JPS6119323B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rolling mill, and more particularly to a roll leveling device for a rolling mill.

First, a rolling mill having a roll leveling device according to the prior art will be described with reference to FIG. That is, a pair of upper and lower work rolls 1 and 2 for rolling the rolled material, roll jocks 3 and 4 of the work rolls 1 and 2, and upper and lower reinforcing rolls 5 for supporting the rolling load acting on each of the work rolls 1 and 2. 6, its jocks 7, 8, rolling rams 11, 12 and cylinders 13, which are provided on the operating side and the driving side, respectively, for positioning the lower work roll 2 and generating rolling load.
The mechanical system is constituted by a reduction jack having 14 and roll housings 9 and 10 that guide the upper work roll 1 and support the rolling load.

The electric and hydraulic systems include a control valve 17 for controlling the amount of oil in the reduction jack, and a ram 1.
Displacement meter 1 that detects and returns positions 1 and 12, respectively.
5, 16 and an operating side reduction setting device 22 and a driving side reduction setting device 2 for commanding the positions of the rams 11, 12.
3, a simultaneous reduction setting device 24 for simultaneously operating these setting devices 22 and 23, and a control device 18 for amplifying the difference between the setting signal and the ram displacement. In addition, in the figure, the symbols 19, 20, 2
1 indicates a pump port, a cylinder port, and a tank port, respectively.

Next, its operation will be explained.

When the rams 11 and 12 are in the lower position due to roll change etc., the simultaneous reduction setting device 24
For example, a positive command is added, and a command is applied from the control device 18 to the flow rate control valve 17 according to the difference between the command value and the outputs of the ram displacement meters 15 and 16. Therefore,
Oil flows into the compression jack from the pump port 19, causing the rams 11 and 12 to rise, and the value is measured by the displacement gauge 1.
5 and 16 for feedback. In this case, the pressure inside the jack is between the chock 7 of the upper reinforcing roll 5 and the housing 9 or 10, the upper working roll 1 and the upper reinforcing roll 5, the upper working roll 1 and the lower working roll 2, the lower working roll 2 and the lower reinforcing roll. 6. When all the gaps between the chock 8 of the lower reinforcing roll 6 and the ram 11 or 12 become zero, that is, when the rolls come into contact, the temperature rises rapidly. Here, due to movement or meandering of the rolled material in the strip width direction during rolling, reduction of variation in strip thickness distribution in the width direction, etc., the upper work roll 1 and the lower work roll A so-called leveling operation is performed so that the axes of the upper and lower work rolls 1 and 2 are parallel to each other, or so that the centers of the upper and lower work rolls 1 and 2 are at symmetrical positions at each point in the longitudinal direction of the roll surface along the pass line through which the rolled material passes. For this,
It is necessary to make fine adjustments to the rams 11 and 12 on the operating side and the driving side, respectively, independently. For this purpose, load setters 22 and 23 are provided on the operating side A and the driving side B, respectively.

The above operations will be described in more detail with reference to FIGS. 2 and 3.

In FIG. 2, a state (#1) in which the leveling of the lower work roll 2 is insufficient and it is not in contact with the upper work roll 1 is shown by a broken line, and a state in which the lower work roll 2 has been leveled and the upper work roll 1 (#2) is shown by a solid line.

When operated by the simultaneous reduction setting device 24, if the operation side of the lower work roll 2 and the drive side are poorly leveled as shown by the broken line, rolling oil is supplied from one side of the roll as shown in FIG. Spray the
While observing the amount of oil seeping out from between the upper and lower work rolls on the other side, adjust the operating side reduction setting device 2.
2 and the drive side reduction setting device 23, the lower work roll 2 is adjusted as shown by the solid line in FIG.

The conventional rolling mill as described above has the following drawbacks.

(1) In order to shorten the roll rise time using the simultaneous reduction setting device, the speed is increased to several tens of millimeters per minute or more, but in that case, the hydraulic pressure of the jack increases rapidly after each roll makes contact, causing roll flaws. and abnormal pressure increase occurs. Therefore, the operator must reduce the speed just before the rolls make contact to prevent scratches.

