JP2003290829A - Roller leveling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller leveling method with a roller leveler for stably performing flattening of the camber and wavy shape of a material to be leveled. <P>SOLUTION: The amount of pushing-in of a roller when leveling the part on at least one of front and rear end parts of the material to be leveled is taken as larger than the amount of pushing-in of the roller when leveling the steady part of the material to be leveled. Preferably, it is preferable to take the amount of pushing-in of the roller in the tip and rear end parts as 1.5 times the amount of pushing-in of the roller in the steady part. Then, the effect of leveling is stably obtained over the entire length by respectively adopting the proper pushing-in conditions of the roller. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention arranges a plurality of rolls in a zigzag pattern in the vertical direction and repeatedly bends the material to be bent between the rolls to flatten the warp of the material to be straightened or to corrugate it. The present invention relates to a roller straightening method using a roller leveler for straightening a shape.

[0002]

2. Description of the Related Art A roller leveler is used to flatten a warp generated in a rolling process or a cooling process of a plate material, a shape material, a pipe material, a wire material or the like, or to correct a wave shape. In the roller leveler, the pressing amount of a plurality of rolls arranged in a zigzag pattern on the upper and lower sides is controlled, and a material to be straightened is passed between the upper and lower rolls to perform roller straightening. The straightening action of the roller leveler is to repeatedly bend the material to be straightened to flatten the material to be straightened, or to give a desired warp or corrugation. Each roll position of the roller leveler is
Determined experimentally, empirically, or theoretically based on the dimensions of the material to be straightened, material constants, warpage, corrugations, roll diameter of roller levelers, roll pitch, rigidity, flatness required for the straightened material, etc. It is set so that the amount of roll indentation required to exert the straightening effect can be obtained. here,
The roll indentation amount is obtained by subtracting the distance between the apex of the roll and the straight line connecting the apex of the front and rear rolls of the roll from the thickness of the material to be straightened, and the apex of the roll and the front and rear rolls of the roll. When the distance from the straight line connecting the vertices of is shorter than the thickness of the material to be straightened, it is regarded as positive. Further, here, unless otherwise specified, each roll pushing amount means an actual roll pushing amount at the time of straightening, in which roll displacement or rattling due to elastic deformation of the roller leveler caused by the straightening reaction force is corrected.

At this time, since the straightening load for straightening the front and rear ends of the material to be straightened is generally smaller than the straightening load for straightening the steady portion of the material to be straightened, the elasticity of the roller leveler caused by the straightening reaction force is generated. The roll displacement due to the deformation is smaller when the front and rear ends of the material to be straightened are straightened than when the steady portion of the material to be straightened is straightened.
Conventionally, as disclosed in Japanese Unexamined Patent Publication No. 62-142024, a roll displacement detector is provided to measure each roll displacement amount and each roll position is compensated for. Is controlled to correct the set reduction amount.

[0004]

However, as described above, each roll pushing amount is set so that the roll pushing amount is constant over the entire length regardless of the steady portion, front and rear end portions (unsteady portion) of the material to be straightened. Even if controlled straightening is performed, there is a problem that a sufficient straightening effect cannot be obtained over the entire length of the material to be straightened. This means that even if the front and rear ends of the material to be straightened, which are less restrained on the entry / exit side, are straightened with the same amount of roll pushing as when straightening the steady part of the material to be straightened, the bending applied to the material to be straightened Is smaller than the bending given to the steady part of the material to be straightened, that is, the desired bending is not given. Therefore, under the present circumstances, an effective technique for making the correction of the front and rear end portions of the material to be straightened and the steady portion compatible in an appropriate state has not yet been established. The present invention has been made in view of the above-mentioned problems of the prior art, and a stable and sufficient straightening effect can be obtained over the entire length of the material to be straightened regardless of the steady portion and the non-steady portion of the straightened material. An object is to provide a roller straightening method.

[0005]

