JPH10296314A - Equipment for hot-rolling band steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide highly efficient rolling equipment for band steel which is improved so that the sheet passing capacity of a finishing mill is not hindered. SOLUTION: A strip tip restraining device 8 which is movable from the outlet of a finishing mill 1 to a coiler 2 in synchronism with rolling speed while imparting a specified tension to the strip 6 by clamping the tip of the strip 6 which is delivered from the finishing mill 1 with at least a pair of pinch rolls is provided on a strip cooling line which is extended between the finishing mill 1 and the coiler 2 in hot rolling equipment for band steel. At the time of rotationally driving the pinch rolls which are provided in this strip tip restraining device 8, a driving device for imparting low rotational driving force required to adjust the relative position of the strip tip restraining device 8 and the strip 6 at the time of traveling at a fixed speed is provided on a traveling truck 9. On the other hand, an outside auxiliary driving device for imparting the initial high rotational driving force required to obtain a high circumferential speed which is equal to the rolling speed of the strip 6 at the time of stand-by of the strip tip restraining device 8 to the pinch rolls is provided in the outside of the strip tip restraining device 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot strip mill (hot strip mill).

[0002]

2. Description of the Related Art In a hot strip rolling mill, a strip rolled to a predetermined thickness by a finish rolling mill is formed by:
Before being wound up by the mandrel of the down coiler,
The strip is cooled to a predetermined winding temperature by a strip cooling line provided between the finishing mill and the down coiler. This strip cooling line is composed of a run-out table composed of hundreds of driven roller tables and a water spray type cooling device or a water laminar type cooling device, and the strip conveyed on the run-out table is a run-out table. The lower surface is cooled by cooling water injected from between the rollers, and the upper surface is cooled by cooling water injected from above the run-out table.

[0003]

When the strip is conveyed at a high speed by a roller table type run-out table as described above, a so-called flying phenomenon occurs in which the leading end of the strip floats upward.
This may hinder the introduction of the strip tip into the downcoiler. Therefore, the conveying speed must be suppressed to about 700 m / min until the end of the strip is wound around the mandrel of the down coiler, and the maximum capacity of the finishing mill (about 1500 m / min) cannot always be utilized.
Productivity was to be hindered.

As a technique for preventing such inconveniences, Japanese Patent Application Laid-Open No. 2-25214 proposes a method of attracting a strip to a run-out table by electromagnetic force. However, since the electromagnetic force has a property inversely proportional to the square of the distance, if a flying phenomenon occurs at the end of the strip due to some disturbance, it is practically impossible to adsorb it again on the run-out table. Is not sufficient as a measure for preventing high-speed transport by preventing the strip tip from flying.

Further, Japanese Patent Application Laid-Open No. 7-204723 proposes a device in which a guide plate for suppressing the flying of the leading end of a strip is provided on a traveling cart that travels with the strip sent from a finishing mill. However, since this technique does not have a function of pulling the leading end of the strip, it is not possible to obtain an effect of preventing a shape defect during cooling.

The present invention solves such a problem imposed on the prior art, that is, the inconvenience that a flying phenomenon occurs when a strip is conveyed at a high speed on a run-out table, and the passing capacity of a finishing mill is reduced. An object of the present invention is to provide a high-efficiency hot strip rolling equipment improved so as not to obstruct it.

[0007]

In order to achieve the above object, according to the present invention, a finish cooling system is provided on a strip cooling line extending between a finishing mill and a coiler in a hot strip rolling mill. Strip tip restraint device capable of moving in synchronization with a rolling speed from an outlet of a finishing mill to a coiler while applying a predetermined tension to the strip by nipping the tip of the strip sent from the rolling mill by at least a pair of gripping rolls. In rotating the gripping roll provided in the strip tip restraining device, the gripping roll uses a low-speed rotation driving force required for adjusting the relative position between the strip tip restraining device and the strip when the strip tip restraining device runs at a constant speed. While the drive unit for providing the same to the traveling carriage has a high speed equal to the rolling speed of the strip in the standby state of the strip tip restraining device. It was to be arranged external auxiliary drive for providing an initial high-speed rotation driving force required to obtain the speed to grasp the roll to the outside of the strip tip restraint system.

