JPH0471607B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an automatic sheet thickness control device that applies a rolling load to a rolled material through a rolling mill and controls the rolled material to a target thickness.

[Technical background of the invention and its problems]

If the rolling load exceeds a preset upper limit during rolling operation by a rolling mill, the gap of the rolling rolls is opened rapidly to protect the rolling mill, especially in rolling mills equipped with hydraulic reduction devices. and has stopped working. However, some rolling materials may be rolled near the upper limit of the rolling load (for example, when hard materials or materials with low temperatures are rolled), and a slight increase in the rolling load may cause the upper limit to be lowered. The value will be exceeded, leading to a situation where rolling will be stopped. Once the rolling operation is interrupted,
Subsequent processing takes time and productivity is significantly reduced.

[Purpose of the invention]

An object of the present invention is to provide an automatic plate thickness control device that allows rolling to continue even when the rolling load exceeds a preset upper limit, thereby preventing a decline in product yield and productivity. be.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized in that when the rolling load reaches a preset upper limit, the target plate thickness is gradually increased to a predetermined value in the direction of decreasing the rolling load without stopping rolling. It is something to do.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, a rolling material 1 is rolled in the process of being passed through a gap between upper and lower rolls of a rolling mill 2. As shown in FIG. Gap setting between the upper and lower rolls of the rolling mill 2 is mainly performed by the electric rolling down device 3 during initial setting, that is, setting before rolling, and is performed by the hydraulic rolling down device 4 during rolling according to the output ΔS of the automatic plate thickness control device 5. It will be done. The automatic board thickness control device 5 is an electric rolling down device 3
The gap S _M caused by the electric reduction is taken in from the hydraulic reduction device 4, the gap S _H caused by the hydraulic reduction from the hydraulic reduction device 4, and the rolling load P from the rolling load detector 6 are taken in as input signals, and as mentioned above, the output ΔS is sent to the hydraulic reduction device 4. is sent as an operation signal.

FIG. 2 shows the internal configuration of the automatic plate thickness control device 5. As shown in FIG.

The gap S _O between the upper and lower rolls of rolling mill 2 is the gap S _{H caused by hydraulic rolling and the gap S H} caused by electric rolling.
Since it is expressed as the sum with S _M , S _O =S _H +S _M (1) This addition is performed by the adder 11. On the other hand, the Mill constant is M (generally expressed in units of Ton/mm)
Then, the elongation of the mill is the rolling load P and the mill constant M
It can be found from P/M. This operation is performed by divider 1
It is done in 2. Mill elongation P/
Multiply M by the adjustment gain S _f using the adjuster 13 to find the elongation S _f P/M of the mill to be taken into account in the gauge meter plate thickness.

The gauge meter plate thickness h _g is obtained by h _g = S _O + S _f · P/M (2), so this calculation is performed by the adder 14 using the outputs of the adder 11 and adjuster 13 described above. conduct.

Contact A is a contact that closes for a short time after a predetermined period of time after the rolling material is bitten by the rolling mill.
The current dirge meter plate thickness h _g is input to the lock-on circuit 15 via the gauge meter plate thickness lock-on value h _gL . An adder 16 adds this lock-on value h _gL and a plate thickness correction value Δh _gL from a load limiting control device 10, which will be described later.
The plate thickness correction value Δh _gL is normally zero.

Next, the comparator 17 calculates the gauge meter plate thickness h _g from the adder 14 and (h _gL +Δh _g
Calculate the deviation from L) to find the gauge meter plate thickness deviation Δh _g . That is, Δh _g = h _g − (h _gL + Δh _gL ) ...(3).

This gauge meter plate thickness deviation Δh _g is input to the plate thickness control adjuster 18, and the product multiplied by the plate thickness control gain (proportional integral gain) is set as the output ΔS of the automatic plate thickness control device 5 via contact B. . Contact B is a contact that opens and closes from the lock-on timing, that is, the opening timing of contact A until the rolled material passes through the rolling mill.

In the above-mentioned load limit control device 10, when the rolling material is rolled near the upper limit value of the rolling load, the rolling load P is set to the upper limit value P _UL set in advance.
If it exceeds, the load limit regulator 19 detects it,
Close contact C. By closing this contact C, a gauge meter plate thickness lock-on value change rate signal K is input from the gauge meter plate thickness lock-on value change rate output circuit 20 to the integrator 21. This rate signal K is a signal representing the amount of change in the lock-on value of the gauge meter plate thickness per unit time. Therefore, the integrator 21 outputs a signal that increases at a constant rate with time as the target plate thickness correction amount Δh _g L from the load limit control device 10.

This target plate thickness correction amount Δh _g L acts on the comparator 17 to increase the gauge make plate thickness, that is, the target plate thickness at that time, as is clear from equation (3). The decrease in the output ΔS acts in the direction of opening the upper and lower roll gaps of the rolling mill 2, and the rolling load P decreases. Rolling load P decreases and rolling load P reaches its upper limit.
When the load becomes less than a value P' _UL which is smaller than P _UL by a certain value, the load limit regulator 19 detects this and opens the contact C. As a result, the input from the gauge meter plate thickness lock-on value change rate output circuit 20 to the integrator 21 is cut off, and the output of the integrator 21 is kept constant thereafter.

When the rolling mill 2 runs out of rolling material, the contact D closes, and the integrator 21 is reset by a reset signal from the reset circuit 22, returning to the original normal operating state.

〔Effect of the invention〕

As described above, according to the present invention, continuous rolling is possible even near the upper limit of the rolling load, and rolling is not stopped even if the rolling load exceeds the upper limit, thereby improving product yield and rolling production. It is possible to achieve improvement in sexual performance.

[Brief explanation of drawings]

FIG. 1 is a layout diagram of a rolling mill equipped with an automatic plate thickness control device of the present invention, and FIG. 2 is a block diagram showing an embodiment of the automatic plate thickness control device in FIG. 1...Rolling material, 2...Rolling machine, 3...Electric rolling device, 4...Hydraulic rolling device, 5...Automatic plate thickness control device, 6...Rolling load detector, P...Rolling load, h _g ... Gauge meter plate thickness, S _H ... Gap between upper and lower rolls by hydraulic reduction, S _M ... Gap between upper and lower rolls by electric reduction, 10... Load limit control device, 12... Divider, 13... Mill elongation adjuster, 15...gauge meter plate thickness lock-on circuit,
18... Plate thickness control regulator, 19... Load limit regulator, 20... Gauge meter plate thickness lock-on value change rate output circuit, 21... Integrator.

[Claims]

1. In a mandrel mill rolling device equipped with a pair of grooved rolls, a hydraulic reduction cylinder that moves the grooved rolls toward and away from a pipe, and a servo valve that sends pressure oil to the hydraulic reduction cylinder, rolling a load detector that detects the load; a first calculator that calculates the amount of elongation of the mill by dividing the rolling load during rolling continuously detected by the load detector by a mill constant; a second computing unit that calculates the reduction amount of the pair of hole-shaped rolls by adding the elongation amount of the mill to the reduction setting value of the roll gap; and a displacement detector that detects the amount of movement of the piston of the hydraulic reduction cylinder; The present invention is characterized in that a comparison calculator is provided which determines a deviation between the amount of movement of the piston from the displacement detector and the amount of narrowing of the hole-shaped roll from the second calculator, and provides the deviation to the servo valve. mandre

Claims (1)

An automatic plate thickness control device comprising: a positive amount calculation means; and a roll gap control means for controlling the gap between the upper and lower rolls based on the amount of correction of the gap between the upper and lower rolls.