(2) Since the rolls contact each other in an inclined state, the occurrence of scratches is promoted.

(3) Since visual inspection and manual adjustment by the operator is required, the adjustment time becomes long and the adjustment accuracy decreases, making automation difficult.

SUMMARY OF THE INVENTION The object of the present invention is to eliminate the above-mentioned drawbacks and to provide a rolling device that can level the rolls easily and accurately.

A rolling mill characterized by the present invention includes a pair of work rolls for rolling a rolled material, a jack provided on a drive side and an operation side of a roll housing, respectively, for raising and lowering the work rolls, and a jack for raising and lowering the work rolls. Control valves provided for adjusting the pressure of the jacks, a signal control valve from a displacement meter that detects the displacement of both jacks, a fixed pressure reduction hydraulic circuit that performs fixed pressure reduction, and the work roll in a desired state. It includes a load setting device for setting the jack pressure to be brought into contact, and a load detection device for detecting the output loads of the two jacks, respectively, and the control valves are operated respectively by the load signals from the two load detection devices. The fixed pressure reduction hydraulic circuit is configured to adjust the pressure of the jack to the pressure set by each of the load setting devices, and the fixed pressure reduction hydraulic circuit and the fixed position reduction hydraulic circuit are selectively operated. According to
This allows leveling work to be performed easily and precisely.

Next, a preferred embodiment of the rolling mill according to the present invention will be described with reference to FIG.

In FIG. 4, the same reference numerals as those shown in FIG. 1 indicate the same or equivalent parts or devices, so detailed explanation thereof will be omitted in the following description.

The rolling apparatus shown in FIG. 4 is different from the one shown in FIG.
A control device 25 is provided which receives signals from these detectors 33 and 34 via the switch 32 and controls the control valve 17 based on the signals. Further, a drive side load setter 26 and an operation side load setter 27 are provided on the drive side and the operation side, respectively, on the switch 2.
9 and 30, and these constitute a constant pressure pressure reduction hydraulic circuit.

Furthermore, via the switch 28, the simultaneous pressure setting device 2
4 is provided.

The switches 28 and 32 are switches that are switched according to the load of the reduction jack, and in this embodiment, they are switched when the outputs of the load detectors 33 and 34 reach a preset value. There is.

Next, the operation of this rolling apparatus will be explained.

First, in the initial state, the rams 11 and 12 are in the lower position, and the loads on the load detectors 33 and 34 are below the set values, so the switches 28 and 31 are closed.
Switches 29, 30, and 32 are each opened.

The command from the simultaneous reduction setting device 24 and the ram 1
The difference between the actual positions of 1 and 12 is the displacement meter 15,
16 and amplified by the controller 18 to drive the control valve 17 to raise the rams 11 and 12 simultaneously. At that time, when the work rolls come into contact and the pressure inside the jack increases, this pressure increase is detected by the load detectors 33 and 34, respectively, and when the detected value exceeds the set value, the switches 28 and 31 are opened. With this, the movement of the rams 11 and 12 due to the fixed position pressure ends,
The upward movement of the rams 11, 12 is stopped. At the same time, the switches 29, 30, and 32 are closed, and the positional pressure is switched to the positional pressure. That is, the pressures in the jacks on the operation side A and drive side B rise to the pressures set by the load setting devices 26 and 27, respectively. The setting values of the setters 26 and 27 are determined according to the specifications of the rolling mill, but may be the pressure at the time of switching the positional reduction described above. In this way, the leveling adjustment of the upper and lower work rolls 1 and 2 is performed, and it is also effective to forcibly create a difference in the pressure on the operation side and the drive side based on the difference in characteristics of the rolling mill. In order to further increase such adjustment effect, a roll bender can also be added at this time. Load detector 3
The detected values 3 and 34 are respectively detected by the load setter 26,
27, a leveling adjustment end signal is issued on the condition that the two match, and this end signal opens switches 29, 30, and 32, and closes switch 31. , returns to stereotaxic pressure from the stereotaxic pressure.