In particular, a gear device or a clutch device is provided so that the rotation driving force applied from the external auxiliary driving device to the gripping roll on the strip leading end restraining device can be instantaneously separated.

[0009]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 1 to 3 show a final stand of a finishing mill 1 in a hot strip rolling mill according to the present invention, a down coiler 2, and a strip cooling line 3 extending therebetween. I have. The strip cooling line 3 is composed of a large number of pinch rolls 4 and a cooling water jet device 5 which are arranged in a row at appropriate intervals in the sheet passing direction. The pinch rolls 4 and the cooling water injection devices 5 are alternately arranged in the passing direction.

Each of the pinch rolls 4 is composed of a pair of upper and lower rolls, and each of the rolls is supported so as to be capable of moving vertically. Each of the pinch rolls 4 sandwiches the upper and lower surfaces of the strip 6 sent from the finishing mill 1 with a predetermined pressing force, and is provided with a rotational driving force, and the rotational speed is freely controlled. I have. The cooling water injection devices 5 are vertically paired like the pinch rolls 4, and the pairs of the cooling water injection devices 5 are supported on the upper and lower surfaces of the strip 6 so as to be able to move toward and away from each other.
On the surface of the cooling water injection device 5 facing the strip 6,
A plurality of cooling nozzles are provided so that cooling water can be sprayed on the upper and lower surfaces of the strip 6.

A guide rail 7 extends in the strip cooling line 3 along the plate passing direction. The guide rail 7 includes a strip 6 sent from the finishing mill 1.
The strip tip restraint device 8 that runs while holding the tip of the strip is placed. This strip tip restraint device 8
The upper and lower guide rails 7 as shown in FIGS.
The lift is prevented by the wheels regulated by the above, and for example, the traveling cart 9 driven by a pinion gear meshing with a rack gear extending in parallel with the guide rail 7 and the strip 6 sent out from the finishing mill 1 The gripping roll 10 includes a pair of gripping rolls 10 that hold the ends from above and below, and a driving device 16 that applies a rotational driving force to the gripping rolls 10. Further, as shown in FIG. 4 or FIG. 5, in the vicinity of a position where the strip leading end restraining device 8 waits immediately near the exit side of the finishing mill 1, an external auxiliary driving device 13 separate from the strip leading end restraining device 8 is provided. Is provided. The external auxiliary driving device 13 includes a transmission device 14 through which the gripping roll 10 of the strip tip restraining device 8 at the standby position is provided.
Can be given a rotational driving force.

Before the leading end of the strip 6 is sent out from the finishing mill 1, as shown in FIG.
All the pinch rolls 4 and all the cooling water jetting devices 5 are waiting at positions vertically separated from each other in order to secure a running space for the strip tip restraining device 8. Then, the strip tip restraining device 8 finishes by the rotational driving force applied from the external auxiliary driving device 13 separate from the strip tip restraining device 8 through the transmission device 14 immediately near the exit of the final stand of the finishing mill 1. It is on standby in a state where the gripping roll 10 is rotated at a peripheral speed slightly higher than the sending speed of the strip 6 from the rolling mill 1.

At the same time as the leading end of the strip 6 is sent out from the finishing mill 1 or slightly earlier, the strip leading end restraining device 8 starts accelerating toward the down coiler 2, and the strip 6 is moved in a short time. Runs in synchronization with the rolling speed of

While the strip leading end restraining device 8 is accelerating, the circumferential speed of the gripping roll 10 and the rolling speed of the strip 6 are synchronized by rotating the gripping roll 10 so that the strip 6 is not damaged. Can be securely gripped. In particular, the peripheral speed of the gripping roll 10 is controlled by the finishing mill 1
By setting the peripheral speed to be slightly higher than the sending speed of the strip 6, the leading end of the strip 6 sent from the finishing mill 1 is retracted, and the leading end of the strip 6 can be surely grasped.

