JPS5916524B2 - Rolling mill drive device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a driving device for a rolling mill that efficiently rolls a flat metal plate.

Generally, when rolling a flat metal plate, if the plate thickness is relatively thick, the amount of reduction or reduction rate that can be achieved in one rolling is limited by the torque that can be transmitted by the rolling mill, and if the plate thickness is thin, the rolling mill's Shape control is possible limited by rolling force.

Metal flat plate rolling is generally carried out by passing the metal flat plate between two work rolls 1 and 2 rotating in opposite directions, as shown in FIG.

In this case, the work rolls 1 and 2 generally have the same diameter and are driven together at the same circumferential speed.

3 and 4 are backup rolls.

By the way, if an appropriate tension is applied to the flat metal plate by the work rolls 1 and 2 and the circumferential speed of the work rolls 1 and 2 is brought to the true speed, the rolling force will be significantly reduced, but the driving torque will be significantly increased. .

As a method for easily obtaining a different circumferential speed rolling mill from a drive device of a constant circumferential speed rolling mill, as shown in FIG.
The electric motors 7,
8 are connected to form a twin electric motor system.

In the case of constant circumferential speed rolling, the speeds of the electric motors 7 and 8 can be controlled so that the circumferential speeds of the work rolls 1 and 2 are the same.

However, in the case of rolling at different circumferential speeds, simply controlling the electric motors 7.8 to achieve a predetermined speed ratio has the following disadvantages.

That is, among the electric motors 7.8, the motor on the high speed side works as a normal electric motor, but the motor on the low speed side acts as a brake, so that the rolling energy works only by the difference between them.

Therefore, as in a conventional rolling mill, if the motors 7 and 8 have the same capacity, the motor on the high speed side trips first, and the capacity of the motor on the low speed side cannot be fully utilized.

In addition, if it is impossible to roll a relatively thick plate that requires a large amount of electric power, and if it is necessary to transmit a large torque, the spindle 5
, 6 had the disadvantage that rolling was impossible due to insufficient strength.

The present invention provides a driving device for a rolling mill that does not have such drawbacks and is capable of performing true-speed rolling. In a rolling mill that performs rolling, electric motors are connected to each of the two work rolls individually, and the capacity of the electric motor connected to the work roll with the faster circumferential speed among the two work rolls at the front station is expressed as the circumferential speed. The comb has a capacity larger than the capacity of the electric motor connected to the slower work roll, and the capacity of the electric motor connected to the work roll with faster circumferential speed and the capacity of the electric motor connected to the work roll with slower circumferential speed. It is characterized in that the sum of the capacities of the electric motors is the same as the sum of the capacities of two electric motors of equal capacity in the case of a constant velocity rolling mill.

The gist is the driving device of a rolling mill, etc.

Next, the principle of the present invention will be explained with reference to FIG.

Figure 3 shows the rolling pressure distribution generated in the material being rolled. 1 is the upper work roll, 2 is the lower work roll, and 9 is the rolled material. In normal constant speed rolling, the neutral point is 0 point. There is a so-called friction hill A/ with the 0 point as the apex.
Can do c / B /.

The rolling force in this case is expressed by the area surrounded by OA'C'B'0'.

On the other hand, when the circumferential speeds of the upper and lower work rolls 1 and 2 are made true, for example, when the lower work roll 2 is made faster than the upper work roll 1, the neutral point moves to point D for the upper work roll 1. On the lower work roll 2, the friction hill moves to point E and becomes A'D'E'B'.

Therefore, the rolling force is expressed by the area surrounded by OA'D'E'B'O', and the rolling force expressed by the area D'C'E' is reduced compared to the case of constant speed rolling. Become.

The magnitude of the friction hill A'C'B' shown in FIG. 3 varies greatly depending on rolling conditions, and FIG. 4 shows the relationship between rolling conditions, rolling force, and rolling torque.

In FIG. 4, the vertical axis in the upper diagram represents rolling force, and the vertical axis in the lower diagram represents rolling torque.

V again.

is the circumferential speed of the low-speed side roll, vl is the circumferential speed of the high-speed side roll,
Vl/VO on the horizontal axis represents the speed ratio of the two work rolls 1.2.

Schedule I, shown by the dotted line, has a relatively thick board;
This is a rolling schedule in which the friction hill is small and the rolling torque is large, and the schedule ■ shown by the solid line is a schedule in which the plate thickness is thin, the friction hill is large, and the rolling torque is small.

In addition, To is the maximum torque per work roll of the conventional twin-motor type rolling mill shown in Fig. 2, and if the upper and lower work rolls are equipped with motors of the same capacity, The maximum drive torque for both work rolls is T
.