Then, the gap between the work rolls 1 and 2 is reset and rolling is performed. These operations will be explained with reference to FIGS. 5 to 7.

FIG. 5 shows the relationship between the position of the ram, the pressure inside the jack, and time when the ram is raised at high speed under fixed pressure according to the prior art. That is,
As soon as the rolls make contact, the pressure inside the jack rises rapidly, causing scratches and abnormal pressure rise.

FIG. 6 shows the relationship between the jack internal pressure, the ram position, and time in a conventional method for preventing the above-mentioned damage and abnormal pressure increase.
That is, the case is shown in which the speed is decelerated immediately before roll contact, and the jacking pressure is adjusted by increasing or decreasing the leveling pressure.

FIG. 7 shows an example of a rolling machine using the device of the present invention, in which the switching pressure from fixed position reduction to constant pressure reduction is set to a value slightly higher than the pressure at the time of roll contact, and when this pressure is reached, constant pressure reduction occurs. Although the model example shows the case where the pressure is returned to the fixed position pressure after leveling is completed, in reality, these operations are completed instantaneously.

As described above, the rolling apparatus according to the present invention can accurately and easily adjust the leveling of the rolls while preventing roll scratches and abnormal pressure increase.
This allows complete automation of the rolling operation.

In the above embodiment, the load detectors 33 and 34 are used as a means for detecting roll contact, but these detectors can be used to directly or indirectly receive the jacking output using a load cell installed at the top or bottom of the mill. A substance that can be detected visually can be used.

Furthermore, in the above embodiment, it is explained that the positional pressure is applied until the rolls come into contact, then the constant pressure reduction is performed, and then the transition is made to the positional pressure reduction.
raising the ram to roll contact by means of a fixed or variable shut-off valve and a roughly pressure-controlled hydraulic source;
Thereafter, it is also possible to level the pressure by shifting from the fixed pressure to the constant pressure, or directly to the constant pressure, and then to shift to the fixed pressure. That is, the leveling work can also be performed by combining constant pressure reduction and fixed pressure reduction using a flow rate control valve.

In addition, in the above embodiment, constant pressure is also achieved with the flow rate control valve 17 (generally a servo valve is used), but this is of course possible even if a pressure control valve is installed It is possible to fully achieve the purpose.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a rolling machine according to the prior art, FIG. 2 is an enlarged view showing the contact state of work rolls, and FIG. 3 is a schematic side view of the rolling mill showing a method of inspecting the contact state of work rolls according to the prior art. Fig. 4 is a block diagram of a rolling mill according to the present invention, Fig. 5 is a graph showing the relationship between jacking pressure and ram position and elapsed time when leveling work is not performed, and Fig. 6 is a graph showing the relationship between leveling work and elapsed time according to the prior art. FIG. 7 is a graph showing the relationship between the jacking pressure, the ram position, and the elapsed time in the rolling mill according to the present invention. 1, 2... Work roll, 5, 6... Reinforcement roll, 11, 12... Ram, 13, 14... Cylinder, 15, 16... Displacement meter, 17... Control valve, 1
8... Control device, 22, 23... Pressure setting device, 2
4...Simultaneous pressure setting device, 25...Control device, 2
6, 27...Load setting device, 33, 34...Load detector.

Claims (1)

[Claims] 1. A pair of work rolls for rolling the rolled material, a jack provided on the drive side and an operation side of the roll housing for raising and lowering the work roll, and for adjusting the pressure of both the jacks. The work roll is brought into contact in a desired state with a control valve provided respectively, a displacement meter that detects the displacement of the two jacks, and a fixed pressure reduction hydraulic circuit that performs fixed pressure reduction by feeding back the output of the displacement meter to the control valve. It includes a load setting device that sets the jack pressure, and a load detection device that detects the output load of each of the jacks, and the pressure of each jack is adjusted by operating the control valves based on the load signals from the two load detection devices. a hydraulic circuit for constant pressure reduction to adjust the pressure to the pressure set by each of the load setting devices; A rolling mill characterized by being provided with circuit switching means for controlling both jacks.