JPH11277133A - Controlling method of coiling pinch roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent slack between a downstream side coiling device and a upstream side coiling device after the tail end of a strip which is coiled with the downstream side coiling device runs past an upper side coiling pinch roll at the time of switching the strip from the downstream side coiling device to the upstream side coiling device. SOLUTION: In this controlling method, a strip which is sent out of a hot finishing mill is cut into a prescribed length with a strip shear 2, and cut strips are alternately coiled with plural coiling device 4, 1 via coiling pinch rolls 3, 5. In such a case, the relation among a target speed Vp1 of the downstream side coiling pinch roll 3, a target speed Vp2 of the upstream side coiling pinch roll 5, a target plate speed Vs of the strip S1 just before cutting and a set coiling speed Vm of the coiling device at the time when the tail end of the strip S1 which is coiled onto the coiling device 4 via the coiling pinch roll 3 in the downstream side is cut with the strip shear 2 is specified to Vm > Vp1 >Vp2 >Vs .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a strip fed from a hot rolling mill into a predetermined length by a strip shear and winding the cut strip into a plurality of rolls via a pinch roll for winding. The present invention relates to a method for controlling a winding pinch roll when winding is alternately performed by a winding device.

[0002]

2. Description of the Related Art FIG. 3 schematically shows a continuous hot rolling line. Conventionally, switching of a winding device when a strip cut to a predetermined length by a strip shear is alternately wound by a plurality of winding devices has been performed as follows.
As an example, the case of switching from the downstream winding device a to the upstream winding device b will be described. The strip d sent from the finishing mill c is subjected to a predetermined operation by a strip shear e located immediately before the upstream winding device b. The strip is cut into lengths, and the leading strip d ₁ and the trailing strip d ₂ are wound by the downstream winding device a and the upstream winding device b, respectively.

[0003] The leading strip d ₁ while wound on the downstream side take-up device a, to move the lower pinch roll g upstream take-pinch roll f to the upstream side, thereby, preparative upstream winding by changing the offset angle of the pinch roll f keep switching the transport direction of the strip from the advance downstream winding device a upstream winding device b, leading strip d ₁ has passed through the pinch roll f preparative upstream winding induces trailing strip d ₂ on the upstream side winding device b immediately. At this time, the trailing strip d ₂ is moved by the triangular gate j to the downstream winding device a.
Prevent it from penetrating to the side.

Prior to the cutting, the strip is pressed by the upper pinch roll h of the upstream winding pinch roll f with the offset angle changed to hold the strip. This is because the can not take so large a preceding distance between the tip of the tail and the trailing strip d ₂ strips d ₁ resulting from cleavage, after the tail end has passed the pinch roll f preparative upstream winding Until the tip reaches the position of the upstream winding pinch roll f, the lower pinch roll g of the upstream winding pinch roll f is offset to the upstream side, and the tail end is moved to the upstream side. This is because there is not enough time to depress the upper pinch roll h to the gap setting position for feeding the sheet into the winding device.

[0005]

However, in such a conventional method of controlling a pinch roll for winding, when the strip is cut by a strip shear e, the strip is cut by a finishing mill c and a downstream winding device a until then. The applied tension is released, and the preceding strip loosens between the upstream winding pinch roll f and the downstream winding pinch roll i as shown in FIG. In the worst case, there is an inconvenience that the plate is damaged by being caught on the triangular gate g.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and when switching from the downstream winding device to the upstream winding device, the tail end of the strip wound by the downstream winding device is located on the upstream side. An object of the present invention is to provide a control method of a winding pinch roll that can prevent looseness between a downstream winding device and an upstream winding device after passing through the winding pinch roll. .

If the pushing force of the upper pinch roll on the strip when the offset angle of the upstream winding pinch roll is changed is weak, the tail end of the strip wound by the downstream winding device is moved to the upstream winding. Since the strip end cannot be sufficiently held by the pinch roll, the tail end of the strip cannot be pressed by the upstream wind pinch roll and slips. As described above, the downstream winder and the upstream winder may be slipped. (See FIG. 5). Therefore, it is desired to set a pressing force that can reliably pinch the strip with the upstream winding pinch roll.

