JPS6188909A - Method of preventing collision between rolling rolls - Google Patents

Abstract

PURPOSE:To prevent the breakage of roll and to improve the accuracy of sheet thickness by computing a roll gap at the time when the tail end of a rolling stock runs out of rolls, based on the sheet thickness, the roll gap and the thermal expansion of roll, etc. and spreading the roll gap based on the computed value. CONSTITUTION:A roll-diam. prediction device 1 predicts the change of roll diam., due to the amount of thermal expansion of roll and its wear, etc. after its zero adjustment, by a prescribed equation, based on the sheet thickness of outlet side outputted from a sheet-thickness meter 15 and the roll gap from a rolling reduction device 8. When the tail end of a rolling stock 13 is detected by a stock-position detector 11, a computer 3 discriminates the roll contact at that time by using a roll-diam. prediction value 2 outputted from the device 1 and the roll gap of an automatic rolling-reduction-positioning device 5. When the spreading of roll gap is required, the computer spreads it by a required quantity. In this way, the roll breakage is surely prevented and the sheet- thickness accuracy is improved.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to thin plate rolling equipment, and predicts the roll gap during ash removal at a timing before the material being rolled ends up, and the upper and lower rolls If the roll gap is such that it would contact and be damaged, the roll gap is opened to the extent that the rolls do not come into contact during ash removal.

[Technical background of the invention and its problems]

Generally, when rolling a thin plate, as shown in Figure 1,
Since both the entry and exit thicknesses are small and a high rolling load is applied, the elongation of the mill is greater than the plate thickness, and the true roll gap becomes negative.

This is conventionally shown by the following equation.

S? = h --(2) 5R=88-△5(3) However, 8B: Roll gap indication value by roll-down position detector (wear) Pz: Load at zero adjustment (ton) Mz: Zero 0
．． 4: Mill constant (ton/凋) 11: Thickness
-) △S: Amount of thermal expansion of zero-adjustment roll (・hawk) (The time of expansion is assumed to be positive.) ST: Roll gap of X (theory of roll spacing (iffi (1=ll)) P: Load during rolling
(ton) M: Mill constant during rolling (t
oll/IQ) SR: Actual roll gear position tf (1
m). In FIG. 1, m is the plasticity coefficient, H is the entrance plate thickness, Sm is the elongation of the mill during rolling, and 5n10 is the elongation of the mill at zero adjustment.

For example, h==1. Q12 1 F=1500for++ M
- At the time of 500 tons, the true roll gap ST is 8 teeth = 1.0 = t. .

=-2,0CICM>, which is a negative value. Further, thermal expansion after zero adjustment, roll wear, etc., cause a change in roll diameter ΔS.

Because of this, a discrepancy occurs between the roll gap instruction value Ss and the actual gap position SRj, so that the true roll gap setting also does not reach the target value.

Since the roll diameter generally expands, ΔS is positive.

Therefore, the actual roll gap position S11 is 68 minutes smaller than the target value S8, and the true roll gap is also smaller.

When rolling is carried out under such conditions, the load P is no longer applied when the rolled material reaches its bottom, and the elongation V of the mill quickly becomes 0, so that the true roll gear S of the upper and lower rolling rolls becomes negative. Therefore, it will collide and be damaged.

Conventionally, in order to prevent this roll collision, if roll contact occurred before the material fell through, the roll gap was manually widened to prevent roll contact.

However, this conventional method has the disadvantage that, because the actual roll diameter is not known, it is sometimes unclear whether or not roll contact will actually occur during tail removal. Therefore, when manually widening the roll gap (I don't know how much to widen it, I end up widening it significantly,
There was an inconvenience that the accuracy of the plate thickness at the tail end of the material deteriorated significantly.

[Purpose of the invention]

The present invention has been made in order to eliminate the above-mentioned drawbacks, and when removing the bottom of the material, it is determined at a previous timing whether or not roll contact will occur, and it is determined that roll contact will occur. The purpose of the present invention is to provide a method for preventing roll collisions that can sometimes prevent roll contact by calculating the roll gap that prevents roll contact and widening the roll gap by that amount. shall be.

[Summary of the invention]

The present invention uses a computer to process the roll diameter predicted by a roll diameter prediction device, the roll gap instruction value from the rolling device and the positioning device, the rolling load, and the material position detection signal,
In the tail removal, the true roll gap is calculated, and if it is necessary to widen the roll gap to prevent roll contact, the automatic rolling down positioning device t1 is instructed to widen the roll gap so that the rolls do not come into contact.

