JPH0450965Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a roll coolant supply device for a rolling mill that can effectively control the thermal crown of a work roll to prevent a decrease in flatness due to local elongation of a rolled material.

BACKGROUND ART In recent years, in the rolling of plate materials, there have been increasingly strict requirements for product precision in the shape of the plate materials, and in particular, there has been a great demand for improvement in the shape of the plate materials, especially the flatness. Analysis of rolling phenomena has shown that flatness is affected by the behavior of the thermal crown of the work roll caused by the plastic working heat generated during rolling. Therefore, various means have been developed to control the thermal crown of the work roll. A method of controlling rolling oil (roll coolant oil) for work rolls in the axial direction of the barrel is widely used.

By the way, as a roll coolant supply device of this type, there has been one shown in FIG. 1 in the past. In the figure, 1 and 1 are work rolls of a cold rolling mill, 2 and 2 are back-up rolls, and 3n and 3n are coolant oil injection nozzle rows. As shown in FIG. 2, the coolant oil injection nozzle array 3n is arranged on the inlet side of the cold rolling mill at predetermined intervals in the axial direction of the barrel, with the injection ports facing the work roll 1.
It consists of a plurality of coolant oil injection nozzles 3, 3, which take charge of a predetermined width Z in the barrel axial direction of the work roll 1 as a cooling zone, and each of these has an individual pipe 4, which is equipped with a control valve 5, and a main body, which is equipped with a pump 6. It is connected to a coolant oil circulation tank 8 through a pipe 7. The coolant oil C in the coolant oil circulation tank 8 is an emulsion type coolant oil in which lubricating oil is mixed with water. 9 is a water collection stand, 10 is a water supply pipe, and 11 is a lubricating oil supply pipe. Reference numeral 20 denotes a coolant oil supply control device, which receives the output of a shape detector 30 that detects the shape of the rolled material S in the width direction and outputs shape parameters (signals), and detects the shape parameters at the predetermined interval position x in the width direction. and the target shape parameter, and sends a valve opening signal to the control valve 5 of the coolant oil injection nozzle 3 corresponding to the position at a predetermined interval in the width direction where the difference Δε(x) is 0. do.

The local difference Δε(x) between the shape parameter and the target parameter is caused by the unevenness of the friction coefficient in the barrel axial direction due to the thermal crown generated on the work roll 1. However, according to the above device, the work roll 1
Since more coolant oil C is injected to the part where the thermal crown occurs, the thermal crown is reduced and the flatness of the rolled material S is improved.

However, the coolant oil C used in conventional thermal crown control is a so-called emulsion-type coolant oil in which several percent of oil and fat are suspended in water, and as a result, the heat removal effect is not very good, and the coolant In order to prevent oil and fat from condensing and clogging in the pipes of the oil supply system, it is not possible to maintain the temperature at a low temperature, so the temperature difference between the work roll 1 and the work roll 1 is small because it is circulated at a temperature of approximately 60°C. There was a problem in that it was difficult to quickly reduce the thermal crown with conventional equipment that promoted a low heat removal effect and had only a coolant oil supply system.

This invention was made in view of this problem, and in addition to the coolant oil (lubricating oil) supply system, there is a By providing a cooling water supply system that supplies the cooling water that controls the thermal crown of the work roll more closely than the spacing between the lubricating oil injection nozzles, the lubricity between the work roll and the rolled material is ensured, and the cooling water To provide a roll coolant supply device which can greatly enhance the cooling effect of a work roll compared to the conventional one without causing rust due to rusting, and can further control the thermal crown of the roll.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 3, 40n is a cooling water injection nozzle row, which, as shown in FIG. As shown enlarged in FIG. 5, each cooling water injection nozzle 40 is
The injection port is directed toward the lower work roll 1 and lowered toward the back-up roll 2 side, and is disposed below the work roll center line parallel to the pass line on the exit side of the rolling mill. And cooling water injection nozzles 40, 40
... are connected to a main pipe 43 communicating with a cooling water source 42 via pipes 41, 41, respectively, and have a predetermined width z (<Z) in the barrel axial direction of the lower work roll 1.
serves as a cooling zone. In addition, each pipe 41
A control valve 44 is interposed therein. Each control valve 44
, valve open/close signals are individually given from the cooling water supply pattern control device 50. Reference numeral 45 denotes a water shielding plate, which has a brush-like draining portion 45a, and is disposed between the cooling water injection nozzle 40n and the pass line with the draining portion 45a in contact with the lower work roll 1.