While the strip front end restraint device 8 is on standby, it is necessary to rotate the gripping roll 10 at a peripheral speed substantially equal to the strip sending speed from the finishing mill 1. Further, after the strip leading end restraint device 8 is synchronized with the speed of the strip 6, it is necessary to rotate the gripping roll 10 in order to change the relative position between the leading end of the strip 6 and the strip leading end restraining device 8. A drive device for rotating the gripping roll 10 at a peripheral speed substantially equal to the strip sending speed from the finishing mill 1 is relatively large. As a result, the weight of the strip tip restraint device 6 is increased, and the acceleration performance is reduced. That is, in the present invention,
Since the power required for rotating the gripping roll 10 up to a predetermined peripheral speed given during the standby of the strip tip restraining device 8 is given from the external driving device 13, the gripping roll 10 placed on the strip tip restraining device 8 The driving device 16
It suffices to have the rotational driving capability required for rotation to change the relative position between the leading end of the strip 6 and the strip tip restraining device 8 after the speed of the strip tip restraining device 8 and the strip 6 are synchronized. The weight of the tip restraint device 8 can be reduced.

Here, the transmission device 14, which is a transmission means of the rotational driving force applied from the external auxiliary driving device 13 to the gripping roll 10, needs to be able to release the power transmission instantaneously. It is preferable to use an apparatus. FIG. 4 shows an example in which the transmission device 14 is a gear device, and FIG. 5 shows an example in which the transmission device 14 is a clutch device.

In the case where the transmission device 14 is a gear device, the external auxiliary drive device 13 is arranged so that the gear meshes with the strip tip restraining device 8 at a predetermined standby position near the exit of the final stand of the finishing mill 1. Accordingly, when the strip leading end restraint device 8 is at a predetermined position, the rotational driving force of the external auxiliary drive device 13 can be transmitted to the grip roll 10. When the transmission device 14 is a clutch device, the pressing device 15 is actuated to bring the clutch into contact if the strip leading end restraining device 8 waits at the predetermined position I by, for example, a position sensor. The rotation driving force of the auxiliary driving device 13 can be transmitted to the gripping roll 10.

If the transmission device 14 is a gear device, the gears are disengaged when the strip leading end restraint device 8 starts running, so that power transmission is instantaneously released. When the transmission device 14 is a clutch device, the power transmission is instantaneously released by operating the pressing device 15 and releasing the clutch immediately before the strip leading end restraining device 8 starts running. At this time, the rotation driving force of the external auxiliary driving device 13 cannot be continuously applied to the gripping roll 10, but the gripping roll 10 maintains a substantially predetermined peripheral speed by its inertia.

Through the above, the strip tip restraining device 8 is
After the acceleration is completed, a constant speed running state is established in synchronization with the rolling speed. At this time, the strip tip restraining device 8 runs while applying a predetermined tension to the strip 6. Here, when the traveling speed of the strip tip restraining device 8 is slightly increased with respect to the rolling speed, the strip tip restraining device 8 can be moved to a portion of the strip 6 protruding from the holding roll 10. In this way, the gripping roll 10
Is slowly rotated to change the relative position between the leading end of the strip 6 and the strip leading end restraining device 8. Therefore, the speed of the strip leading end restraining device 8 is increased or decreased as needed to adjust the contact position of the gripping roll 10 to the strip 6. The change can prevent uneven wear of the gripping roll 10 and local overcooling of the strip 6, and can quickly separate the strip tip restraining device 8 from the strip 6 when the strip 6 reaches the down coiler 2. At this time, for example, if the driving torque of the gripping roll 10 is controlled by the driving device 16 provided in the strip tip restraining device 8 so that the predetermined tension is always applied to the strip 6, the rotation speed of the gripping roll 10 becomes This is automatically determined according to the relative speed between the tip restraint device 8 and the strip 6.

