JPH05177224A - Method for rolling - Google Patents

Abstract

PURPOSE:To prevent the disorder of the shape of a rolled stock without using a complicated device such as a horizontal supporting roll and carry out rolling stably under high pressure. CONSTITUTION:In a method using a rolling mill where one or more pairs of rolls are arranged respectively under a contact state clamped a pair of upper and lower working rolls 2a, 2b, horizontal deflection produced in working rolls 2a, 2b during rolling are measured separately by displacement gages 7 and the rolling torques of driving rolls are adjusted separately to eliminate differences between horizontal deflections of the upper and lower working rolls according to the obtained value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for rolling using a rolling mill having a reinforcing roll and / or an intermediate roll sandwiching a pair of work rolls such as a quadruple rolling mill and a six-fold rolling mill. In addition, the present invention relates to a rolling method that enables more stable high reduction rolling.

[0002]

2. Description of the Related Art In recent years, rolling mills using work rolls having a small diameter have been operated for the purpose of increasing the rolling reduction during rolling and imparting high gloss to the rolled material after rolling. However, when the diameter of the work roll is reduced, the rigidity of the roll is reduced, so that a horizontal force along the rolling direction is generated on the work roll during rolling. The roll deflection in the direction along the horizontal force is significantly increased, and various adverse effects are exerted on the rolling operation. For example, there are problems that the shape of the rolled material is disturbed during rolling to cause drawing, and that the plate thickness is less likely to decrease even if the rolling load is increased.

In order to prevent such a problem, for example, in Japanese Patent Laid-Open No. 63-60004, a horizontal support roll for supporting the roll body of the work roll is installed to suppress the horizontal deflection of the work roll. How to do is described. However, when this method is used, the horizontal support roll has a complicated structure, and since the horizontal support roll has a split structure, the roll mark of the split roll is transferred to the work roll and further to the rolled material to obtain The rolled material has a problem that its surface quality is deteriorated and it cannot be a product.

Further, as a method for suppressing the horizontal deflection of the work rolls without using the above-mentioned horizontal support rolls, JP-A-60-106602 discloses that upper and lower work rolls are offset by the same amount. However, it has been proposed that the offset position is a position where the horizontal component of the rolling load acting on the work roll and the horizontal component of the tangential force acting on the work roll are balanced. This method is an effective method when the roll groups that are vertically opposed to each other with the rolled material in between are positioned in a completely symmetrical manner. However, in an actual rolling mill, there is an error in mechanical accuracy, so the upper and lower work rolls as shown in Fig. 1 (a) and / or the upper and lower work rolls in contact with the work rolls as shown in Fig. 1 (b). (For example, the reinforcing roll) has an error Δe (deviation from a symmetrical position) of the center line connecting the upper and lower roll axes. Thus, the contact angle between the work roll and the reinforcing roll is different between the upper and lower sides, and the horizontal component of the tangential force acting on the work roll and the horizontal component of the rolling load are different between the upper and lower work rolls, resulting in the horizontal deflection of the upper and lower work rolls. There is a difference in quantity. The difference in horizontal deflection is that the smaller the work roll diameter and the larger the roll body length,
Also, since the higher the rolling load is, the larger it is, the above-mentioned JP-A-60
If the offset position is determined without considering the center line error of the upper and lower rolls as in Japanese Patent No. 106602, the shape of the rolled material is disturbed and the rolling becomes impossible. In addition, the larger the load, the more the horizontal deflection of the upper and lower work rolls increases, making rolling impossible.

[0005]

However, in the actual rolling mill, which has an error in the center line connecting the upper and lower roll axes due to the error in mechanical accuracy as described above, there arises a difference in the horizontal deflection amount of the work rolls. SUMMARY OF THE INVENTION It is an object of the present invention to propose a rolling method that advantageously solves the above-mentioned problem and does not use a complicated device such as a horizontal support roll and that enables stable strong reduction rolling.

