examples of roll types; FIG. 5 is a schematic diagram showing the meandering suppression function of the concave pinch roll of the present invention; FIG. 6 shows experimental results when meandering was intentionally applied.

Normally, when rolling a steel strip, it is said that due to unbalanced pressure of the steel strip and asymmetric rolling on the left and right sides due to camber, etc., a difference in speed between the rolls and the left and right steel strips on the exit side occurs, causing meandering. On the other hand, with pinch rolls, the steel plate is basically only deformed within the elastic range due to rolling, so although there is a speed difference between the left and right sides in the part that is in contact with the rolls, the speeds on the entry and exit sides are equal. It has become.

The present inventors have discovered that even a slight difference in edge elongation within the elastic range of the roll contact area can cause problems, especially when the width of the steel strip is narrow or when the rolling load is large, as shown in Figure 6. It was revealed that meandering occurs.

In particular, if the rolling mechanism is hydraulic in order to increase the rolling load or improve operability, meandering is extremely likely to occur because the roll gap fluctuates due to unevenness of the material in the width direction. .

Here, in the present invention, in order to eliminate the difference in expansion between the left and right sides, the first
As shown in the figure, it is desirable that the roll shape is convex.

In this case, the contact area between the roll and the steel strip is limited to the vicinity of the center of the steel plate and does not come into contact with the edge, so the above-mentioned difference in elongation between the left and right edges hardly occurs, and meandering is reduced.

However, if an excessive amount of crown is applied, meandering force is likely to occur due to fluctuations in the roll gap, and the amount of rolling required to secure pinching force increases, causing problems as the central part is rolled. be.

Therefore, when the pinch roll is a convex crown roll, the upper limit of the crown amount AC is Δc-Ws≦15 (unit: d)
was set. Thereby, the amount of meandering can be considerably reduced.

However, due to changes in the roll gap during conveyance of the steel plate, it may be impossible to completely reduce the meandering amount to zero.

For this purpose, it is effective to install side guide rolls to prevent the steel plate from meandering. Here, since a type of guide that only prevents movement in the width direction may cause the steel plate to escape in the vertical direction, we chose a type that can also prevent movement in the vertical direction.

Here, FIG. 3 shows a type that uses both side rolls and presser rolls, and FIG. 4 shows a type in which movement in the vertical direction and width direction is restrained by one roll.

Note that the type shown in FIG. 4 is preferable in consideration of compatibility when the width of the steel plate to be pinched changes and the size of the rolls described later.

In addition, since it is better for the position of this guide roll to be as close as possible to the pinch roll, the distance between the pinch roll and the guide roll was limited to L/Ws≦20.

Note that in order to reduce the distance, it is desirable to reduce the size of the guide roll.

Furthermore, if a guide roll is installed on the extension 1 of the pinch roll, it basically has no function to prevent meandering, so it is essential to install it on the entry side of the pinch roll. Also,
If the movement of the steel plate is restrained in this way, it seems that the edge of the steel plate will be damaged by the meandering force, but there is no risk of this by setting the distance between the pinch roll and the guide roll to L/Ws≦20. .

On the other hand, in the present invention, it is also possible to use a concave crown roll or a flat roll instead of the convex crown roll as the pinch roll.

In the case of concave rolls, the difference in elongation between the left and right sides is more likely to occur because it is limited to the contact area or edge area between the roll and the steel plate.
When the unbalanced pressure is increased, a force is exerted to suppress meandering as shown in FIG. 5, so that it is possible to reduce the amount of meandering as a result.

However, if an excessive amount of crown is given, the edge portion will be rolled and cause camber of the steel plate, so the lower limit of the amount of crown is ΔC-Ws≧15 (unit: mm2)
And so.

Also in this case, it is essential to install side guides as in the case of convex rolls. Furthermore, even when flat rolls are used, meandering can be completely prevented by installing guide rolls.

However, considering problems such as roll wear, it is most desirable to use a convex roll.

(Example) Table 1 shows the test results when the present invention is applied and when the present invention is not applied when the steel strip is pinched by intentionally giving a gap difference between the left and right sides in order to generate a meandering force. It is something.

Here, the width of the pinch roll is 400 mm,
The pinch load was kept constant at 4 tons, and the width of the steel plate was 50-3.
The test was conducted by changing the volume to 50ml.

Note that types I and II of the guide rolls in the table indicate the types shown in FIGS. 3 and 4, respectively.

Meandering is completely prevented by using -15≦Δc-WS (unit: mm2)≦150-ru and installing a guide roll on the entrance side.

/ (Effects of the invention) As described above, by applying the present invention, in particular,
It is possible to completely eliminate meandering in pinch rolls, which is a problem when narrow width materials or heavy pressure is required, and the steel plate can be transported stably.

[Brief explanation of drawings]

FIG. 1 is a convex pinch roll applied to the present invention, FIG. 2 is a top view of the arrangement of the convex pinch roll and guide roll applied to the present invention, and FIGS. 3 and 4 are guides of the present invention. Examples of roll types; FIG. 5 is a schematic diagram showing the meandering suppression function of the concave pinch roll of the present invention; FIG. 6 shows experimental results when meandering was intentionally applied. 1. Convex pinch roll 2. Drawing of steel strip 3, guide roll 4, concave pinch roll agent and patent attorney Tatsuo Chanoki
(No change in content) Figure 1 (cL) Cb) (C) Figure 5 ((1) (b) 0 Procedural amendment form) February 16, 1990] Display of 2 cases 1999 Patent Application No. 343409 2, Name of the invention Method for preventing meandering in pinch rolls 3, Relationship with the case of the person making the amendment Patent applicant address 2-6-3 Otemachi, Chiyoda-ku, Tokyo Name (6
65) Nippon Steel Corporation Representative Yutaka Saito 4, Agent

Claims (1)

[Scope of Claims] Width Ws (unit: mm) of a steel strip to be pinched among a pair of upper and lower pinch rolls with a hydraulic rolling down mechanism.
When the roll width Wp (unit: mm) is Wp≧2.0W
In the pinch roll which is s, the crown amount Δc expressed by the following formula is -15≦Δc・Ws (unit: mm^2)≦1
5, and furthermore, the distance L from the center of the pinch roll
A guide roll for restraining the movement of the steel strip in the width direction and vertical direction of the steel strip is installed at a position on the input side of the pinch roll such that L/Ws≦20 (unit: mm). A method for preventing meandering in pinch rolls. Δc=(Dc-De)/2 Here, De: Roll diameter at the end of the pinch roll (unit: mm) Dc
: Roll diameter at the center of the pinch roll (unit: mm)