JPH0623421A - Annealing device for strip tip and rear end - Google Patents

Abstract

PURPOSE:To prevent the occurrence of roll flaws then the strip tip and rear end bite into rolling rolls without grinding burrs. CONSTITUTION:The annealing device for the strip tip and rear end is composed of tip and rear end detectors 3 of a strip 2 arranged on the inlet side of a rolling mill 1, a heating device 5 having a strip clamping device and consisting of a heating burner freely movable in the traveling direction of the strip between the tip and rear and detectors 3 of the strip 2 and the rolling mill 1 and a heating control part 17 which clamps the specified length of the tip or the rear end of the strip 2 in the heating device 5 and moves the heating device 5 by the specified distance in synchronization with the strip passing speed while executing heating by the burner based on strip tip and rear end detection signals inputted from the tip and rear end detectors 3 of the strip 2 and the strip passing speed. Consequently, roll mark flaws of material to be rolled caused by the occurrence of the roll flaws can be obviated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when rolling a steel strip (hereinafter referred to as "strip") with a rolling mill, protects the front and rear end portions of the strip from the roll mark flaws such as top mark flaws and the like generated at the rear and rear end portions of the strip. Regarding equipment.

[0002]

2. Description of the Related Art When a strip is rolled by a cold rolling mill, various flaws are generated on the surface of the strip. One of the flaws is called a roll mark flaw. These roll mark flaws are dents on the surface of the roll caused by foreign matter that has jumped into the roll, traces of foreign matter on the strip, or traces of biting or slipping out of the work-hardened portion at the front and rear ends of the strip. The flaws generated on the roll are transferred to the strip surface as they are at the rotation cycle of the rolls, resulting in roll mark flaws.

Since there are various causes for the occurrence of roll flaws that cause roll mark flaws, effective countermeasures have not been taken. For example, an operator carefully observes the plate surface to roll The flaws were discovered early and the work rolls were replaced each time to minimize the roll mark flaws.

The largest cause of roll mark flaws is flaws caused by debris such as burrs that occur during shear cutting at the front and rear edges of the material to be rolled. As a method for preventing flaws due to debris such as burrs at the time of shear cutting, the leading and trailing edges of the strip are detected, and based on this detection, the roll rolling speed of the stand located on the strip advancing side is accelerated to increase the strip tension. Method of lowering and sequentially passing the tail end of the strip (Japanese Patent Laid-Open No. 51-133163)
Gazette), a strip passage table, a vertically movable strip tip fixing stopper that is inserted between the tables at right angles to the table, and a strip retainer for retaining the strip between the table and the strip tip. A device equipped with a rotatable brush having a body length equal to or larger than the full width of the strip at a position facing the fixing stopper through the strip tip (actual flat 1-878).
No. 53) is proposed. Further, as another method, there is a method of preventing the occurrence of roll mark flaws due to the leading and trailing ends of the strip by reducing the start of threading and the trailing edge removal work by making the tandem rolling machine continuous.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the method disclosed in Japanese Patent No. 3163, if the detection accuracy of the tail end position is poor, it is difficult to control the tension of the strip, and conversely, slip may occur between the work roll and the backup roll, resulting in a slip mark flaw. Is big. Also,
The device disclosed in Japanese Utility Model Laid-Open No. 1-87853 does not completely prevent the top mark due to the biting of the strip leading and trailing ends into the roll even if the burr generated at the shear cutting of the strip end is removed by a rotating brush. Can not. In addition, the continuous tandem rolling mill can reduce the occurrence of roll mark flaws due to biting or trailing edge of the strip front and rear ends, but the cost for facility modification is enormous and it is aimed at preventing roll mark flaws. Equipment modification is difficult.

It is an object of the present invention to soften the strip leading and trailing edges without grinding the burrs generated at the shear cutting of the strip edge and prevent the top mark flaw due to the biting of the leading and trailing edges into the rolling roll. It is to provide an annealing device.