[0008]

In order to achieve the above object,
A method for controlling a winding pinch roll according to claim 1.
Strip strips from the rolling mill
Cut to a predetermined length with a
Is wound by a plurality of winding devices via a winding pinch roll.
Control of the winding pinch roll when winding alternately by
A method of winding via a take-up pinch roll on the downstream side.
The tail end of the strip to be taken up by the take-up device.
Pinch roll for winding on the downstream side when cut by pusher
Target speed V_p1, The target speed of the upstream winding pinch roll
Degree V_p2, Target strip speed V of the strip immediately before the cutting_SPassing
And the set winding speed V of the winding device_mThe relationship of V_m> V_p1
> V _p2> V_SIt is characterized by having.

According to a second aspect of the present invention, there is provided a method of controlling a take-up pinch roll according to the first aspect, wherein the lower pinch roll is offset from the upstream take-up pinch roll via the take-up pinch roll. The pressing force of the upper pinch roll on the upstream winding pinch roll against the strip to be wound on the winding device is determined by the tension of the strip, the radius of the upper pinch roll, and the contact arc between the upper pinch roll and the strip. Is set based on the projection length relationship.

According to a third aspect of the present invention, there is provided a method for controlling a winding pinch roll according to the first aspect, wherein the lower pinch roll of the upstream winding pinch roll is offset and then the downstream pinch roll is rotated via the winding pinch roll on the downstream side. for Te winding strips of tail taken to the winding device until the cut in the strip shear, the speed of the lower pinch roll the winding upstream while slower than the target plate velocity V _S of the strip Push the strip until the actual torque value of the lower pinch roll reaches a predetermined set value by the upper pinch roll of the pinch roll, and press the set force of the upper pinch roll against the strip when the pressing force at this time is offset. It is characterized by power.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram for explaining a method of controlling a winding pinch roll as an example of an embodiment of the present invention, and FIG. 2 is an explanatory diagram for explaining a method of setting a pressing force.

FIG. 1 schematically shows a portion of a continuous hot rolling line on the downstream side of a strip shear. In this embodiment, a strip fed from a finishing mill (not shown) is used. It is cut to a predetermined length by a strip shear 2 located immediately before the upstream winding device 1, and the preceding strip S ₁ is wound by the downstream winding device 4 via the downstream winding pinch roll 3, and taking a case where the line strip S ₂ through the pinch rolls 5 preparative upstream winding wound by the upstream winding device 1 as an example.

The downstream and upstream winding devices 4, 1 are both
As means for pulling the strip wound around the mandrel 7 with a predetermined winding tension, a motor 8 of the mandrel 7 is used.
A torque detector 9 for detecting the torque of the
A torque control device 10 that performs feedback control of the motor 8 so as to maintain the strip tension constant so that the detected torque value obtained by the above operation matches the target torque value;
A pilot generator (PLG) 11 for detecting a rotation state of the motor 8 and a speed control device 12 for performing feedback control of the motor 8 so that a detected speed value obtained by the pilot generator 11 matches a target speed.

The downstream winding pinch roll 3 includes a torque detector 14 for detecting a torque of a motor 13 of the lower pinch roll 3a, a pilot generator (PLG) 15 for detecting a rotation state of the motor 13, and a pilot generator (PLG) 15. The detected speed value obtained by the generator 15 is the target speed V
a speed control device 16 for feedback-controlling the motor 13 so as to coincide with _p2 .

Similarly, the upstream winding pinch roll 5 also includes a torque detector 18 for detecting the torque of the motor 17 of the lower pinch roll 5a, and a pilot generator (PLG) 19 for detecting the rotation state of the motor 17. And a speed control device 20 that performs feedback control of the motor 17 so that the speed detection value obtained by the pilot generator 19 matches the target speed V _p1 . The lower pinch roll 5 a is upstream from the downstream winding device 4. When changing the offset angle at the time of switching to the side take-up device 1, it can be moved along the pass line to the upstream side, and the upper pinch roll 5b can press the strip via the hydraulic cylinder 21 to push down the strip. I have. A pressing force detector 22 for detecting a pressing force applied to the upper pinch roll 5b is attached to the upper pinch roll 5b.

The pressing force applied to the upper pinch roll 5b via the hydraulic cylinder 21 is determined by the pressing force detected by the pressing force detector 22 set in advance by the pressing force setting device 23 or the compensating pressing force setting device 24. It is determined by feedback control of a servo valve 27 that switches oil supplied from the hydraulic pump 26 to the hydraulic cylinder 21 by the pinch roll pressing force control device 25 so as to match the pressing force.

