JP3420011B2 - Straightening device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a correction device.
More specifically, the present invention relates to a straightening device that is installed in a continuous annealing furnace that runs a steel sheet using a support roll or a floating type continuous annealing furnace that floats a steel sheet by a floater to run the steel sheet, and corrects the shape of the steel sheet.

[0002]

2. Description of the Related Art As a conventional continuous annealing furnace, for example, a floating type continuous annealing furnace comprises a pre-tropical NOF, a heating zone HF, and a cooling zone CF as shown in FIG. Steel plate (original plate) P is backup roll B
After being supported by R and supplied to the furnace, while being floated by a plurality of floaters F installed at predetermined positions in the heating zone HF and traveling, the heating means H arranged above and below the steel plate P It is configured to be heated.

The steel sheet supplied into the continuous annealing furnace is
Since it is cold-rolled, it does not have a uniform shape and dimensions, and shape defects such as in-stretching and selvage waves are generated. The line tension being pulled is, for example, 0.7 to 1.0 kg / mm.
It is corrected by raising it to ² or more.

[0004]

However, in the annealing furnace, the steel sheet expands in the sheet width direction, and tensile stress acts in the running direction due to the line tension to generate buckling stress in the sheet width direction. The flow velocity of the gas blown from the floater to the lower surface of the steel plate is 20 to 80 m /
Since the flow velocity of the jet gas flowing in the width direction of the steel sheet is 10 to 50 m / sec, the distribution of the levitation pressure just below the steel sheet is in a moderately high state. Furthermore, when the heating step in the annealing furnace is changed to the cooling step, the rate of change in the plate width changes significantly, so that a component force acts in the plate width direction.
As a result, as shown in FIG. 8, the steel sheet is likely to be curved so as to have an upward convex shape in the sheet width direction, that is, it is likely to be C-warped, and the annealed steel sheet has a bending amount of 10 to 5 at the center portion of the sheet width.
Since a shape defect of about 0 mm occurs, the line tension must be reduced to 0.4 kg / mm ² or less. In addition, since high temperature treated materials such as high-quality materials that require high quality or high-grade materials that have a thin plate thickness are likely to cause C warping, the line tension must be extremely low, 0.25 kg / mm ² .

However, the line tension is 0.7 kg / mm ²
If it is lower than the above range, there is a problem that the defective shape portion is not corrected and remains in the product, and the defective shape portion is not completely annealed.

On the other hand, it is possible to improve the above-mentioned shape defect by increasing the precision of cold rolling, but the adjustment of the bending force and the shift amount of the intermediate roll are very delicate and the adjustment is accurate. Is difficult. Therefore, in order to prevent the defective shape from occurring in the process before the annealing process, enormous capital investment such as the addition of a stand of the TCM rolling mill is required.

Therefore, it is conceivable to stretch the steel sheet with a leveler roll, but if the steel sheet is stretched while rotating the leveler roll, the following problems may occur. That is, the plate temperature of the passing steel plate changes depending on the steel type and the plate passing speed may change during normal operation. Although the elongation rate of the steel sheet changes due to the change of the plate temperature, it is difficult to synchronize the rotation speed of the leveler roll and the sheet passing speed of the steel sheet corresponding to the change of the elongation rate. Therefore, if the speeds of the leveler roll and the steel plate deviate from each other, chattering marks are generated on the steel plate. Then, if the pressure is continued in the state of the speed deviation, the leveler roll is picked up by sludge of the steel plate or iron powder, and the steel plate is flawed. Further, when the pickup grows, it becomes scratched and more easily scratches the steel plate. Therefore, when pick-up or scratches occur, the foreign matter attached to the leveler roll must be removed. In this removal work, the drive of the leveler roll is released, the leveler roll is pressed against the steel plate,
Differential speed polishing is performed in which the leveler roll is polished while slowly rotating the roll. However, such removing work is very complicated work and must be performed frequently.

In view of the above facts, an object of the present invention is to provide a straightening device capable of straightening a warp generated in a steel plate in a furnace with a leveler roll to obtain a flat steel plate.