The gist of the present invention for achieving the above object is as follows. (1) Roller straightening by a roller leveler that flattens the warp of the material to be straightened or corrects the wave shape by arranging a plurality of rolls in a zigzag pattern on the upper and lower sides and repeatedly bending the material to be straightened between the rolls. In the method
A roller straightening method, characterized in that a roll pushing amount when straightening at least one of front and rear end portions of a straightened material is made larger than a roll pushing amount when straightening a steady portion of the straightening material. (2) The amount of roll indentation for any straightening roll is
The timing for making the roll push-in amount at the time of straightening the steady part of the material to be straightened is at the latest when the leading edge of the material to be straightened bites into the roller leveler, and at the latest, the leading edge of the material to be straightened is 3 times the roll. The roller straightening method according to (1), characterized in that it is before the moment of being bitten into a roll located downstream of the main roller. (3) The roll pushing amount for any straightening roll is
The timing of changing from the roll push-in amount when straightening the steady portion of the material to be straightened is before the rear end of the material to be straight slips through the roller leveler, and at the earliest the rear end of the material to be straightened The roller straightening method according to (1) or (2), characterized in that it is after the moment when the rolls on the upstream side of the three rolls pass through. (4) When straightening at least one of the front and rear ends of the material to be straightened, the roll pushing amount for an arbitrary straightening roll is 1.5 times or less the roll pushing amount when straightening the steady portion of the straightened material. (1) to (3) characterized in that
The roller straightening method according to any one of 1.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, examples of preferred embodiments of the present invention will be described. First, based on the dimensions of the material to be straightened, material constant, warpage, corrugation, roll diameter of roller leveler, roll pitch, rigidity, flatness required for the straightened material, etc.・ Find the roll push-in amount and the range to change the roll push-in amount required to perform roller straightening for each steady part. At this time, the roll pushing amount of the front and rear end portions of the material to be straightened is made larger than the roll pushing amount when straightening the steady portion of the material to be straightened.

Before the material to be straightened bites into the roller leveler, first, each roll pushing amount is set to a roll pushing amount necessary for straightening the most distal end portion of the material to be straightened. For each arbitrary roll, after the leading edge of the material to be straightened bites into the roll, the longitudinal distance between the leading edge of the material to be straightened and the roll axis becomes a range length that changes the roll pushing amount. At this time, the roll push-in position is changed so that the push-in amount of the roll becomes the push-in amount necessary for straightening the steady part of the material to be straightened. further,
From the time when the distance in the longitudinal direction between the rearmost end of the material to be straightened and the roll axis becomes a range length for changing the roll pushing amount, when the rearmost end of the material to be straightened passes through the roll, The roll pushing position is changed so that the pushing amount of the roll becomes the pushing amount necessary for straightening the rearmost end portion of the material to be straightened. In the present invention, the roll pressing amount may be changed at the above-mentioned timing in at least one of the front and rear ends of the material to be straightened, but if possible, it is desirable to apply it to both the front and rear end portions of the same material to be straightened. .

From various numerical and experimental studies, the length of the unsteady deformation region during roller straightening is within 3 times the roll half pitch (the longitudinal distance between adjacent upper and lower roll shaft cores) at both the front and rear ends. It turned out to be Therefore, the range length for changing the roll indentation is such that, for any given roll, at the latest, the tip of the material to be straightened is caught by three rolls (not counting the roll) downstream from the roll. It is preferable to set it before the moment when the roll is inserted, and after the moment when the trailing end of the material to be straightened passes through the roll that is three upstream from the roll (counted without the roll) at the earliest. Further, it is essential that the roll push-in amount with respect to the frontmost rear end portion of the material to be straightened is larger than the roll push-in amount with respect to the steady portion of the straightened material, but the push-in amount of the unsteady portion is one of the push-in amount of the steady portion. It is preferably not more than 5 times. If the pushing amount exceeds 1.5 times, the bending given to the unsteady part of the material to be straightened becomes excessive, and the straightening effect is rather deteriorated.

In this way, the roll positions are controlled so as to give the optimum roll pushing amounts to the front and rear end portions and the stationary portion of the material to be straightened, whereby the entire length of the material to be straightened is sufficiently controlled. Because you can give a bend
A sufficient correction effect can be obtained. It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

[0010]

EXAMPLES [Example 1] Using the method of the present invention, a plate thickness of 1
Roller straightening was performed using a normal steel plate of 5.0 mm and a plate width of 3000 mm as a material to be straightened. FIG. 1 is a schematic side view of the roller leveler used in this example. This roller leveler has a configuration in which a total of 11 rolls 1 to 11 of 5 upper rolls and 6 lower rolls are alternately arranged in a staggered manner, and the lower roll group 12
Is fixed in its position and each upper roll 2, 4, 6, 8, 1
By controlling the pushing amount of the roll pushing devices 14 to 18 between the upper rolls 2, 4, 6, 8 and 10, the upper rolls 2, 4, 6, 8 and 10 can be pushed individually and independently. There is. Also, it is possible to measure each roll load during straightening by a load cell (not shown), and each roll displacement is calculated from each roll load and the rigidity of the roller leveler that is grasped in advance, so as to offset this. By controlling each roll pushing device, the desired roll pushing amount can be obtained.
The roller leveler has a roll diameter of 280 mm and a roll half pitch of 150 mm.