Next, switching from the downstream winding device 4 to the upstream winding device 1 will be described. First, while the preceding strip S ₁ is being wound by the downstream winding device 4, the upstream winding device 4 is switched to the upstream winding device 1. The lower pinch roll 5a of the take-up pinch roll 5 is moved upstream along the pass line by a hydraulic cylinder (not shown) or the like, thereby changing the offset angle of the upstream take-up pinch roll 5. the conveying direction of the strip advance switching in advance from the downstream side take-up device 4 on the upstream side winding device 1, the upstream side of the trailing strip S ₂ immediately after the leading strip S ₁ is passed through the pinch rolls 5 preparative upstream winding The device can be guided to the winding device 1. In FIG. 1, the reference numeral 28 indicates that the succeeding strip S ₂ is the downstream side winding device 4.
It is a triangular gate to prevent it from penetrating to the side.

In a case where the strip is cut by the strip shear 2 in a state where the preceding strip S ₁ is wound around the downstream winding device 4, in the present invention, when the cutting is performed, the speed control device 12 of the winding device 4 is used. target speed with respect to the preceding strip S ₁ set winding speed V _m, the target speed V _p2 for the pinch roll 5 side of the speed controller 20 prep upstream winding, downstream take-pinch roll 3 side of the speed control device 16 by V _p1 and the transport speed of the preceding strip S ₁ immediately before cutting are represented by V _S , by a host computer (not shown).
It is set so that V _m > V _p1 > V _p2 > V _S.

By performing such a speed setting,
It is assumed that the tail end of the preceding strip S ₁ is loose between the winding device 4 and the downstream winding pinch roll 3 and between the downstream winding pinch roll 3 and the upstream winding pinch roll 5. prevention can also be prevented damage to the strip S ₁ by being caught in a triangular gate 26. Further, since the greater value the setting winding speed V _m than the conveying speed V _S of the leading strip S ₁ immediately before the cutting, can be made difficult to occur the looseness of the tail end, also leading strip after cutting intervals can be provided to the tip of the tail and the following strip S ₂ S _1.

Further, it is preferable that the preceding strip S ₁ is securely held by the upstream winding pinch roll 5 before the cutting is performed. At this time, when the pressing force setting device 22 of the upstream winding pinch roll 5 is installed on the upper pinch roll 5b side as shown in FIG.
_When the offset angle of the upstream winding pinch roll 5 is changed while ₁ is wound around the downstream winding device 4,
The preceding strip S ₁ is pushed down from the pass line in accordance with the offset amount of the lower pinch roll 5a, and the strip S _{1 is} pushed down.
Must be held between the upper and lower pinch rolls 5b, 5a. In the example shown in FIG. 1, the leading strip S ₁ is pressed by the upper pinch roll 5 b of the upstream winding pinch roll 5 via the hydraulic cylinder 21, and the pressing force at this time is set by the pressing force setting unit 23. Alternatively, it is set by the compensating pushing force setting device 24.

First, pressing force setting by the pressing force setting device 23
Starting with the method, referring to FIG.
The reaction force P (N) acting on the multi-roll 5b is
S ₁And the radius of the upper pinch roll 5b to F (N).
R (m), leading strip S ₁And the upper pinch roll 5b
L (m) is the projected length of the contact arc of₁To
Reaction force received from the lower pinch roll 5a through the
Trip S₁If the force for holding is ΔP, then P = L · F / R + ΔP (1)

Therefore, the pressing force setting device 23 uses the formula (1) to set the force equal to or higher than the reaction force P as the set pressing force of the upper pinch roll 5b, and the detected pressing force obtained by the pressing force detector 22 determines the setting. The servo valve 27 is feedback-controlled by the pinch roll pressing force control device 25 so as to match the pressing force. Here, ΔP may be set to a value obtained by empirically determining a pressing force value that does not cause the sandwiched strip to slip with the pinch roll.

