JPH06277724A - Pair cross rolling mill having cross pin type spindle and rolling method therefor - Google Patents

Abstract

PURPOSE:To obtain a metallic plate excellent in accuracy of the plate thickness in the width direction by arranging cross pin type spindles as spindles to device work rolls in a pair cross rolling mill which can regulate and hold an angle between an upper work roll and a lower work roll. CONSTITUTION:The cross pin type spindles are arranged as the spindles driving the work rolls in the pair cross rolling mill. The variation of an angular velocity omega2 of the work rolls is calculated by using an angle alpha between a driving shaft and the spindle, an angle beta between the spindle and the work roll, a rotational angle phi of the driving shaft and an angular velocity omega1 of the driving shaft to correct and control the rotational velocity of a driving electric motor and to fix the angular velocity omega2 of the work rolls. Consequently, a spindle excellent in maintenance property can be adopted, the metallic plate excellent in accuracy of plate thickness in the width direction can be produced, the mill is compacted and the cost of equipment, too, can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pair cross rolling machine and a rolling method capable of producing a metal material having a good width direction thickness accuracy.

[0002]

2. Description of the Related Art Width thickness accuracy (hereinafter referred to as crown)
In order to improve the rolling stock, a rolling mill with high crown control capability has been developed (basic characteristics of cross rolling mill (PC mill), Mitsubishi Heavy Industries Technical Report Vol. 21 No. 6 1984-11). This type of rolling mill utilizes the fact that the upper and lower work rolls have an angle with each other and the surface distance between the upper and lower work rolls varies in the width direction. The drive of the work rolls of the rolling mill is generally as shown in FIG. 1, and the driving force is transmitted from the spindle to the work rolls.

The relative angle of the spindle and the work roll is not constant but complicatedly changed due to the rolling condition and the cross angle setting for crown control. Therefore, in the prior art, in order to keep the rotation speed of the work roll constant, a gear type spindle which is a constant velocity joint is adopted.

[0004]

Conventionally, a pair type cross rolling mill usually employs a gear type spindle which is a constant velocity joint, but a cross pin type spindle excellent in maintenance characteristics and equipment compactness cannot be used.
The reason is that in the cross pin type spindle, when an angle is generated between the spindle and the work roll, the angular velocity shown in the following equation is changed between the drive side and the work roll on the driven side.

Ω ₂ = ω ₁ (cos α cos β) / (1-sin ² β cos ² φ-sin ² α cos ² φ) (1) where ω ₁ ; drive shaft side angular velocity ω ₂ ; driven shaft side angular velocity φ: Drive shaft rotation angle α: Drive shaft-spindle angle β: Spindle-work roll angle

FIG. 3 shows how the angular velocity fluctuates depending on the angle between the spindle and the work roll. When the angular velocity fluctuates in the rolling mill, it becomes impossible to maintain a stable rolling state, resulting in plate thickness fluctuation, tension fluctuation, and the like.

It is an object of the present invention to provide a paired cross mill employing a cross pin type spindle useful as a spindle, and a rolling method for enabling normal rolling by the mill.

[0008]

DISCLOSURE OF THE INVENTION In order to apply a cross-pin type spindle, which has heretofore been inapplicable, as a spindle for driving a work roll of a pair cross mill, the present invention has been variously studied. The method of eliminating the adverse effect in the case of the spindle, that is, the fluctuation of the rotational angular velocity of the work roll by controlling the speed of the drive motor was developed and completed based on this method. FIG. 2 shows a cross pin type spindle.

The gist of the present invention is as follows. (1) In a pair cross rolling machine capable of adjusting and holding the angle formed by the upper work roll and the lower work roll,
A pair cross rolling machine characterized in that a cross pin type spindle is arranged on a spindle for driving the work rolls.

(2) When rolling using the pair cross rolling mill described in (1) above, the angle α between the drive shaft and the spindle, the angle β between the spindle and the work roll, the rotation angle φ of the drive shaft, and the drive shaft. the angular velocity omega ₁ to calculate the variation of the angular velocity omega ₂ of the work rolls with, by correcting control the rotational speed of the drive motor, rolling method characterized by constant angular velocity omega ₂ of the work rolls.

[0011]

[Examples] Table 1 shows the rolling mill specifications of the examples. It is a pair cross rolling mill that adopts a cross pin type spindle, and a cross angle of up to 1.2 degrees is possible. In this embodiment, an ordinary four-high rolling mill is modified into a pair cross mill. Since the drive motor, reduction gear, pinion stand, etc. were already used, the required maximum cross angle was 1.
If the angle is 2 degrees, the maximum angle between the spindle and the work roll will be 3.5 degrees. In the gear type spindle used in the conventional technology, the maximum angle is said to be 2.5 degrees because of its function, and it was not applicable. However, by adopting the rolling method of the present invention, it is possible to make the working roll rotational angular velocity constant even when a cross pin type spindle is used. That is, since the fluctuation of the angular velocity ω ₂ of the work roll can be geometrically predicted by α, β, and φ, the correction control of the angular velocity fluctuation was performed by the drive motor control system shown in FIG.

In FIG. 4, 1 is a multiplier, 2 is an adder,
3 is a speed controller, 4 is a power supply, 5 is a motor, 6 is a speed reducer,
A speed sensor 7 for the motor 5 is connected to the adder 2. 8
Is a calculator, and changes in the angular velocity ω ₂ of the work roll based on detection signals from the rotation angle detector 9 of the drive shaft, the angle detector 10 of the drive shaft and the spindle, and the angle detector 11 of the spindle and the work roll. Is calculated by the above equation (1) to obtain a correction value of the rotation speed of the drive motor, which is calculated by the speed controller 3
Is input to adjust and control the angular velocity of the work roll appropriately.

[0013]

[Table 1]

[0014]

By constructing and implementing the present invention as described above, it is possible to employ a spindle with good maintainability and to produce a plate material with a good plate thickness accuracy in the width direction. Alternatively, the equipment can be made compact and the equipment cost can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a drive system of a rolling mill.

FIG. 2 is an example of a cross pin type spindle,
(A) is a schematic diagram of its use, and (b) is a structural diagram of the spindle.

FIG. 3 is a diagram showing an angular velocity fluctuation depending on an angle formed by a spindle and a work roll.

FIG. 4 is an explanatory diagram showing a method of controlling a drive motor.

[Explanation of symbols]

 1 multiplier 2 adder 3 speed controller 4 power supply 5 motor 6 speed reducer 7 speed sensor 8 calculator 9 rotation angle detector 10 angle detector between drive shaft and spindle 11 angle detector between spindle and work roll

Claims (2)

[Claims] 1. A pair cross rolling machine capable of adjusting and holding an angle formed by an upper work roll and a lower work roll, wherein a spindle of a cross pin type is arranged as a spindle for driving the work roll. Pair cross rolling machine. 2. When rolling with the pair cross rolling mill according to claim 1, an angle α formed by the drive shaft and the spindle, an angle β formed by the spindle and the work roll, a rotation angle φ of the drive shaft, and an angular velocity of the drive shaft. Angular velocity of the work roll ω ₂ using ω ₁
The rolling method is characterized in that the angular velocity ω ₂ of the work roll is made constant by calculating the fluctuation of the above and correcting and controlling the rotation speed of the drive motor.