[0007]

[Means for Solving the Problems] The inventors of the present invention have made extensive studies to achieve the above object. As a result, a heating device composed of a heating burner group having a strip clamp device on the inlet side of the rolling mill is movably arranged in the strip running direction, and before the strip tip and tail ends are caught in the rolling mill or before slipping out. , 1 from the strip tip and tail
Annealed by heating a range of 50 mm by a burner,
It has been clarified that it is possible to prevent the occurrence of dent defects on the roll surface and suppress roll mark defects by softening the work-hardened burrs and plate edges that occur at the strip front and tail ends, and arrived at the present invention.

That is, the present invention has a strip leading and trailing edge detector arranged on the inlet side of the rolling mill, and a strip clamp device between the strip leading and trailing edge detector and the rolling mill, which is movable in the strip running direction. A heating device consisting of a burner, a strip front and rear end detection signal inputted from the front and rear end detector of the strip, and a predetermined length of the front or rear end of the strip is clamped in the heating device based on the strip passing speed, It is an annealing device for strip front and rear ends, which comprises a heating control unit for moving the heating device by a predetermined distance in synchronization with the plate passing speed while heating the burner.

[0009]

In the present invention, the front and rear end detectors of the strip are arranged on the inlet side of the rolling mill, and the heating device arranged between the front and rear end detectors and the rolling mill is connected to the front and rear ends of the heating control section. A heating device that clamps a predetermined length of the leading or trailing edge of the strip based on the leading edge and trailing edge detection signals of the rolled material from the edge detector and the stripping speed, while synchronizing the burner heating with the striping speed. Since it is moved by a predetermined distance and annealed by burner heating, burrs, cutting powder, and other debris generated during shear cut in the previous process, which causes roll flaws existing at the strip's rear end, work-hardened strip's rear end The portion is softened, and roll scratches that occur when the strip front and rear ends are caught in the roll or slip off the roll can be prevented, and roll mark scratches on the strip can be suppressed.

The detector of the front and rear ends of the strip in the present invention is not particularly limited as long as it can detect the front and rear ends of the strip such as a photoelectric tube type, an electromagnetic type and a microwave type, but a photoelectric tube type is preferable. The clamping device provided in the heating device of the present invention is provided before and after the heating burner, that is, before and after the strip running direction, when the strip tip end is heated by the clamping device upstream from the heating burner, and when the strip tail end is heated. By clamping with a clamping device on the downstream side of the heating burner and moving for a predetermined distance, the strip front and rear ends can be sufficiently annealed. The heating burner of the heating device of the present invention is a burner group in which one row or a plurality of rows of burners are arranged at predetermined intervals in the plate width direction,
Alternatively, a high-speed jet burner having a single slit or a plurality of slits, which is disclosed in Japanese Utility Model Laid-Open No. 1-111919, can be used by being arranged in the plate width direction.

For example, in the case of the strip front end, the annealing of the strip front and rear ends in the present invention is detected by the front end detector when the strip front end is threaded, and the heating control unit causes the strip front end to have a predetermined length, for example, the front end. From 15
At the same time 0 mm enters the heating burner position of the heating device, the upper and lower clamp devices clamp the strip, start the supply of fuel gas and combustion air to the heating burner, start ignition and anneal, and synchronize with the strip running speed. Then, the heating device is moved by a predetermined distance. When the heating device moves a predetermined distance, the upper and lower clamp devices unclamp the strip, and the supply of fuel gas and combustion air to the heating burner is stopped. The annealing temperature in the heating device during this period is heated to a temperature at which the temperature of the transformation point or higher can be maintained for several seconds.

In the case of heating the strip tail end, when the strip tail end is detected by the front / rear end detector, the heating control unit causes the strip tail end to have a predetermined length, for example, a portion 150 mm from the tail end of the heating device. At the same time as entering the heating burner position, the upper and lower clamp devices clamp the strip, start supplying fuel gas and combustion air to the heating burner, ignite and anneal, and synchronize the heating device with the heating speed. Move a predetermined distance. When the heating device moves a predetermined distance, the upper and lower clamp devices unclamp the strip, and the supply of fuel gas and combustion air to the heating burner is stopped. The strip front / rear end annealing device of the present invention can be applied to the case where the tandem type rolling mill is not continuous, or to the improvement of the yield by reducing the off gauge in the lever type rolling mill.

