JPS6224820A - Method for controlling coil car roll of down coiler - Google Patents

Abstract

PURPOSE:To prevent rubbing flaws and loosening by the slack winding of a coil by the constitution consisting in automatically pressing coil car rolls to the coil before the tail end of a strip passes through pinch rolls. CONSTITUTION:The tail end of the trip S is detected by a detector 6 installed on the upper stream side of the pinch rolls 3. The position of the predicted coil outside diameter when the tail end of the strip passes through the rolls 3 is determined by calculating the number of turns from the length l of the strip remaining up to the rolls 3 and the preset outside diameter DCP of the coil at the point of this time. The distance l2 at which the strip S moves until the top surface of the coil cars 5 arrive at the predicted coil outside diameter is calculated from the distance l1 from the top surface of the coil car rolls 5 prior to ascending up to the predicted coil diameter, the ascending speed v of the rolls 5 and the strip speed V. The ascending of the coil car rolls 5 is started to press the rolls 5 to the coil before the tail end of the strip passes through the pinch rolls 3 when the distance from the rolls 3 up to the tail end of the strip attains the distance l2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to a coil curl roll control force method for a down coiler in hot strip rolling.

[Prior art and its problems]

As shown in Fig. 4, in hot strip rolling,
The strip S leaving the final finishing stand passes through a runout table 2 and is wound up by a down coiler 1.

Just before the end of winding, when the tail end of the hot strip S passes through the pinch roll 3, the tension T on the hot strip S becomes zero, causing winding slack in the coil C and scratches, or A phenomenon in which the coil C comes apart occurs.

In order to prevent this, a pair of coil car rolls 5 are provided on the top of the coil car 4 placed at the bottom of the coil C, and the coil car rolls 5 are It is pressed against coil C.

Conventionally, for each coil, an operator constantly monitors the hot strip speed V and the tail end position of the hot strip S on a monitor, adjusts the timing for raising the coil car roll 5, and raises the coil car roll 5 manually.

Moreover, the pressing forces fI and f2 of the coil car roll 5 on the coil C at this time are constant.

Therefore, due to the synergistic effect of the slow rising timing of the coil car roll 5 and the constant pressing force fI r f2, flaws and unraveling occur due to loosening of the winding of the coil C, and touch flaws occur due to the pressing force f1 + f2. .

This caused a decline in quality and yield.

This invention was proposed in view of these circumstances.
The purpose is to prevent scratches and unraveling caused by loose winding of the coil.
An object of the present invention is to provide a coil car roll control method that can reduce and prevent touch flaws caused by roll pressing force. - [Means for solving the problem] The coil curl roll control force method of spear 1 according to the present invention detects the tail end of the strip with a detector installed on the upstream side of the pinch roll, and detects the tail end of the strip. At this point, from the remaining strip length t up to the pinch roll and the current coil outer diameter Dcp, calculate the number of turns to find the position of the predicted coil outer diameter Dcf when the strip tail end passes through the pinch roll, and calculate the position of the predicted coil outer diameter Dcf when the strip tail end passes through the pinch roll. The distance t2 that the strip S moves until the top surface of the coil car roll reaches the predicted coil diameter Dcf, given the distance 1+ to the predicted coil diameter t)cf, the rising speed of the coil car roll, and the strip speed V.
When the distance from the pinch roll to the tail end of the strip reaches distance t2, the coil car roll starts rising, so that the coil car roll can be pressed against the coil before the strip tail passes through the pinch roll. This is what I did.

In the method for controlling the coil curl roll of spear 2 according to the present invention, the tail end of the strip is detected by a detector installed on the upstream side of the pinch roll, and at the time of detecting the tail end, the remaining strip length l up to the pinch roll is determined. From the current coil outer diameter Dcp, calculate the number of turns to find the predicted coil outer diameter Dcf when the strip tail end passes through the pinch roll, and combine this predicted coil diameter Dcf with the coil circumferential speed (i.e. strip speed).
From this, the centrifugal circle and normal force Fw are calculated, and the coil car roll is moved with a pushing force equivalent to the centrifugal force FR until just before the coil rotation stops, and with a pushing force equivalent to the normal force just before the coil rotation stops. There are some types that are pressed against the surface to prevent touch scratches from occurring.

〔Example〕

The present invention will be described below based on an illustrated embodiment.

As shown in Figure 1, a detector 6 such as a hot-rolled copper strip detector (HMD) is installed at a distance upstream of the pinch roll 3, and a coil car 4 is controlled by a calculation/controller 7. As will be described in detail next, before the tail end of the strip S passes through the pinch roll 3, the coil car roll 5 is connected to the coil CK.
Automatically controls the pressure.・(i) The tail end of the strip S is detected by the detector 6, and from the remaining strip length t (=L) up to the pinch roll 3 at this point and the coil outer diameter Dcp, the number of turns is calculated to determine that the tail end of the strip is on the pinch roll. The predicted coil outer diameter Dcf when passing through 3 is calculated.

Here, as shown in Fig. 6, if a strip of plate thickness is intermittently wound n times around a coil of diameter Dc, then 1
The coil length of the first layer is (Dc-14)π, and the second layer is (Dc+
3h) π, ......The nth layer is (DC+(2n
-1) π), the first term (Dc+h)π, the last term (Dc
+(2rL-1)huπ, which is an arithmetic progression with a tolerance of 2hrc.

Therefore, the total length of a coil wrapped n times around a coil with a diameter of ■ is = (Dc - n + h - 32) π ----...
(1), and by solving the quadratic force equation for n, we get: The number of turns n when a long strip is continuously wound around a coil with diameter DC can be approximated by equation (2). .

