JPS60196202A - Control device for rolling at different peripheral speeds - Google Patents

Abstract

PURPOSE:To provide a titled device which controls effectively the ratio between different peripheral speeds of rolls by the constitution consisting in calculating the coefft. of friction between the rolls for rolling at different peripheral speeds and a material to be rolled, making the calculated coefft. coincident with the max. rolling torque determined from rolling pressure and rolling the material to be rolled. CONSTITUTION:A coefft. mu of friction is calculated by a function generator 2 from the roll speed detected by a roll speed detector 1 in a rolling mill which drives independently upper and lower rolls and performs rolling at different peripheral speeds. On the other hand, a rolling pressure P is detected by a pressure detector 3 and is multiplied by the above-mentioned mu. The result thereof is further multiplied by the radius R/2 of the roll and the theoretical max. rolling torque is calculated. On the other hand, the driving torque of the roll is detected by a torque detector 4 and is compared with the above-mentioned calculated theoretical max. rolling torque. The peripheral speed ratio is so controlled that the difference therebetween is made zero. Rolling is thus executed always at the max. ratio between the different peripheral speeds and the rolling at different peripheral speeds with the highest efficiency is made possible.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a different circumferential speed rolling control device that makes it possible to effectively control the different circumferential speed ratio in a metal rolling mill that performs different circumferential speed rolling. .

[Background of the invention]

Since different circumferential speed rolling has the effect of reducing rolling pressure,
It has advantages such as improving the shape of the rolled material, and there are increasing signs of its practical use in recent years.

Along with this, several control methods for rolling at different circumferential speeds have been proposed, but in practice none of them can effectively prevent slips between the rolls and the material to be rolled. At present, it has not been possible to realize effective rolling at different circumferential speeds. In other words, in order to prevent or suppress this slip, it is necessary that the point where the speeds of the rolled material and the roll match (neutral point) does not protrude from the contact range between the roll and the rolled material ( (See Figures 2 and 3) However, in the current method, the speed of the material to be rolled (hereinafter simply referred to as "rolling") is actually measured using contact rolls to determine whether or not it is at a speed that is likely to cause slipping. It was customary to determine the difference between different circumferential speeds and change the ratio of different circumferential speeds. However, detecting the extraction speed using this contact roll requires considerable equipment;
Due to the lubrication state of the punching surface and the influence of the moment of inertia of the roll, there has been a drawback that the detection accuracy is significantly degraded, especially during acceleration and deceleration. For this reason, in the conventional control method, it is necessary to carry out rolling by keeping the different circumferential speed ratio quite small in consideration of the protrusion of the neutral point.

[Purpose of the invention]

An object of the present invention is to provide a control method for rolling by making the drive torque of the rolls match the theoretical maximum torque determined by the rolling conditions (pressure, speed, etc.).

[Summary of the invention]

When the different circumferential speed ratio is increased from the state of uniform rolling, the roll drive torque on the high speed side increases, and conversely, the roll drive torque on the low speed side decreases, as shown in FIG.

At this time, as shown in FIGS. 2 to 4, the position of the neutral point approaches the exit of the rolled material on the high-speed roll side as the different circumferential speed ratio increases.

If the neutral point M goes outside beyond the exit of this rolled material, slipping occurs. Once slip occurs, the board cannot be used as a product. When the neutral point M coincides with the outlet of the rolled material, the theoretically maximum different speed ratio is achieved, and the roll drive torque T at this time is: 1"=--RXμxp (1) R: Roll diameter μ: Friction coefficient P: Rolling pressure Conversely, by matching the roll drive torque on the high-speed side to the torque calculated by equation (1), rolling with the maximum different speed ratio can be achieved. In formula (1), R is the roll diameter and is usually known, and P can be easily detected with high precision by a rolling pressure detector. Also, μ is mainly expressed as a function of the rolling speed, For example, the formula % formula % (2) for 51 m5 is known. Therefore, it is possible to calculate the roll drive torque using equation 1 (1). In practical use, the roll drive torque on the high speed side is Naturally, it is necessary to control so that the maximum metering capacity, which is determined visually or electrically, does not exceed 1-lux.

[Embodiments of the invention]

FIG. 5 shows an embodiment of the present invention. In the figure, a friction coefficient μ is calculated by a function generator 2 from the roll speed detected by a roll speed detection device 1. On the other hand, the rolling pressure P is detected by the pressure detector 3, the above-mentioned μ and multiplication are combined, and further,
The roll radius R/2 and the multiplier are combined to calculate the theoretical maximum rolling torque.

The drive torque of the roll is detected by the torque detector 4 and compared with the maximum rolling torque based on calculation theory, and if there is a difference, the different circumferential speed ratios are controlled so that the difference is set to zero. In this way, rolling can always be performed at the maximum different circumferential speed ratio. In reality, this rolling torque may be limited by mechanical and electrical conditions. Furthermore, the roll torque can be detected from the current I, voltage V, and speed W of the roll drive motor. It is possible to realize stable rolling with the maximum different speed ratio.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between different circumferential speed ratios and rolling torque, Figures 2 to 4 are diagrams showing the position of the neutral point during rolling at different circumferential speeds, and Figure 5 is a system diagram of an embodiment of the present invention. It is. Japanese grass 1 hard Japanese grass 5 hard

Claims (1)

[Claims] j. A metal rolling machine that includes a roll driving torque, a detection device, a rolling pressure detector, and a roll circumferential speed detector, and performs rolling at different circumferential speeds by independently driving upper and lower rolls. A means for calculating a friction coefficient between the roll and the rolled material determined by the rolling conditions, and a means for matching the roll driving torque on the high speed side to the maximum rolling torque calculated from the friction coefficient and the rolling pressure. A different circumferential speed rolling control device comprising means for controlling different circumferential speed ratios as follows.