[Embodiments of the invention]

(4th generation of implementation) An embodiment of the present invention will be described below with reference to the drawings. Second
The diagram shows the case in which the present invention is implemented! ,,e! It is a figure showing FFIJ formation.

While rolling the rolled material 13, the computer 3 tracks the rolled material 13 based on the outputs of the material position detection device 11 that detects the presence or absence of the rolled material 13 and the pulse transmitter 14 that detects the moving speed of the rolled material 13.

In addition, to ensure that the rolled material 13 has the target thickness, the calculator 3 inputs and calculates the current thickness from the thickness meter 15 and the load from the rolling load detection device 10, and then instructs the rolling automatic positioning device 51. give. On the other hand, the roll diameter prediction device 1 and the calculator 3 perform control to widen the roll gap to prevent roll contact.

In addition, the roll diameter prediction device 1 predicts the change in roll diameter ΔS due to thermal expansion fit after zero adjustment, roll wear, etc. using the following equation based on the exit side plate thickness from the plate thickness gauge 15 and the roll gap from the rolling down device 8.

However, hX: Plate thickness (plate thickness meter) ST: Direct roll gap (Mar) P: Rolling load (ton) M: Mill constant (toΩ/column) △S: Amount of change in roll diameter (Plate) be.

(Function of the Embodiment) When the tail end of the rolled material 13 is detected by the material level tFi detector 11C (for example, it may be a heat detector, a photo sensor, or a load relay signal from the front stand), the computer 3 Roll diameter prediction value 2 from roll diameter prediction device 1 and roll gap and load 6 from rolling down automatic positioning device 5
Use this to determine whether or not the rolls are in contact with each other.

If it is necessary to widen the roll gap so that the rolls do not touch, the pulse generator 14 tracks the rolled material 13, and the computer 3 widens the roll gap when the tail end reaches the point where the rolling device 8 can reach the end just in time. At this time, the rolling down device is controlled so that the roll gap is such that the rolls do not come into contact with each other. That is, the calculator 3 controls the rolling down device 8 to open the roll gap by the sum of the negative absolute value of the true roll gap and the amount of change in roll diameter due to roll expansion.
control. This will be explained specifically using the above-mentioned values.

The rolling mill indicator shows that the true roll gap is a negative value (-2,
0aR) and the thermal expansion amount of the roll is 0.5 mm, the rolling machine is rolled down until the rolling mill indicator indicates 0.5, that is, the roll gap is reduced to 2.5 m in total. Control device 8.

By doing this, the rolls sometimes do not come into contact with each other during tail removal, and damage to the rolls can be prevented.

Furthermore, deterioration in plate thickness accuracy can be minimized.

〔Effect of the invention〕

As explained above, according to the rolling roll collision prevention method of the present invention, it is possible to eliminate the occurrence of roll contact during bottom removal of the material, and therefore it is effective in preventing damage to the rolls. Furthermore, according to the present invention, it is possible to improve plate thickness accuracy since the roll gap is not widened too much as in manual operation.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the relationship among elongation of the mill, plastic deformation of the material, roll gap, and plate thickness, with plate thickness on the horizontal axis and load on the vertical axis. Fig. 2 shows the relationship between the elongation of the mill, plastic deformation of the material, roll gap, and plate thickness. FIG. 1... Roll diameter prediction device 2... Predicted roll diameter 3.
...Calculator 4...Material detection signal 5...Automatic positioning device for rolling down 6...Positioning signal 7...Down position signal 8...
- Rolling down device 9... Material position signal 10... Rolling load detection device 11... Material detection device 12... Roll roll 13
...Rolled material 14...Pulse transmitter 15.
...Plate thickness gauge 16...Plate thickness signal (7317)
Representative Patent Attorney Noriyoshi Noriyuki (and 1 other person) No.
1 Figure, ,-,,H

Claims (1)

[Claims] In a rolling mill control device that rolls rolled material to a predetermined thickness from the tip to the tail end, the plate thickness, current roll gap, rolling load, and rolling information are measured from a plate thickness gauge installed on the exit side of the rolling mill. The roll gap when the tail end of the rolled material passes through the rolling mill is calculated from the accompanying thermal expansion of the rolls, and the calculation result shows that if a kiss roll occurs during tail end removal, the roll gap should be adjusted to an extent that the rolls do not collide. A rolling roll collision prevention method characterized by widening the rolls.