[0006]

SUMMARY OF THE INVENTION The present invention is a rolling method using a rolling mill in which a pair of upper and lower work rolls are sandwiched and a pair of or more rolls are arranged in contact with each other. The rolling method is characterized by individually measuring the deflections and individually adjusting the rolling torques of the drive rolls so as to eliminate the difference in the horizontal deflection amounts of the upper and lower work rolls based on the values.

[0007]

FIG. 2 shows the result of an examination of the horizontal deflection amount of the upper and lower work rolls with respect to the rolling load when the work roll has a center line error. In addition, the positive and negative signs of the horizontal deflection amount in the same figure are shown as the deflection of the work roll on the inlet side being positive and the deflection on the outlet side being negative. As is clear from the figure, as the rolling load increases, the difference between the horizontal deflection amounts of the work rolls at the top and bottom increases, and the greater the center line error Δe, the greater the difference between the horizontal deflection amounts. In addition, it has been confirmed that the smaller the work roll diameter and the longer the roll body length, that is, the smaller the work roll rigidity, the greater the difference in the horizontal deflection amount.

In view of the above findings, the present invention individually measures the horizontal deflection that occurs in the work rolls during rolling, and based on that value, the rolling torques of the drive rolls are individually adjusted in order to eliminate the difference in the horizontal deflection amount between the upper and lower work rolls. To adjust to.

For example, when the upper and lower work rolls are bent in the direction of the incoming side of the rolled material entering the rolling mill and the deflection amount of the lower work roll is larger than the deflection amount of the upper work roll, the lower work roll is subjected to the upper work due to a mechanical precision error. It is located in the direction of the entrance side of the rolling mill from the roll. Therefore, stable rolling can be performed by increasing the torque of the upper drive roll and decreasing the torque of the lower drive roll so that the horizontal deflections of the upper and lower work rolls are about the same.

The torque of the drive roll can be easily adjusted by adjusting the current of the motor for driving the drive roll.

[0011]

EXAMPLE FIG. 3 shows an essential part of an example of a rolling mill suitable for applying the method of the present invention using a four-high rolling mill as an example. Figure 3
In FIG. 1, 1 is a rolled material, 2a is an upper work roll, 2b is a lower work roll, 3a and 3b are upper and lower reinforcing rolls in contact with the upper and lower work rolls, respectively.
a and the lower work roll 2b are rotatably supported by work roll chocks 4a and 4b at their roll ends, and mounted on the housing 6, and the upper and lower reinforcing rolls 3a and 3b.
Similarly, at each roll end, reinforced roll chock 5
It is rotatably supported by a and 5b and attached to the housing 6. Reference numeral 7 is a displacement meter that measures the deflection of the rolls, and is provided for the upper and lower work rolls.

The principle of measuring the horizontal deflection of the roll will be described with reference to FIG. 4, in which the distance sensor 7a is opposed to the work roll at a distance greater than the amount of bending of the work roll. The distance sensor 7a measures the distance between the sensor and the surface of the work roll in a non-contact manner. The distance sensor 7a is provided at the center of the roll and the end of the roll, respectively. The horizontal deflection amount of the work roll is calculated by obtaining the difference in displacement between and. The distance sensor 7a may be arranged, for example, on a beam (not shown) extending between the roll chocks in parallel with the roll axis.

The displacement gauge is not limited to the above example, and a known displacement gauge can be used as appropriate.
Either a contact type or a non-contact type may be used.

The work rolls 2a,
The positional relationship between the upper and lower work rolls 2a and 2b can be grasped by comparing the horizontal deflection amount and the deflection direction of 2b in the vertical direction.

Table 1 shows an example of a method for individually adjusting the torque of the upper and lower drive rolls based on the measurement result of the horizontal deflection of the upper and lower work rolls 2a and 2b.

