JPS60206513A - Automatic sheet thickness control device - Google Patents

Abstract

PURPOSE:To prevent the lowering of the yield and productivity of a product by providing a load upper-limit-signal outputtting means and a target sheet-thicknes correcting means and continuing rolling even when a rolling load reaches its upper limit. CONSTITUTION:An automatic sheet-thickness control device consist of a load upper-limit-signal outputting means, which outputs a load upper-limit signal when a rolling load reaches a set upper-limit value, and a target sheet-thickness correcting means. Said target sheet-thickness correcting means reduces gradually the target sheet thickness in the decereasing direction of rolling load without stopping the rolling even when a load upper-limit signal is outputted. A rolling material is fed to a rolling mill provied with said control device for loading the mill, then the material is controlled to the target sheet thickness.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention involves passing a rolled material through a rolling mill to apply a rolling load,
The present invention relates to an automatic plate thickness control device that controls rolled material to a target plate 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 between the rolling rolls is rapidly opened to protect the rolling mill, especially in rolling mills equipped with hydraulic reduction devices. and has stopped working. However, some rolling materials are rolled near the upper limit of the rolling load II), and a slight increase in the rolling load causes the upper limit to be exceeded, leading to a situation in which rolling is 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. I am going to do something.

[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 reduced to a predetermined value in the direction of decreasing the rolling load without stopping rolling. It is something to do.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 1 and FIG.

In FIG. 1, the material to be rolled is rolled in the process of passing through the gap between the upper and lower rolls of a rolling mill.

Setting the gap between the upper and lower rolls of the rolling mill is mainly performed by the electric rolling down device 3 during initial setting, that is, setting before rolling, and during rolling, it is performed by the hydraulic rolling down device 3 in accordance with the output ΔB of the automatic plate thickness control device j. Automatic plate thickness control device! is the gap SM caused by electric rolling down from the electric rolling down device 3,
The gap SH caused by the hydraulic reduction is inputted from the hydraulic reduction device, and the rolling load P is input from the rolling load detector t, respectively, and the output ΔS is sent to the hydraulic reduction device HI as an operation signal, as described above.

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

Gap S between the upper and lower rolls of the rolling mill. is expressed as the sum of the gap sH due to hydraulic pressure reduction and the ear sM due to electric pressure reduction, so 8. +SM . . . ++ (1) This addition is performed by an adder //. On the other hand, the Mill constant is M (generally TO
(expressed in the unit n/a), the elongation of the mill can be calculated from the rolling load P and the mill constant V as p/M. This operation is performed by a divider. The elongation p/M of the mill determined here is adjusted by adjusting gain 8.
Multiply the mill elongation S t to be considered in the gauge meter plate thickness.
・Add P/M.

Since the gauge meter plate thickness h8 is calculated as hg-so+s, -P/M, this calculation is performed by the adder llI using the outputs of the adder 1/ and the adjuster 13 described above.

Contact A is a contact 17 that opens for a short time after a predetermined period of time after the rolled material is caught in the rolling mill. Via this contact A, the gauge meter plate thickness at that time is input to the lock-on circuit 15. This lock-on value hgL, which is locked on as the gauge meter plate thickness lock-on value hg1, and a plate thickness correction value ΔhgL from the load limiting control device IO, which will be described later, are added by an adder 16. The plate thickness correction value Δh g L is normally zero.

Next, the comparator/7 calculates the deviation between the gauge meter plate thickness hg from the adder/4() and (h6L-Δh6L) from the adder 16, and calculates the gauge meter plate thickness deviation Δh.

That is, Δhg=hg-(h8I, +15g L)...
- (3).

This gauge meter plate thickness deviation Δh is calculated using the plate thickness control adjuster ig.
is input and multiplied by the plate thickness control gain (proportional integral gain), which is then output as the output ΔS of the automatic plate thickness control device j via contact B.
shall be. Contact B is a contact that opens and closes from the lock-on timing, that is, the closing 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 load P exceeds the preset upper limit value PTII when the rolling material is rolled near the upper limit value of the rolling load, the load limit adjuster /9 is activated. Detect this and close contact C. By closing this contact O, 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 X to the integrator 2/. This rate signal is a signal representing the amount of change in the gauge meter plate thickness lock-on value per unit time. Therefore integrator 2
1 outputs a signal that increases at a constant rate with time as the target plate thickness correction amount Δht from the load limit control device 10.

This target plate thickness correction amount Δh L is determined by the comparator (3
) As is clear from the equation, it acts to reduce the gauge meter plate thickness, that is, the target plate thickness at that time. Output ΔS
This decrease acts in the direction of opening the upper and lower roll gear roughs of the rolling mill λ, and the rolling load P decreases.

The rolling load P decreases and the rolling load P reaches the upper limit” U TJ
When the value p'ty L is lowered by a certain value, the load limit regulator 19 detects this and opens the contact C.

This changes the gauge meter board thickness lock-on value, cuts off the input from the output circuit to the integrator 21, and integrator 2
The output of / is kept constant thereafter.

When there is no more rolling material in the rolling mill λ, the contact closes, and the integrator Ll is reset by the reset signal from the reset circuit 2, returning to the original normal operating state. [Effects of the invention] As described above, according to the present invention, continuous rolling is possible even near the upper limit of the rolling load (1), and rolling is not stopped even if the rolling load exceeds the upper limit, so that the product yield and rolling Improved productivity can be achieved.

[Brief explanation of the drawing]

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. C...Rolling material, λ...Rolling machine, 3...Electric rolling device, ≠...Hydraulic rolling device, j...Automatic plate thickness control device,
t...Rolling load detector, P...Rolling load, h...
・Gauge meter plate thickness, SL (...Earth between upper and lower rolls by hydraulic pressure reduction, SM...Gap between upper and lower rolls by electric pressure reduction, 10...Load limit control device, /U...
・Divider, 13...Mil elongation adjuster, /! f...Gougenota board thickness lock-on circuit, 1g...board thickness control adjuster, /? ... Load limit adjuster, ... Gauge meter plate thickness lock-on value change rate output circuit, ... Integrator. Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] In an automatic plate thickness control device that passes a rolled material through a rolling mill and applies a rolling load to control the rolled material to a target thickness, the load is applied when the rolling load reaches a preset upper limit. A load upper limit signal transmitting means for outputting an upper limit signal; and a target plate thickness that gradually reduces the target plate thickness to a predetermined value in a direction in which the rolling load is reduced without stopping rolling when the load upper limit signal is transmitted. An automatic plate thickness control device characterized by comprising a correction means.