[0009]

A straightening device of the present invention is a straightening device installed in a continuous annealing furnace for straightening the shape of a steel sheet, and includes a support roll and an upper portion for pressing the steel sheet from above. A leveler roll, an elevating means for elevating and lowering the upper leveler roll, and the upper leveler roll.
Lower leveler installed on the downstream side to press the steel plate from below
Roll and lifting means for lifting the lower leveler roll
And the roll diameter of the upper leveler roll is 10
A 0-200 mM, during which the upper leveler rolls are pressed steel plate, together with the upper leveling rolls, which are rotatable by a non-driving, the lower leveler
The roll diameter of the roll is 200 to 400 mm.
While the lower leveler roll is pressing the steel plate,
The partial leveler roll is rotatably driven without being driven .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A correction device of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an explanatory view showing an example of a floating type continuous annealing furnace equipped with the straightening device of the present invention, FIG. 2 is a side view showing an embodiment of the straightening device of the present invention, and FIG.
-I cross-sectional view, FIG. 4 is a II-II cross-sectional view, FIG. 5 is a schematic diagram showing correction of a warp shape of a steel plate, and FIG. 6 is an explanatory view showing a temperature drop in a cooling zone.

As shown in FIG. 1, the floating type continuous annealing furnace has a pre-tropical NOF, a heating zone HF, and a cooling zone C.
The strip-shaped steel sheet P made of F and supplied into the continuous annealing furnace is pulled from the exit side 1 of the furnace, and the steel sheet P is floated by a plurality of floaters F installed at predetermined positions of the heating zone HF. The steel plate P is configured to be heated by the heating means H while the steel plate P is being passed through. The pre-tropical NOF may be a non-oxidizing pre-tropical that is rapidly heated to shorten the annealing time. A slow cooling zone BZ may be provided behind the cooling zone CF.

As a straightening device 2 installed in the floating type continuous annealing furnace, as shown in FIGS. 2 to 5, a support roll 3 arranged below a pass line L in the traveling direction of the steel sheet, and the pass It is composed of an upper leveler roll 4 arranged above the line L, and an elevating means A for elevating the upper leveler roll 4. In the present invention, the upper leveler roll 4 is, so to speak, a C warp straightening roll.

The straightening device 2 includes an upper leveler roll 4
Thus, the steel plate P is pressed so that the elongation rate of the steel plate P is, for example, 0.2%, and the C-warped shape of the steel plate P is corrected.
When the upper steel leveler roll 4 is rotationally driven to impart elongation to the steel sheet P, the steel sheet P may be flawed.

Therefore, the present invention is characterized in that, while the upper leveler roll is pressing the steel sheet, the upper leveler roll is not driven and is rotatable, that is, in an idling state.

The support roll 3 has both shaft end portions 5 thereof.
Is supported by a bearing 7 fixed to a side wall 6, and drives a sprocket 9 fixed to one shaft end 5 and a chain 10 wound around a sprocket (not shown) of a motor (not shown). By doing so, it can be rotated.

The upper leveler roll 4 has both shaft end portions 11 inserted through the long holes 12 formed in the side wall 6 and supported by bearings 14 fixed to the side portions of the slider 13. The slider 13 is inserted into the guide member 15 attached to the side wall 6,
It can be moved up and down by an elevating means A connected to the lower part.

The raising / lowering means A for the upper leveler roll 4 is composed of, for example, a worm jack 16 and a motor 17 so that the amount of reduction can be adjusted. The worm jacks 16 on both sides are connected by a connecting rod 18 in a synchronized manner. The reduction amount can be adjusted by rotational position control, for example, the encoder 19.

The roll diameter of the support roll 3 is about 100 to 200 mm in order to support the steel plate P from below. On the other hand, the roll diameter of the upper leveler roll 4 is for correcting the C warpage of the steel sheet, so the thinner it is, the better, but since strength is also required, it is about 100 to 200 mm, preferably about 150 to 170 mm. . As the support roll 3 and the upper leveler roll 4, it is preferable to use a ceramic roll sprayed with a ceramic so that a pickup flaw, which is a sintering phenomenon due to the contact between the roll and the steel plate P, does not occur.