On the other hand, each pair of the pinch roll 4 and the cooling water jetting device 5 which have been evacuated both up and down move in order to approach the upper and lower surfaces of the strip 6 sequentially as the strip tip restraining device 8 passes. . And pinch roll 4
Not only does the strip 6 come into contact with the upper and lower surfaces of the strip 6 to prevent the strip 6 from sagging, but also its rotation speed is controlled so that the tension of the strip 6 is always maintained within a predetermined range. Further, the cooling water injection device 5 outputs the strip 6
Cooling water is sprayed toward both the upper and lower surfaces of the. In this way, the strip 6 is always cooled in a state where appropriate tension is applied, so that the plate shape after cooling is greatly improved. In addition, since the cooling water jetting device 5 can also be moved toward and away from the surface of the strip 6, the cooling water jetting device 5 can be brought close to the surface of the strip 6 after passing through the strip tip restraining device 8 to rapidly cool the strip 6. So you can
The cooling line length can be reduced. In addition, since the scale thickness generated on the surface of the strip 6 becomes thin, the load of pickling in the next step is reduced.

As shown in FIG. 3, when the tip of the strip 6 reaches the entrance of the down coiler 2, the gripping force of the gripping roll 10 of the strip tip restraining device 8 is released, and the speed of the strip tip restraining device 8 is reduced. Enhance. As a result, the strip leading end restraining device 8 moves away from the strip 6 to the end of the guide rail 7 and stops.

On the other hand, near the inlet of the down coiler 2, as shown in FIG. 3, a fluid ejecting device 11 for introducing the tip of the strip 6 into the down coiler 2 is provided. At the same time when the strip 6 is released from the strip tip restraining device 8, a pressurized fluid, for example, water, air, or the like is sprayed from the fluid ejecting device 11 toward the free end of the strip 6, and The tip is guided to the entrance of the down coiler 2. At this time, by giving the velocity component in the traveling direction of the strip 6 by the jet fluid,
The flow of the strip 6 into the inlet of the downcoiler 2 can be further smoothed.

When the strip 6 is wound on the mandrel of the down coiler 2, the back tension is always applied to the strip 6 by the pinch roll 4, so that the strip 6 is uniformly wound without loosening. Therefore, the strip 6 can be decelerated on the strip cooling line 3, so that the finishing mill 1 does not need to reduce the rolling speed at the tail end of the strip.

When the tail end of the strip 6 passes through the pinch roll 4, the tail end may swing up and down because the restraining force on the tail end of the strip is interrupted. By the electromagnetic suction device 12 built in
The stable running of the tail end of the strip is maintained. Then, even when the tail end of the strip reaches the down coiler 2, the tail end of the strip can be stabilized by the injection pressure from the fluid ejection device 11, so that it is not necessary to greatly reduce the transport speed of the tail end of the strip.

By the way, when one coil has been wound, the strip tip restraining device 8 must be returned to a predetermined standby position near the exit of the final stand of the finishing mill 1 in preparation for sending out the next strip. This return time is a loss time. In order to prevent the loss time from occurring, as shown in FIG. 7, a return line connected to the guide rail 7 parallel to the guide rail 7 provided on the strip cooling line 3 and connected to the guide rail 7 at the start end and the end is provided. A dedicated guide rail 31 may be provided, and two or more strip tip restraining devices 8 may be used by alternately reciprocating.

[0027]

EXAMPLE The hot strip rolling equipment shown in FIG. 1 was used to roll from a strip thickness of 25 mm after rough rolling to a finished plate thickness of 1.0 mm. The total weight of the strip tip restraining device 8 is 5
tonf, the strip feed speed from the finishing mill is 1200 m / min. When the leading end of the strip 6 reached a position 0.5 m before the gripping roll 10 of the strip tip restraining device 8, an acceleration force of 25 tonf was applied to the strip tip restraining device 8 to run the traveling carriage 9. The speed of the traveling carriage 9 is synchronized with the delivery speed of the strip 6 after about 0.4 seconds, at which point the strip leading end restraining device 8 is moved to about 4.1.
m, and the leading end of the strip 6 is
Reached a position protruding 3.6 m from the vehicle. The speed of the strip tip restraining device 8 was set to 1250 m / min, which was slightly higher than the speed at which the strip 6 was sent from the finishing mill 1.