[0013]

【Example】

Embodiment 1 The details of the annealing device for strip front and rear ends of the present invention will be described below with reference to FIGS. 1 to 4 showing an embodiment. FIG. 1 is a plan view showing the overall arrangement of an annealing device for strip front and rear ends of the present invention, FIG. 2 is a side view when heating the strip tip, FIG. 3 is a front view of the heating device, and FIG. It is a partial development perspective view. 1 to 4,
1 is a cold rolling mill, 2 is a strip to be supplied to the cold rolling mill 1, 3 is a front / rear end detector (phototube type) of a strip 2 provided on the inlet side of the cold rolling mill 1, and 4 is a side of the strip 2. Guides 5 are heating devices in which heating burners 6 are arranged between the side guides 4 and the cold rolling mill 1 in two rows at regular intervals in the strip width direction. The heating device 5 has a clamp device composed of clamp cylinders 7 and 8 and clamp members 9 and 10 in the front and rear of the traveling direction of the strip 2 of the heating burner 6, and is free to travel along the upper and lower guide rails 11 and 12. It is supported by the carriages 13 and 14 of the above through the lifting cylinders 15 and 16.

Reference numeral 17 denotes a heating control section, which detects the leading or trailing edge detection signal of the strip 2 input from the leading or trailing edge detector 3.
Based on the strip-passing speed of the strip 2, which is separately input, 150 mm from the strip end before the strip 2 tip and tail end bite into the work roll 1 of the cold rolling mill and before slipping out.
In order to anneal by heating the range of 150 mm, 150 mm from the tip of the strip 2 enters the heating burner 6 portion of the heating device 5, and at the same time, the clamp cylinder 7 is operated to clamp the strip 2 by the clamp member 9, 150 mm from the tip of the strip 2 by starting the supply of fuel gas and combustion air to the heating burner 6 of 5 and igniting
The traveling electric motor 1 of the carriages 13 and 14 while heating the burner
8 and 19 are controlled to travel a predetermined distance in synchronization with the strip passing speed, and then the clamp cylinder 7 is reversely operated to release the clamp of the strip 2 by the clamp member 9 so that fuel gas and combustion Turn off the air supply. When 150 mm from the tail end of the strip 2 reaches the heating burner 6 of the heating device 5, the clamp cylinder 8
Is operated to clamp the strip 2 by the clamp member 10, the supply of the fuel gas and the combustion air to the heating burner 6 of the heating device 5 is started and ignited, and the burner is heated up to 150 mm from the tail end of the strip 2, Trolley 13, 14
The traveling electric motors 18 and 19 are controlled to travel a predetermined distance in synchronization with the strip passing speed of the strip 2, and then the clamp cylinder 8 is reversely operated to release the clamp of the strip 2 by the clamp member 10. It is configured to stop the supply of gas and combustion air.

The strip 2 is constructed as described above.
Is passed through a cold rolling mill, and when the front end of the strip 2 passes through the front / rear end detector 3, the front / rear end detector 3 detects this and outputs it to the heating control unit 17. The heating control unit 17 receives the strip 2 front end detection signal input from the front and rear end detector 3,
At the same time that the 150 mm tip of the strip 2 enters the heating burner 6 portion of the heating device 5 based on the stripping speed separately input, at the same time, the clamp cylinder 7 of the heating device 5 is operated to clamp the strip 2 by the clamp member 9, The supply of fuel gas and combustion air to the heating burner 6 of the heating device 5 is started and ignited, and 150 m from the tip of the strip 2
While heating the burner up to m, the traveling electric motors 18 and 19 of the carriages 13 and 14 are controlled to travel a predetermined distance in synchronization with the strip passing speed of the strip 2, and then the clamp cylinder 7 is operated in the reverse operation to the clamp. The clamp of the strip 2 by the member 9 is released, and the supply of fuel gas and combustion air is stopped.