It is. In FIG. 4, when the plate thickness of schedule ■ shown by the solid line is thin, the friction hill is large, and the rolling torque is small, the electric motor 7 of FIG.
, 8 have the same capacity W.

Then, the limit at which the work rolls 1 and 2 can be made at true speed is when the work roll torque on the high speed side reaches TA, and the rolling force reduction effect at that time decreases from Po to pA.

Although the total capacity of both motors 7 and 8 is equal, the capacity W1 of the high-speed motor is made larger than the capacity W2 of the low-speed motor, that is, Wl>W2, Wl+W2""2W.

In this case, since the torque can be increased to TB, the rolling force reduction effect can be further increased to pB.

On the other hand, if this is done, the torque of the motor on the low speed side will be T'
Since the value increases from A to T'B with a negative value and larger power generation can be performed, power recovery becomes an important factor from the viewpoint of energy saving.

The present invention utilizes such a principle, and an embodiment of the first invention will be described with reference to FIG. so that the circumferential speeds of work rolls 1 and 2 are different, the work roll 1 side is made high speed, and the capacity of the electric motor 7 connected to the high circumferential speed work roll 1 side is changed to the low circumferential speed work roll 1 side. The electric motor 2 has a capacity larger than that of the electric motor 8 connected to the electric motor 2, and is provided with a device 10 for recovering electric power generated by the electric motor 8 and supplying electric power to the electric motor 7.

In the embodiment shown in FIG.
The motors 7 and 8 are directly connected to each other by spindles 5 and 6, but a reduction gear may be inserted between the motors 7 and 8 and the work rolls 1 and 2 to connect them. A so-called backup roll drive system may be used in which the backup rolls 3 and 4 are each connected to an electric motor and the work rolls 1 and 2 are driven via the backup rolls 3 and 4.

Considering the case of schedule I in FIG. 4 for the apparatus of the first invention, schedule I is a case in which it is more advantageous not to make any difference in capacity between the electric motors 7 and 8.

That is, if the electric motors 7 and 8 have the same capacity, rolling is possible, but if the maximum torques are selected to be TI and T2, respectively, the torque on the low circumferential speed side is T.

The circumferential speed ratio Vr/V until. If it is not increased, the motor will trip, and on the other hand, on the high circumferential speed side, the circumferential speed ratio can only be increased until the torque is below TD.

Therefore, rolling becomes impossible. The second invention deals with such a rolling schedule, and one embodiment thereof will be described with reference to FIG. 6.

In FIG. 6, the same reference numerals as in FIG. 5 indicate the same parts, and the difference is that a switching gear type speed tuning device 12 is provided between the work roll 1. When the gear type speed tuning device 12 performs its function, it is desirable that the motor 7 should be controlled in rotational speed and the motor 8 should be controlled in current, so a control device 11 is added to perform these controls.

7 and 8 show details of the switching gear type speed synchronizing device 12, in which one side of the shaft 13 is connected to the spindle 5 of FIG. 6, and the other side is connected to the work roll 1.

Further, the shaft 16 is connected to the spindle 6 and the work roll 2.

14 and 15 are gears, the gear 14 is fixed to the shaft 13, the gear 15 is rotatably fitted to the shaft 16, and the gears 14 and 15 always mesh with each other.

A small diameter gear 19 is integrally provided on one side of the gear 15, and a gear 17 having the same diameter and pitch as this gear 19 is fixed to the shaft 16 so as to be aligned with the gear 19.

Reference numeral 18 denotes an internal gear which meshes with the gear 17 and is capable of sliding left and right.

That is, as shown in FIG. 8, a rotatable shaft 26 is fitted into a bearing 25 disposed at a predetermined position, a yoke 27 is fixed to the shaft 26, and the yoke 27 is connected to a hydraulic cylinder 28.
A ring-shaped groove is provided on the outer periphery of the internal gear 18, and a hole is provided in the yoke 27, and between the groove and the hole there is provided a ring-shaped groove having a shape shown in detail in FIG. 9. The blocks 29 are engaged so that the internal gear 18 can be slid from side to side by the swinging of the yoke 27.

In the state shown in FIGS. 7 and 8, the internal gear 18 is the gear 1.
Since the shaft 13 and the shaft 16 are not engaged with each other, the shaft 13 and the shaft 16 are in a state where they can freely rotate with respect to each other, and perform the same function as the device shown in FIG.

However, if the internal gear 18 is moved to the right in FIG. 7 and the internal gear 18 is meshed with the gear 17 and also meshed with the gear 19, the rotations of the shafts 13° and 16 will be mutually constrained. .