In the present embodiment, the upper leveler roll 4
By setting the amount of reduction of the above to about 7 mm or more, the occurrence of slip between the upper leveler roll 4 and the steel plate P can be suppressed, and the upper leveler roll 4 can be stably brought into an idling state. Therefore, the C-warp shape generated by the floater F can be corrected by the correction device 2 installed on the downstream side from the heating zone HF. Further, the C warpage that occurs when the line tension of the steel sheet P is increased in order to correct the rolled shape defect portion of the original sheet can also be corrected by the straightening device 2. As a result, a flat steel plate P can be obtained. Since the C-warp shape of the plate width of the steel plate P generated by the floater F is largely curved when the line tension is large, it is necessary to increase the reduction amount of the upper leveler roll 4. For example, the line tension is about 0.7
In the case of kg / mm ² , the reduction amount needs to be about 20 mm or more.

The location where the straightening device 2 is installed is not particularly limited so long as it can straighten the C-warp shape of the width of the steel sheet P generated by the floater F without affecting the characteristics of the steel sheet P. But not limited to
For example, the endurance temperature of the upper leveler roll 4 is 750
℃ or less, and the amount of reduction of the upper leveler roll 4 is 20 mm
When the elongation of the steel sheet is 0.2%, the temperature of the steel sheet is 65%.
If the temperature is 0 ° C. or higher, it is provided between the inlet side CFa and the outlet side CFb of the cooling section CF due to the temperature drop (heat cycle) shown in FIG. In this embodiment,
The straightening device 2 is installed on the outlet side CFb of the cooling zone CF.

If a large amount of reduction (for example, about 30 to 50 mm) is applied in order to correct a large amount of C warp by the upper leveler roll 4 which is the correction device 2,
There is a case where a curved shape in the traveling direction, that is, a so-called L warp shape is generated in the steel plate P. In consideration of such a case, in the present embodiment, as shown in FIGS. 2 to 3 and 5, the lower leveler roll 30 installed below the pass line L on the downstream side of the straightening device 2 is provided. I have it. In the present invention, the lower leveler roll 30 is, so to speak, an L warp straightening roll. Like the upper leveler roll 4, the lower leveler roll 30 has both shaft end portions 31 thereof inserted into the long holes 32 formed in the side wall 6, and
It is supported by a bearing 34 fixed to the side portion of the slider 33. The slider 33 is inserted into a guide member 35 attached to the side wall 6, and can be moved up and down by a worm jack 16 which is an elevating means A connected to a lower portion and a motor 17. The roll diameter of the lower leveler roll 30 is for correcting the L-warp of the steel sheet, and is therefore about 200 to 400 mm, preferably about 250 to 350 mm. As the lower leveler roll 30, it is preferable to use a ceramic roll, like the upper leveler roll 4. By setting the amount of reduction of the lower leveler roll 30 to 30 to 80 mm, the L-warp shape of the steel plate P can be corrected and the steel plate P can be made flatter.

The floating continuous annealing furnace may be temporarily stopped due to a setup change or trouble due to a change in steel type, and the straightening device may not be used.
In such a case, the upper leveler roll 4 and the lower leveler roll 30 may bend due to the temperature in the furnace and the weight of the rolls, and there is a possibility that residual bending damage may occur in each roll.
In the present embodiment, in order to prevent bending damage of the upper leveler roll 4 and the lower leveler roll 30, a one-way rotation clutch 40 is attached to the shaft end portions 11 and 31 of the upper leveler roll 4 and the lower leveler roll 30. ,
It is preferable to rotate each roll in the traveling direction of the steel plate P at a peripheral speed of about 100 m / min so that the speed difference is small when the rolls are brought close to the steel plate traveling speed by the driving means B, for example, when they contact the traveling steel plate. This is because pickup is likely to occur when the speed difference is large. When the correction device 2 is used, the drive means B is stopped. This allows
The upper leveler roll 4 and the lower leveler roll 30 are rotated by the contact friction with the steel plate P. As the one-way rotation clutch 40, a cam clutch using a cam or a ball clutch using a ball can be used. Further, as the driving means B, a sprocket 41 attached to the shaft end portions 11 and 31, and a sprocket 42
It is possible to use a motor having a motor 43 and a chain 44 wound around each sprocket 41, 42, but the present invention is not limited to this, and a gear is used instead of each sprocket. In addition, a timing belt can be used instead of the chain.