Next, a method of setting the pressing force by the compensating pressing force setting device 24 will be described. Compensation pushing force setter 24 is for setting the compensation pressing force to reliably pinch the leading strip S ₁ by the pinch rolls 5b and the lower pinch roll 5a on the pinch rolls 5 preparative upstream winding, upstream after the offset angle change of the pinch rolls 5 preparative side winding, in an appropriate timing until the tail cutting of leading strip S ₁ by the strip shear 2, the speed reference of the lower pinch roll 5a by controlling the speed controller 20 The speed is set slightly lower than the plate speed V _S of the preceding strip S ₁ , and in this state, the torque detector 18
The servo valve 26 is feedback-controlled via the pinch roll pressing force control device 25 until the torque value T detected by the control reaches the preset set value T ₀ , and the strip S ₁ is kept pressed.

[0024] When it is slightly slower than the plate velocity V _S of the preceding speed reference of the lower pinch roll 5a strip S _1, the leading strip S ₁ at a desired pressing force is not pressed against, a load on the lower pinch roll 5a while not increase the torque of the lower pinch roll 5a for not significantly, the leading strip S ₁ at a desired pressing force is pressed against the load leading strip S ₁ is caused to slip between the lower pinch roll 5a ( Torque) increases. By using this, the compensation set pushing force (in this case, the leading strip S
Estimate a force) P _S (N) sandwiching ₁ between the upper pinch roll 5b and the lower pinch roll a.

That is, the force P _S (N) for sandwiching the preceding strip S ₁ between the upper pinch roll 5b and the lower pinch roll a.
Is a speed difference between the preceding strip S ₁ and the lower pinch roll 5a Delta] v (mpm), the friction coefficient of the leading strip S ₁ and the lower pinch roll 5a which changes the speed difference Delta] v mu ₂
(Δv), the actual torque of the lower pinch roll 5a is represented by T (N ·
m), assuming that the radius of the lower pinch roll 5a is r (m), P _S = T / [r · μ ₂ (Δv)] (2)

Therefore, from the equation (2), the predetermined speed difference Δv
If the value of μ ₂ at the time of is determined in advance, the compensation set pushing force P _S can be determined by measuring the actual torque T of the lower pinch roll.

How to Set Pushing Force Using Compensating Pushing Force Setter 24
In the method, cutting is performed by the strip shear 2
Also preceding strip S₁So that the tail end of the
Strip S with side take-up pinch roll 5₁Can pinch
The compensation setting pushing force Ps₁Is determined in advance and the cutting is performed.
Before setting the speed of the lower pinch roll 5a to the strip S₁of
Sheet speed V_SIf it is set to be lower by a predetermined speed Δv than
The compensation setting pushing force is Ps ₁Lower pinch roll when
Torque value T of 5a₀To the compensating push force setting unit 24 in advance.
Set it. The compensating push force setting device 24 is
Before cutting, the speed of the lower pinch roll 5a is
Sheet speed V_SSpeed control device 2 so as to be delayed by Δv
After sending a signal to 0, the actual torque of the lower pinch roll 5a
While measuring T using the torque detector 18,
Strip S by roll 5b₁As if pushing
To the pinch roll pressing force controller 25. Soshi
And the actual torque T is₀The above value is assumed. For this reason,
Strip S₁Is secured by the upstream winding pinch roll 5.
It can be in a state of being actually pinched. In this state,
Preceding strip S by strip shear 2₁The tail end of
Make a cut. The speed of the lower pinch roll a at the time of the cutting
As for the setting, satisfy the above equation (1) before cutting.
There is a need to.

As described above, the method for setting the pressing force of the upstream winding pinch roll based on the above equation (1) (method using the pressing force setting device 23) or the method for setting the lower pinch roll 5
based on the actual torque of a, the method of generating a compensation set pushing force P _S to the pinch rolls preparative the upstream side winding (the method according to the compensation pressing force setter 24), leading strip S by pinch rolls preparative upstream winding ₁ can be pinched. Here, the case of using the pressing force setter 23, prior since the strip has set pressing force by considering the tension of S _1, pinch roll the leading strip S ₁ preparative upstream winding 5
Pinch roll 5b and can be sufficiently pinched by the lower pinch roll 5a on the, also, in the case of using the compensation pressing force setter 24, the pushing force in consideration of the actual force on the leading strip S ₁ Since it is set, the preceding strip S ₁
Can be reliably held between the upper pinch roll 5b and the lower pinch roll 5a of the upstream winding pinch roll 5.

[0029] Therefore, as in the prior art, leading to the tail end of the strip S ₁ slip without being pressed by the pinch rolls 5 preparative upstream winding it can be eliminated thus in the same manner as described above, leading strip S ₁ It is possible to favorably prevent looseness between the downstream winding device 1 and the upstream winding device 6 at the tail end.