The cooling water supply pattern control device 50 receives the local difference Δε(x) (signal) between the shape parameter and the target parameter from the coolant oil supply control device 20, and controls the predetermined widthwise direction where the difference Δε(x)>k. Control valve 4 of cooling water injection nozzle 40 corresponding to the interval position
Give a valve opening signal to 4. Here, k is the output h of the liquid level gauge 60 installed in the coolant oil circulation tank 8.
Based on, the total amount of cooling water W to be injected Σq (q:
The injection amount of the cooling water injection nozzle 40) is determined so as not to exceed the allowable cooling water supply amount Q(t). This allowable supply amount Q(t) of cooling water corresponds to the amount of coolant oil C that escapes by evaporating, scattering, or adhering to the rolled material.

In this configuration, cooling water W is further injected into the thermal crown generating portion of the lower work roll 1 that receives the coolant oil C. In this embodiment, as shown in FIG. 4, this cooling water injection area is not the same as the coolant oil injection area, but it is designed so that it can always cover the maximum part of each thermal crown occurrence area and has a very small area. To make it correspond to the area,
It is divided into smaller areas (z<Z) than the coolant oil injection area.

Even if the cooling water W has the same temperature as the coolant oil C, its heat removal effect is considerably greater than that of the coolant oil C. Therefore, if water at room temperature is used as the cooling water W, the cooling effect is higher than that of the coolant oil C. However, by using the cooling water (industrial water) itself at room temperature, its ability to control the thermal crown becomes extremely large. The temperature of the rolled material decreases rapidly, and the flatness of the rolled material in the width direction is promptly improved.

In this embodiment, the cooling water W is supplied to the lower work roll 1.
Since the cooling water W is sprayed toward the lower half of the roll, there is no fear that the cooling water W will adhere to the rolled material S via the work roll 1. Furthermore, in this embodiment, since the water shielding plate 45 is provided, Since the droplets of the cooling water W injected to the side work rolls 1 can be prevented from adhering to the rolled material S, it is possible to reliably prevent rust from forming on the rolled material S due to the cooling water W.

In addition, the temperature rise due to rolling of the work roll 1 reaches its maximum temperature on the exit side and decreases as it approaches the entry side. The thermal crown can be effectively controlled by controlling the cooling position.

Further, by setting the relationship between the spray widths of the cooling water injection nozzle 40 and the coolant oil injection nozzle 3 as Z>z, the thermal crown can be precisely controlled.

In this embodiment, the opening and closing of the control valves 5 and 44 are controlled to automatically control the supply pattern of the coolant oil C and the cooling water W in the barrel axial direction, but the application of the present invention is for this type of control. It is not limited to those having the following.

As described above, according to the present invention, in addition to the supply system of coolant oil (lubricating oil), cooling water is supplied to the lubricating oil below the center line parallel to the pass line of the lower work roll on the exit side of the rolling mill. By installing a cooling water supply system that supplies water more closely than the spacing between the injection nozzles, it provides the necessary lubrication between the work roll and the rolled material, while greatly increasing the cooling effect of the work roll compared to conventional methods. The thermal crown can be finely controlled, and there is no need to worry about rusting of the rolled material due to cooling water.
The above effects can be obtained.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the supply system flow and control part of a conventional roll coolant supply device, Fig. 2 is a plan view of the roll coolant oil injection nozzle array in the above conventional example, and Fig. 3 is a roll coolant supply device according to the present invention. FIG. 4 is a plan view of the cooling water injection nozzle array in the above embodiment, and FIG. 5 is an enlarged view of the main parts of the above embodiment. 1... Work roll, 3... Coolant oil injection nozzle, 3n... Coolant oil injection nozzle row (lubricating oil supply system), 4... Piping, 5... Control valve, 7
...Main piping, 8...Coolant oil circulation tank, 2
0...Coolant oil supply control device, 30...Shape detector, 40...Cooling water injection nozzle, 40n...
Cooling water injection nozzle row (cooling water supply system), 41...
...Piping, 42...Cooling water source, 43...Main piping, 4
4... Control valve, 45... Water shielding plate, 50... Cooling water supply pattern control device, 60... Liquid level gauge.

Claims (1)

[Claim for Utility Model Registration] On the entry side of the rolling mill, lubricating oil such as neat oil, palm oil, or emulsion type coolant oil is injected onto the work rolls and/or the rolled material in the direction of the barrel axis of the upper and lower work rolls. A lubricating oil supply system is provided in which a plurality of injection nozzles are arranged at predetermined intervals. . A roll coolant supply device, comprising: a cooling water supply system that supplies cooling water for controlling a thermal crown of a work roll more densely than the spacing between the injection nozzles.