In this case, the electric motors 7 and 8 can be used to the maximum, up to the total output of both, and can be used effectively.

Next, the third invention will be explained.

As can be seen from FIG. 4, when true speed rolling is performed, the torque applied to one work roll can reach several times the torque in conventional constant speed rolling.

Therefore, there is a limit to the transmission torque due to the strength of the drive shaft system, especially the spindle system.

The third invention is to reduce the torque of the drive shaft system, and one embodiment thereof will be explained with reference to FIG. 10.
4 through spindles 20, 21, respectively, and electric motors 22
．． 23 are connected to drive the backing rolls 3 and 4 as well.

In this case, the motors 7 and 8 are controlled in rotation speed so as to limit the circumferential speed of the work rolls 1 and 2, and the motors 22 and 23 are controlled in current so that the output of the motors 7 and 8 is constant. Let's do it.

In this case as well, power will be recovered.

The above rotation speed control, current control, and power recovery are controlled by the control device 24.

The present invention can significantly reduce the rolling force without changing the mechanism of the conventional rolling mill or the total capacity of the electric motor, thereby reducing the number of rolling passes, saving energy, reducing the amount of work roll wear, and improving the accuracy of rolled products. By driving the hold-up roll at the same time as the work roll, large torque can be transmitted, and as shown in Figure 4, the rolling torque can be increased, further increasing the rolling force reduction effect. It has the advantage of being possible.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the rolling state of a flat metal plate, Fig. 2 is a perspective view of the conventional equipment, Fig. 3 is a graph showing the rolling pressure distribution,
FIG. 4 is a graph showing rolling force and torque in the case of true speed rolling, FIG. 5 is a perspective view of an embodiment of the first invention, and FIG. 6 is a perspective view of an embodiment of the second invention. , FIG. 7 is an enlarged sectional view of the switching gear type speed tuning device in FIG. 6, FIG. 8 is an enlarged perspective view of the switching gear type speed tuning device in FIG. 6, and FIG. 9 is an enlarged view of the block in FIG. 8. 10 is a perspective view of one embodiment of the invention of FIG. 3; FIG. 1.2...Work roll, 3,4...Backup roll, 5.6...Spindle, 7,8,2
2, 23...Electric motor, 12...Switching gear type speed tuning device, 14゜15.17,19...
・Gear, 18...Internal gear.

Claims (1)

[Scope of Claims] 1. In a rolling mill that rolls a rolled material at true speed between two work rolls having different circumferential speeds, electric motors are individually connected to each of the two work rolls, and the two work rolls The capacity of the electric motor connected to the work roll with faster circumferential speed is larger than the capacity of the electric motor connected to the work roll with slower circumferential speed, and the capacity of the motor connected to the work roll with faster circumferential speed is The sum of the capacity of the electric motor connected to the roll and the capacity of the electric motor connected to the work roll with the slower circumferential speed is the same as the sum of the capacities of two electric motors of equal capacity in the case of a constant velocity rolling mill. A rolling mill drive device characterized by: 2. In a rolling mill that rolls a rolled material at true speed between two work rolls with different circumferential speeds, electric motors are individually connected to each of the two work rolls via spindles, and one of the two work rolls is The capacity of the electric motor connected to the work roll with a faster circumferential speed is made larger than the capacity of the electric motor connected to the work roll with a slower circumferential speed, and the electric motor is connected to the work roll with a faster circumferential speed. The sum of the capacities of the electric motor connected to the work roll with the lower circumferential speed and the capacity of the electric motor connected to the work roll with the lower circumferential speed is the same as the sum of the capacities of two electric motors of equal capacity in the case of a constant speed rolling mill, and A driving device for a rolling mill, characterized in that gears are attached to the spindles of the work rolls, and a speed synchronization device is provided in which the gears can be engaged and disengaged from each other. 3. In a rolling mill that rolls a rolled material at true speed between two work rolls with different circumferential speeds, an electric motor is connected to each of the two work rolls individually, and one of the two work rolls with a faster circumferential speed is used. The capacity of the electric motor connected to one of the work rolls is larger than the capacity of the electric motor connected to the work roll with a slower circumferential speed, and the electric motor connected to the work roll with a faster circumferential speed is used. and the capacity of the electric motor connected to the work roll with the slower circumferential speed are set to be the same as the sum of the capacities of two electric motors of equal capacity in the case of a constant speed rolling mill, and the capacity of the two work rolls is 1. A driving device for a rolling mill, characterized in that an electric motor is connected to each of the retainer rolls and to apply additional torque to the retainer rolls.