Therefore, when the remaining 9 tubes of length t are wound around a coil with diameter Dcp, the number of turns n'' is as follows, and the diameter Dcp
If n is the number of turns of the coil, the predicted coil diameter is Dcf=2(np+n')+Dmd...
...(3) However, Dmd: Mandrel diameter.

The number of turns n of the coil diameter Dcp is the number of revolutions of the mandrel 8 from the start of winding to the detection of the tail end, or the number of turns n from the start of winding to the detection of the tail end.Measure the length of the IJ knob (2) Obtained by calculating using a formula, etc.

(11) Find the distance tl between the top surface of the coil car roll 5 on standby and the predicted coil diameter Dcf.

As shown in Fig. 2, the mandrel diameter is Dmd, and the roll 5
If the diameter of d1 is the distance between the mandrel and the center of roll 5 is A, then Dmd + d t = (A - (-1-) ) - σs - h (np
-1-7L')-'-(41 However, σS is the space factor of the coil.

(iii) Find the time t required for the top surface of the coil curler roll 5 to reach the predicted coil diameter Dcf.

t=Lr/υ...
...(5) However, ν is the rising speed h of the roll 5) The distance t2 that the strip S moves during the time t
seek.

12-V-t = (V/υ)tt (6
) However, (2) is the strip speed M. When the distance from the pinch roll 3 to the tail end of the strip S reaches distance t2, the automatic lifting of the coil car roll 5 is started.

That is, the time point when the tail end passes the detector 6 is used as a reference (passing distance=0), the moving distance L+ of the tail end is accumulated, and the following comparison is performed based on the absolute distance.

L - L, ≦12 In addition, the cumulative distance LI is L + = (number of mandrel times E) x π - Dc ...
- Obtained by (7).

As described above, the coil car roll 5 can be automatically pressed against the coil before the strip tail part passes through the pinch roll 3.

Next, a method for controlling the pressing force of the coil car roll will be described.

As shown in Figure 5, the centrifugal force FR and normal force Fw (coil load) generated by each coil change, and from just before the tail end of the strip passes through the pinch roll 3 until just before the coil stops rotating, , the centrifugal force F'R (normal force direction), which has a different magnitude generated for each coil, is calculated, and the corresponding pressing force (FRt + FR2) is determined.

The force generated just before the coil stops rotating changes from centrifugal force to normal force FW, so calculate the normal force FW for each coil and calculate the corresponding pressing force (Fw+ + FW2).
shall be.

Find the centrifugal force using the following formula.

PH=mrw2 However, ■=mandrel circumferential speed (strip speed) W: Coil weight normal force FW is determined by the following equation.

However, b: Pressure setting for pressing the plate width coil car roll is performed as follows.

FR= FRI + FR2=λA PRFW ”F
WI + FW2 ”λA P.

However, λ: Load pressure coefficient A: Piston effective area P: Pressure Since the roll 5 is not pressed with a pressing force greater than the force generated by the coil, the occurrence of touch flaws can be reduced and prevented.

〔Effect of the invention〕

As mentioned above, according to the present invention, the coil car roll can be automatically pressed against the coil before the tail end of the strip passes through the pinch roll, thereby reliably preventing flaws and unraveling due to loosening of the coil. In addition, the coil car roll is pressed with a pressing force that corresponds to the force generated by the coil, reducing the occurrence of touch scratches.

It is possible to prevent this problem, thereby improving yield and stabilizing quality.

[Brief explanation of drawings]

Figures 1 and 2 are a schematic front view and a schematic side view showing a device for implementing the control method according to the present invention, Figure 3 is a schematic diagram for explaining the relationship between the coil length and the number of turns, and Figure 4 is a schematic diagram for explaining the relationship between the coil length and the number of turns. The figure is a schematic diagram showing a conventional device, and Figure 5 is a graph showing centrifugal force and normal force for each coil. 1...Down coiler, 2...Runout table, 3...Pinch roll, 4...
...Coil car, 5...Coil car roll, 6
...Detection i, 7--Calculation/controller, 8...
...Mandrel.

Claims (2)

[Claims] (1) A method of controlling a coil car roll that operates just before the end of strip winding to hold down the coil, in which the tail end of the strip is detected by a detector installed upstream of the pinch roll, and the tail end is detected at the time when the tail end is detected. Then, from the remaining strip length up to the pinch roll and the current coil outer diameter, find the predicted coil outer diameter position when the tail end of the strip passes through the pinch roll, and calculate the predicted coil outer diameter position until the top surface of the coil car roll reaches the predicted coil outer diameter position. A method for controlling a coil car roll of a down coiler, characterized in that the distance the strip moves is calculated, and when the distance from the pinch roll to the tail end of the strip reaches the movement distance, the coil car roll starts rising. (2) A method of controlling a coil car roll that operates just before the end of strip winding to hold down the coil, in which the tail end of the strip is detected by a detector installed upstream of the pinch roll, and the tail end is detected at the time when the tail end is detected. Then, from the remaining strip length up to the pinch roll and the current coil outer diameter, calculate the predicted coil outer diameter when the tail end of the strip passes through the pinch roll, and from this predicted coil outer diameter and coil circumferential speed, calculate the centrifugal force and vertical force of the coil. The down coiler is characterized in that the drag force is calculated and the coil car roll is pressed against the coil with a pressing force equivalent to centrifugal force until just before the coil rotation stops, and with a pressing force equivalent to the vertical resistance just before the coil rotation stops. Coil car roll control method.