The amount of pushing in each roll required for straightening the roller of the material to be straightened is as follows:
The results were obtained as shown in Table 1. In addition, the length of the unsteady deformation zone at the front and rear ends is 2 roll half pitch of the roller leveler.
It was expected to double.

[0012]

[Table 1]

FIG. 2 shows a time change (set value) of each roll pressing amount under the present conditions. The reason why the roll pushing amount is changed in this way will be described by taking the # 2 roll pushing device 14 as an example. First, after setting the # 2 roll pushing device 14 so that the pushing amount of the # 2 roll is 5.4 mm, the material to be straightened is bitten into the roller leveler. The material to be straightened bites in order from the # 1 roll, but at the same time, the leading edge position of the material to be straightened is tracked by detecting the rotational speed of each roll drive motor of the roller leveler. Under these conditions, the length of the unsteady deformation zone at the tip of the material to be straightened was expected to be twice the half pitch of the roll, so at the latest when the material to be straightened bites into the # 4 roll, the pushing amount of the # 2 roll is It is necessary to keep the push-in amount of the stationary part to 4.6 mm. Therefore, immediately before the leading edge of the material to be straightened bites into the # 4 roll, the # 2 roll pushing device is started to open, and when the leading edge of the material to be straightened is bitten into the # 4 roll, the # 2 roll is rolled. # So that the pushing amount is 4.6 mm
The two-roll pushing device 14 is controlled.

As described above, by sequentially operating the roll pushing devices # 4, # 6, and # 8 while tracking the leading edge position of the material to be straightened, the front end of the material to be straightened also has a constant portion. The same correction effect as can be obtained. Also,
With respect to the rear end portion of the material to be corrected, the same correction effect as that of the stationary portion can be obtained by the same method as described above. In the case of the rear end portion, the correction effect equivalent to that of the stationary portion can be obtained by sequentially operating the roll pushing devices # 4, # 6, # 8, and # 10. In this way, by controlling the roll position and performing the roller straightening so that the optimum amount of roll indentation for each part is obtained with respect to the leading and trailing end portions and the steady portion of the material to be straightened, stable operation is achieved over the entire length. It was possible to obtain a straightening effect.

FIG. 3 shows a case where straightening is performed by this method and a case where each roll is fixed to a roll pushing amount when straightening a constant part of a material to be straightened and a full length roller straightening is carried out as a comparative example. The flatness inspection pass rate is shown. The flatness was determined by measuring the warp height and wave height of the material to be straightened with a flatness meter provided on the rear surface of the roller leveler. It can be seen that the present invention has a higher pass rate than the comparative example and a sufficient correction effect is obtained.

In this embodiment, the hydraulic pushing devices are used as the roll pushing devices 14 to 18, but if the roll pushing amount can be changed even during the passage of the material to be straightened. , But is not limited to this.
Further, in the present embodiment, the position of the material to be straightened was tracked by obtaining the number of rotations of the leveling roll from the number of rotations of the roller leveler drive motor, but for example, a method of determining by the load cell load provided in each roll, any A method of making a judgment by a plate detection sensor installed on each roll output side or a method of making a visual judgment by an operator or the like may be adopted, and this method does not limit the position tracking method of the material to be straightened. . Furthermore, although each roll pushing amount is changed linearly with respect to time, a method of changing it by using a higher-order function or a trigonometric function may be adopted, and this method is a method of changing each roll pushing amount. Is not limited to this.

[Embodiment 2] This embodiment is a suitable method for a roller leveler in which each roll position cannot be set independently. FIG. 4 is a schematic side view of the roller leveler used in this example. This roller leveler has 5 upper rolls,
The lower roll group 12 is composed of a total of 11 rolls 1 to 11 of the six lower rolls, and the inlet side pushing device 19 and the outlet side pushing device 20 are operated with respect to the lower roll group 12 so that the upper roll group 13 It is possible to tilt and push. Since a hydraulic pushing device is used here as the entrance side roll pushing device 19 and the exit side roll pushing device 20, it is possible to change the roll pushing amount even during the passage of the material to be straightened. ing. In addition, it is possible to measure the loading / unloading side load during straightening with a load cell (not shown). By controlling the entrance-side roll pushing device 19 and the exit-side roll pushing device 20, desired roll pushing amounts can be obtained.