[0016]

[Table 1]

As shown in the table, when the upper work roll 2a and the lower work roll 2b are deflected in the outgoing direction of the rolling mill ().
Compares the horizontal deflections of the upper work roll 2a and the lower work roll 2b, and increases the rolling torque of the one with the larger horizontal deflection and decreases the rolling torque of the smaller one until the horizontal deflections of the upper and lower work rolls become equal. Let When the upper work roll 2a bends toward the exit side of the rolling mill and the lower work roll 2b bends toward the entrance side of the rolling mill (), the torque of the upper drive roll is increased and the torque of the lower drive roll is decreased. When the upper work roll 2a bends in the inlet side of the rolling mill and the lower work roll 2b bends in the outlet side of the rolling mill ()
Reduces the torque of the upper drive roll and increases the torque of the lower drive roll. When the upper work roll 2a and the lower work roll 2b are deflected toward the entrance side of the rolling mill (), the horizontal deflections of the upper work roll 2a and the lower work roll 2b are compared, and the horizontal deflections of the upper and lower work rolls are equal. The rolling torque with the larger horizontal deflection is decreased and the rolling torque with the smaller horizontal deflection is increased until it becomes.

By the above operation, the horizontal deflection amounts of the upper and lower work rolls are made approximately the same, and stable rolling becomes possible. In the above example, the rolling torque was adjusted by increasing or decreasing the upper and lower drive roll torques, but it may be adjusted by performing an operation of increasing or decreasing one of the upper and lower rolling torques. Needless to say.

Here, in a rolling mill as shown in FIG.
The steel sheet was rolled while increasing the rolling load for the invention example in which the rolling torque of the drive roll was adjusted and the conventional example in which the rolling torque of the drive roll was not adjusted. The amount of horizontal deflection of the upper and lower work rolls at that time is shown in FIG. 5, respectively. In the conventional example, the difference in horizontal deflection between the upper and lower work rolls increased as the rolling load increased, and the shape of the rolled material was suddenly disturbed at the rolling load of 1000 tonf, making it impossible to perform rolling. On the other hand, in the example of the present invention, the horizontal deflection of the upper and lower work rolls can be maintained at the same level, and sufficient rolling can be performed even when the rolling load is 1000 tonf or more.

[0020]

As described above, according to the present invention, the horizontal deflection that occurs in the work roll being rolled is individually measured, and the rolling torque of the drive roll is adjusted based on the measured horizontal deflection to eliminate the difference in the horizontal deflection amount between the upper and lower work rolls. By adjusting individually, the horizontal deflection amount of the upper and lower work rolls can be maintained at the same level without complicated devices such as horizontal support rolls for work rolls, which in turn disturbs the shape of the rolled material due to roll center line error. And stable rolling becomes possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship of forces acting on a work roll when a mechanical precision error exists.

FIG. 2 is a graph showing an influence of a rolling load on a horizontal deflection of upper and lower work rolls when a mechanical precision error exists.

FIG. 3 is an explanatory view showing a main part of an example of a rolling mill suitable for applying the method of the present invention.

FIG. 4 is an explanatory diagram of a principle of measuring a horizontal deflection of a roll.

FIG. 5 is a graph showing the relationship between the rolling load and the horizontal deflection amount of the upper and lower work rolls in the example of the present invention.

[Explanation of symbols]

 1 Rolled material 2a Upper work roll 2b Lower work roll 3a Upper reinforcement roll 3b Lower reinforcement roll 4a Upper work roll roll chock 4b Lower work roll roll chock 5a Upper reinforcement roll chock 5b Lower reinforcement roll chock 6 Housing 7 Displacement meter

Claims (1)

[Claims] 1. In a rolling method using a rolling mill in which a pair of upper and lower work rolls are sandwiched and a pair of or more rolls are arranged in contact with each other, the horizontal deflection occurring in the working rolls during rolling is measured individually, and A rolling method in which the rolling torques of the drive rolls are individually adjusted so as to eliminate the difference in horizontal deflection amount between the upper and lower work rolls based on the values.