In this embodiment, the strip tip restraining device 8
When rotating the gripping roll 10 placed on the traveling carriage 9, a driving force required for high-speed rotation equal to the rolling speed of the strip 6 given during standby of the traveling carriage 9 is supplied to an external auxiliary driving device 13 provided outside the traveling carriage 9. From the
On the strip leading end restraining device 8, only a driving device sufficient to give a driving force required for low-speed rotation of the gripping roll 10 necessary for adjusting a relative position between the traveling carriage 9 and the strip 6 at a constant speed traveling is provided. Is fine. Therefore, it is possible to reduce the weight of the strip tip restraining device 8 to 5 tonf, and it is possible to perform such rapid acceleration. Therefore, stable rolling has become possible.

[0029]

As described above, according to the present invention, after the tip of the strip sent from the finishing mill is mechanically restrained, the strip tip restraining device runs in synchronization with the feeding speed of the rolling mill. In addition, a certain tension is applied to the strip so that the cooling line can be passed through. Thereby, the occurrence of flying or meandering over the entire length of the strip can be prevented. Accordingly, since the speed of passing the cooling line can be increased in accordance with the capacity of the finishing mill, a great effect can be achieved in improving the productivity. In addition to this, a constant tension can be applied to the strip during cooling, and the cooling efficiency can be improved by bringing the cooling water injection device close to the strip, so that the cooling state is made uniform over the entire length of the strip. Thus, the quality of the strip can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a state before a strip in a facility of the present invention is passed through a cooling unit.

FIG. 2 is a schematic configuration diagram showing a state in which a leading end of a strip is passed through a cooling unit in the facility of the present invention.

FIG. 3 is a schematic configuration diagram showing a state in which a strip in the facility of the present invention is passed through a cooling unit.

FIG. 4 is a conceptual top view of a power transmission device using a strip tip restraint device and a gear device according to the present invention.

FIG. 5 is a conceptual top view of a power transmission device using a strip tip restraint device and a clutch device according to the present invention.

FIG. 6 is a conceptual side view of the strip tip restraint device according to the present invention.

FIG. 7 is a conceptual layout diagram of the equipment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Finishing rolling mill 2 Down coiler 3 Strip cooling line 4 Pinch roll 5 Cooling water injection device 6 Strip 7 Guide rail 8 Strip tip restraining device 9 Traveling trolley 10 Holding roll 11 Fluid injection device 12 Electromagnetic suction device 13 External auxiliary drive device 14 Transmission device 15 Pressing device 16 Drive device 31 Return-only guide rail

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Chihiro Yamaji 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation Technology Development Division (72) Inventor Yoji Nakamura 20-1 Shintomi, Futtsu-shi, Chiba New Japan Steel Technology Co., Ltd.

Claims (3)

[Claims] 1. A finishing mill and a coiler, a strip cooling line extending between the finishing mill and the coiler, and a strip cooling line extending from the finishing mill while restraining a leading end of the strip. In order to apply a predetermined tension, at least a pair of gripping rolls gripping the leading end of the strip, a driving device that applies a rotational driving force to the gripping rolls, and the strip cooling line from the finishing mill side to the coiler side. A strip leading end restraint device having at least a traveling carriage that can move in synchronization with the rolling speed, and an external auxiliary drive device that applies a rotational driving force to the gripping roll outside the strip leading end restraint device. And hot strip rolling equipment. 2. The hot-rolled steel strip according to claim 1, wherein the transmission of the rotational driving force applied from the external auxiliary driving device to the gripping roll on the traveling carriage is performed through a gear device. Facility. 3. The hot-rolled steel strip according to claim 1, wherein the transmission of the rotational driving force applied from the external auxiliary driving device to the gripping roll on the traveling carriage is performed via a clutch device. Facility.