Next, another embodiment of the present invention will be described. As shown in FIG. 6, the steel sheet has different annealing conditions (temperature × sheet passing speed) depending on the steel type. Therefore, it is not possible to deal with the steel sheet of each steel type by only installing one of the straightening devices. C Variations in the correction of the warp shape are likely to occur. For this reason, it is desirable to install at least a straightening device for low-temperature processed materials having a low plate temperature immediately after the heating zone and a straightening device for high-temperature processed materials having a high plate temperature at a position away from the heating zone. .

In the present embodiment, the straightening device 2 of the above embodiment is installed in the ambient gas seal portion 50 of the inlet side CFa of the cooling zone CF and the outlet side CFb.

Then, the plate passing speed or the set furnace temperature of the heating zone HF is controlled so that the optimum plate temperature region T for correcting the C-warp shape of the steel plate P is 650 to 750 ° C.
Two corrective devices 2 are used properly. Therefore, the steel plate of each steel type can be flattened.

Incidentally, by equipping the straightening device 2 with the lower leveler roll 30, the C level is the same as in the above embodiment.
A flat steel plate can be obtained by correcting the warped shape and the L-warped shape.

[0028]

As described above, according to the present invention,
Even if the elongation rate of the steel sheet changes due to the change in the temperature of the steel sheet, the upper leveler roll and the lower leveler roll are in a non-driving state, that is, in an idling state so as to rotate due to friction with the steel sheet. For this reason, since the rotation speed of each roll is synchronized with the strip passing speed of the steel sheet, pick-up or oyster flaws are less likely to occur on each roll, and the frequency of removal work can be reduced, and the steel sheet is also flawed. It becomes difficult to attach.

Further, by attaching a one-way rotating clutch to the shaft end portions of the upper leveler roll and the lower leveler roll, it is possible to rotate the rolls at a low speed and prevent the bending damage of the rolls when the rolls are not used.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a floating type continuous annealing furnace equipped with a straightening device of the present invention.

FIG. 2 is a side view showing an embodiment of a correction device of the present invention.

FIG. 3 is a sectional view taken along line I-I.

FIG. 4 is a sectional view taken along line II-II.

FIG. 5 is a schematic diagram showing correction of a warp shape of a steel plate.

FIG. 6 is an explanatory diagram showing a temperature drop in a cooling zone.

FIG. 7 is an explanatory view showing a conventional floating type continuous annealing furnace.

FIG. 8 is an explanatory diagram showing C warpage of a steel plate.

[Explanation of symbols]

1 Outlet of furnace 2 Straightening device 3 support rolls 4 Upper leveler roll 30 Lower leveler roll 50 Atmosphere gas seal A lifting means NOF pretropical zone HF heating zone CF cooling zone CFa Cooling zone entry side CFb Cooling zone exit side

Continuation of the front page (56) Reference JP-A-5-76935 (JP, A) JP-A-6-304657 (JP, A) JP-A-61-20622 (JP, A) JP-A-3-86320 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21D 1/05 C21D 9/56 101

Claims (3)

(57) [Claims] 1. A straightening device installed to straighten the shape of a steel sheet in a continuous annealing furnace, comprising a support roll,
An upper leveler roll for pressing the steel plate from above, an elevating means for elevating the upper leveler roll, and the upper part
It is installed on the downstream side of the leveler roll and presses the steel plate from below.
Lower leveler roll and the lower leveler roll
The upper leveler roll is composed of an elevating means for lowering.
Has a roll diameter of 100 to 200 mm.
While the Raroru is pressurized steel, when the upper leveler rolls, which are rotatable by a non-driving Tomo
In addition, the roll diameter of the lower leveler roll is 200-40.
0 mm, the lower leveler roll presses the steel plate
While the lower leveler roll is rotating,
A straightening device characterized by being freely rotatable . 2. The correction device according to claim 1, further comprising a one-way rotation clutch attached to an axial end portion of the upper leveler roll and a drive unit connected to the one-way rotation clutch. 3. A one-way rotation clutch that are respectively attached to the axial end portion of the upper leveler shaft end portion and the lower leveling rolls of the roll, comprising a drive means connected to said one-way rotation clutch according to claim 1, wherein Straightening device.