Further, the front / rear end detector 3 detects the passage of the tail end of the strip 2 and outputs it to the heating controller 17. Based on the strip 2 tail end detection signal input from the front / rear end detector 3 and the strip passing speed separately input, the heating control unit 17 sets the heating burner of the heating device 5 at a position within 150 mm from the strip 2 tail end. At the same time as reaching the 6th part, the clamp cylinder 8 is operated to clamp the strip 2 by the clamp member 10, and the heating burner 6 of the heating device 5 is
While starting the supply of fuel gas and combustion air and igniting, and heating the burner up to 150 mm from the tail end of the strip 2, the traveling electric motors 18 and 19 of the carriages 13 and 14 are controlled,
After traveling for a predetermined distance in synchronization with the strip passing speed of the strip 2, the clamp cylinder 8 is reversely operated to release the clamp of the strip 2 by the clamp member 10, and the supply of fuel gas and combustion air is stopped. When the annealing of the front and rear ends of the strip 2 is completed, the heating control unit 1
7 controls the traveling motors 18 and 19 of the carriages 13 and 14 to drive the carriages 13 and 14 to the annealing start position at the front and rear ends, and completes the annealing work.

Therefore, up to 150 mm from the tip and the tail end of the strip 2, respectively, are heated by the heating burner 6 of the heating device 5 so that the temperature above the transformation point can be maintained for several seconds, and are generated at the tip and the tail end of the strip 2. The work-hardened edges, burrs at the time of cutting, cutting powder, etc. are softened by annealing and then bitten into the work rolls of the cold rolling mill 1. Can be prevented.

Example 2 The strip leading and trailing end annealing device described in Example 1 was installed in a cold rolling mill, and the occurrence of roll flaws on the strip surface was measured one month before and after the installation. The result is shown in FIG. The roll flaw generation coil number ratio in FIG. 5 was obtained by dividing the roll flaw generation coil number by the rolling coil number. As shown in FIG. 5, the roll flaw generation coil ratio, which was 18% before the annealing device for the strip front and rear ends of the present invention was 18%, was 0% after the annealing device for the strip front and rear ends of the present invention was not present. And the effect is clear.

[0019]

As described above, according to the present invention,
It is possible to soften burrs and work hardened parts caused by shear cutting in the previous process, prevent roll flaws that occur when the material to be rolled is caught in the rolling mill or slipped out, and the roll mark of the material to be rolled You can eliminate all defects.

[Brief description of drawings]

FIG. 1 is a plan view showing the overall arrangement of a strip front / rear end annealing device of the present invention.

FIG. 2 is a side view at the time of heating the strip leading end.

FIG. 3 is a front view of the heating device of the present invention.

FIG. 4 is an exploded perspective view of essential parts of the heating device according to the present invention.

FIG. 5 is a graph showing the ratio of the number of roll flaw generation coils before and after the installation of the annealing device at the strip front and rear ends in Example 2.

[Explanation of symbols]

 1 Cold rolling mill 2 Strip 3 Leading and trailing edge detector 4 Side guide 5 Heating device 6 Heating burner 7,8 Clamp cylinder 9,10 Clamping member 11,12 Guide rail 13,14 Truck 15,16 Lifting cylinder 17 Heating controller 18 , 19 traveling electric motor

Claims (1)

[Claims] 1. A strip leading and trailing edge detector disposed on the inlet side of the rolling mill, and a heating burner having a strip clamp device between the strip leading and trailing edge detector and the rolling mill and movable in the strip running direction. Based on the strip leading and trailing edge detection signals input from the heating device and the strip leading and trailing end detectors, and the predetermined length of the strip leading or trailing end is clamped in the heating device based on the strip passing speed, and the burner is heated. An annealing device for the strip front and rear ends, which comprises a heating control unit that moves the heating device a predetermined distance in synchronization with the strip passing speed.