Using this method, a plate thickness of 15.0 mm and a plate width of 3
Roller straightening was performed using a 000 mm ordinary steel plate as a material to be straightened. Similar to the case of the first embodiment, the roll pressing amounts desired for the roller straightening of the material to be straightened are obtained as shown in Table 1 for the leading edge portion, the stationary portion, and the rearmost portion. . The length of the unsteady deformation region at the front and rear ends is also expected to be twice the roll half pitch of the roller leveler. However, in the case of the present embodiment, the roll pushing device is only the entry side pushing device 19 and the exit side pushing device 20 of the upper roll group, and it is not possible to push each upper roll individually. In view of this, in this embodiment, the amount of pushing-in and pushing-out that each roll pushing amount is as close as possible to the desired value shown in Table 1 was obtained by the least square method and adopted.

FIG. 5 shows a time change (set value) of each roll pushing amount under the present conditions. In the case of this example, the entrance and exit roll pushing devices 19 and 20 are simply operated. In this way, by controlling the roll position and performing the roller straightening so that the optimum amount of roll indentation for each part is obtained with respect to the leading and trailing end portions and the steady portion of the material to be straightened, stable operation is achieved over the entire length. It was possible to obtain a straightening effect.

FIG. 6 shows the flatness inspection when the straightening is carried out by the present method and as a comparative example, when the straight portion of the material to be straightened is fixed to the amount of roll pushing and straightening is performed. Indicates the pass rate. Similar to Example 1, the flatness was determined by measuring the warp height and wave height of the material to be straightened with a flatness meter provided on the rear surface of the roller leveler. It can be seen that the present invention has a higher pass rate than the comparative example and a sufficient correction effect is obtained.

[0021]

According to the above-described method of the present invention, the roll pushing amount when straightening the front and rear ends of the material to be straightened is made larger than the roll pushing amount when straightening the steady portion of the material to be straightened. Thus, a sufficient straightening effect can be stably obtained over the entire length of the material to be straightened. As a result, the re-correction rate is lowered, so that time loss and energy loss can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a side view showing an outline of a roller leveler used in a first embodiment of the present invention.

FIG. 2 is a diagram showing a change over time in the amount of pushing each roll used in Example 1 of the present invention.

FIG. 3 is a graph showing flatness passing rates of materials to be straightened in Example 1 of the present invention and Comparative Example.

FIG. 4 is a side view showing the outline of a roller leveler used in Example 2 of the present invention.

FIG. 5 is a diagram showing a change over time in the amount of pushing each roll used in Example 2 of the present invention.

FIG. 6 is a graph showing flatness passing rates of materials to be straightened in Example 2 of the present invention and Comparative Example.

[Explanation of symbols]

1 # 1 roll (lower roll) 2 # 2 roll (upper roll) 3 # 3 roll (lower roll) 4 # 4 roll (upper roll) 5 # 5 roll (lower roll) 6 # 6 roll (upper roll) 7 # 7 rolls (lower roll) 8 # 8 rolls (upper roll) 9 # 9 rolls (lower roll) 10 # 10 rolls (upper roll) 11 # 11 rolls (lower roll) 12 upper roll groups 13 lower roll groups 14 # 2 rolls Pushing device 15 # 4 roll pushing device 16 # 6 roll pushing device 17 # 8 roll pushing device 18 # 10 roll pushing device 19 entry side roll pushing device 20 exit side roll pushing device 21 housing

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeru Ogawa             20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel shares             Company Technology Development Division F-term (reference) 4E003 AA01 BA12

Claims (4)

[Claims] 1. A roller leveler for arranging a plurality of rolls in a zigzag pattern vertically and repeatedly bending the material to be corrected between the rolls to flatten the warp of the material to be corrected or to correct the wave shape. In the roller straightening method, the roll pushing amount when straightening at least one of the front and rear end portions of the straightened material is larger than the roll pushing amount when straightening the steady portion of the straightening material. Roller straightening method. 2. The timing at which the roll push-in amount for an arbitrary straightening roll is made to coincide with the roll push-in amount when straightening a steady part of a straightened material is such that the most distal end of the straightened material bites into the roller leveler. The roller straightening method according to claim 1, characterized in that, at the latest, at the latest, before the moment when the most distal end portion of the material to be straightened is caught in the roll located three downstream of the roll. 3. The timing of changing the amount of roll indentation for an arbitrary straightening roll from the amount of roll indentation when straightening a steady portion of the material to be straightened is such that the rearmost end of the material to be straightened slips past the roller leveler. The roller straightening method according to claim 1 or 2, characterized in that it is before, at the earliest, after the moment when the rearmost end portion of the material to be straightened passes through the roll located three upstream of the roll. 4. When the at least one of the front and rear ends of the material to be straightened is straightened, the roll push-in amount for an arbitrary straightening roll is 1.5 times the roll push-in amount when straightening a steady portion of the straightened material. The roller straightening method according to any one of claims 1 to 3, wherein the number of times is not more than twice.