Note that V _m > V _p1 by the host computer
> V _p2 > V _S, and the pressing of the preceding strip S ₁ by the pressing force setting device 23 or the compensating pressing force setting device 24 is performed until the tail end of the preceding strip S ₁ is wound by the upstream winding device. Will be

[0031]

As is apparent from the above description, according to the first aspect of the invention, the tail end of the strip wound by the downstream winding device cut by the strip shear has passed through the upstream winding pinch roll. Since it is possible to prevent looseness between the downstream winding device and the upstream winding device later, it is possible to prevent the strip tail end from being caught and damaged by the triangular gate. .

According to the second aspect of the invention, in addition to the first aspect, the strip tail end wound by the downstream winding device can be satisfactorily held by the upstream winding pinch roll. An effect is obtained that the strip tail end can be prevented from slipping due to being not pressed by the upstream winding pinch roll.

According to the third aspect of the invention, in addition to the first aspect of the invention, the tail end of the strip wound by the downstream winding device can be securely held by the upstream winding pinch roll. An effect is obtained that the slip between the tail end of the strip and the upstream winding pinch roll can be reliably eliminated.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining a control method of a winding pinch roll as an example of an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a setting method of a pressing force.

FIG. 3 is an overall schematic view of a continuous hot rolling line.

FIG. 4 is an explanatory diagram for explaining a conventional method of controlling a winding pinch roll.

FIG. 5 is an explanatory diagram for explaining a conventional method of controlling a winding pinch roll.

[Explanation of symbols]

S ₁ : leading strip S ₂ : trailing strip 2: strip shear 3: downstream pinch roll 5: upstream pinch roll 5 b: upper pinch roll for upstream pinch roll 5 a: upstream Lower pinch roll for winding pinch roll 1 ... Upstream winding device 4 ... Downstream winding device 28 ... Triangle gate _Vp1 ... Target speed of downstream winding pinch roll _Vp2 ... Upstream winding pinch roll Target speed of V _S … Target plate speed of strip P, P _S … Pressing force F… Tension of strip R… Radius of upper pinch roll L… Projection length of contact arc between upper pinch roll and strip T… Low pinch roll Actual torque value of T ₀ … Set value

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Satoshi Shibuya 1-chome, Kawasaki-dori, Mizushima, Kurashiki-shi, Okayama Prefecture (No. Nan) Inside Mizushima Works, Kawasaki Steel Corporation (72) Inventor Kiyoshi Ueda Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba No. 1 Kawasaki Steel Corporation Chiba Works

Claims (3)

[Claims] When a strip sent from a rolling mill is cut into a predetermined length by a strip shear and the cut strip is alternately wound by a plurality of winding devices via a winding pinch roll. The method for controlling a winding pinch roll according to the above, wherein a downstream end of the strip wound by a winding device via the winding pinch roll at the downstream side is cut by the strip shear. The relationship between the target speed V _{p1 of} the pinch roll for cutting, the target speed V _{p2 of} the pinch roll for winding on the upstream side, the target plate speed V _S of the strip immediately before the cutting, and the set winding speed V _m of the winding device is represented by V. _m > _Vp1 > _Vp2 > V
_A method for controlling a pinch roll for winding, wherein the method is _S. 2. An upstream winding pinch roll for a strip wound by a winding device via a winding pinch roll on a downstream side when the lower pinch roll is offset from an upstream winding pinch roll. The pressing force of the upper pinch roll is set based on a relationship between a tension of the strip, a radius of the upper pinch roll, and a projection length of a contact arc between the upper pinch roll and the strip. 2. The method for controlling the winding pinch roll according to 1. 3. After the lower pinch roll of the winding pinch roll on the upstream side is offset, the tail end of the strip wound on the winding device via the winding pinch roll on the downstream side is cut by the strip shear. until that define actual torque value of the lower pinch roll by the upstream side of the take-pinch pinch roll on the roll in the state of speed of the lower pinch roll slower than the target plate velocity V _S of the strip in advance 2. The winding pinch roll according to claim 1, wherein the strip is pushed until the set value is reached, and the pushing force at this time is set as the pushing force of the upper pinch roll with respect to the strip when the offset is performed. Control method.