KR20180073210A - Apparatus for correcting sheet material and method of fabricating sheet material - Google Patents

Abstract

The present invention relates to an apparatus to correct a sheet material and a sheet material manufacturing method using the same. According to one embodiment of the present invention, the apparatus to correct a sheet material comprises: a frame having inlet and outlet sides; a plurality of working rolls mounted on the frame, and arranged on upper and lower parts of the sheet material in a transfer direction of the sheet material to be in contact with the sheet material; and a cylinder moving the frame to adjust an intermesh of the working rolls. The working rolls are divided into a first group disposed on the inlet side, a second group disposed on the outlet side, and a third groove disposed between the first and second groups. The working rolls of the first group are arranged at first intervals, a part of the working rolls close to the first group among the working rolls of the third group are arranged at second intervals smaller than the first interval, and the remaining other working rolls among the working rolls of the third group are arranged at intervals gradually increased apart from the inlet side.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate material calibrating apparatus and a plate material manufacturing method using the plate material calibrating apparatus,

The present invention relates to a sheet material correcting apparatus and a sheet material manufacturing method using the same.

Hot rolled / cold rolled / surface treated products manufactured by steel mills are wound and stored in the form of coils. The coil thus stored, or the sheet material cut to a specific length of the coil, is cut into a blank of a specific shape, and the cut blank is processed from the part to the product. During this series of processes, defects in shape may occur in the product.

Typically, to alleviate such defects, a calibrating process may be performed using a plate material calibrating device such as an uncoiling process, a sheet process, and a roller leveler before and after the blanking process.

However, since a plate material having a thin thickness or a very high yield strength has a strong tendency to restoring elasticity by springback, a conventional sheet material correcting apparatus is not suitable for a sheet material, Occasionally. Particularly, there has been a problem in that it is difficult to accurately correct the shape of a recently developed high strength plate material in a conventional sheet material correcting apparatus.

Korean Laid-Open Publication No. 2014-0084661

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet material correcting apparatus capable of effectively ensuring a flatness correction of a plate material difficult to be calibrated, such as a thin article and / or a high strength plate material.

One of the objects of the present invention is to provide a method of manufacturing a plate material which can effectively ensure flatness correction of a plate material which is difficult to correct such as a natural and / or high-strength plate material.

According to an embodiment of the present invention, there is provided a method of manufacturing a workpiece, comprising: a frame having an inlet side and an outlet side; a plurality of work rolls mounted on the frame and arranged respectively at upper and lower portions of the plate along the feeding direction of the plate to contact the plate; And a control section for controlling intermeshing of the plurality of work rolls and the interval of the adjacent work rolls, wherein the plurality of work rolls are divided into a first group positioned at the entrance side, a second group positioned at the exit side, Wherein the control unit adjusts the first group of work rolls to a first interval and the second group of work rolls adjacent to the first group to a third group positioned between the first group and the third group, And the other work rolls of the third group of work rolls are adjusted to be spaced apart from each other as they move away from the entrance side.

In one example, the first group of work rolls is the first three work rolls positioned at the entrance, and the two adjacent work rolls located at the top or bottom are arranged at the first interval.

In one example, the second group of work rolls is of the same number as the first group of work rolls and may be arranged at substantially the same interval as the first gap.

In one example, the first gap may be in the range of 10-30% diameter of the working roll.

In one example, the spacing of the remaining work rolls of the third group of work rolls may decrease linearly away from the entry side.

In one example, the second gap L is set by the following equation to have an effective radius of curvature rho equal to or smaller than the effective radius of curvature applied to the first group of work rolls,

Here, IM may be an intermesh of the second group of work rolls.

In one example, a backup roll is disposed between the plurality of work rolls and the frame, and the backup rolls can have different diameters.

According to an embodiment of the present invention, there is provided a sheet material straightening apparatus comprising: a sheet material calibrating device including a frame having an inlet side and an outlet side, and a plurality of work rolls arranged respectively at upper and lower portions of a plate material mounted on the frame, Calculating an intermesh of the work rolls of the first group located at the entrance side based on the calculated intermeshes and setting an intermesh of the work rolls of the first group positioned at the entrance side by the calculated intermeshes, Calculating a radius of curvature of the first group of working rolls; calculating a radius of curvature of the third group of working rolls located between the first and second groups; Calculating the spacing of the third group of work rolls so as to have substantially the same effective radius of curvature, adjusting the position of the work rolls of the third group at the calculated intervals, And transferring the sheet material under the intermeshing condition.

In one example, after the conveying step, measuring the defective shape of the conveyed sheet material to determine whether or not it has reached a target level, and if the target level is not reached, increasing the target burning ratio stepwise And repeatedly performing the steps of FIG.

In one example, setting the intermesh of the second group of work rolls may include setting an intermesh of the second group of work rolls within a 10% error in thickness of the plate material.

In one example, the work rolls of the first and second groups are three work rolls positioned on the inboard side and the outboard side, respectively, and the intervals of the first and second groups of work rolls are two adjacent workpieces Roll distance.

In one example, three work rolls adjacent to the first group of work rolls of the third group have an interval smaller than the interval of the first group, and the other work rolls of the third group of work rolls As shown in FIG.

According to the present embodiment, in performing the shape defect correction work of the plate material, the gap between the rolls is variably controlled so that plastic deformation is applied to the plate material, whereby defective shape of the calibration plate can be solved. In particular, the article and / or the high strength plate can be effectively calibrated.

1 is a schematic block diagram showing a sheet material correcting apparatus according to an embodiment of the present invention.
Fig. 2 is a schematic view showing a roll arrangement of the sheet material correcting apparatus shown in Fig. 1. Fig.
3A to 3E are schematic diagrams illustrating curvature types to be subjected to plate material correction.
4A to 4C are schematic diagrams for explaining the interval between the intermesh and the roll, which represent the relative positions of the adjacent rolls.
5 is a schematic view for explaining the firing ratio for the plate material.
6 is a schematic diagram for explaining the effective radius of curvature to which the plate material is applied.
7 is a flowchart illustrating a method of calibrating a sheet material according to an embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments may be modified in other forms or various embodiments may be combined with each other, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments are provided so that those skilled in the art can more fully understand the present invention. For example, the shapes and sizes of the elements in the drawings may be exaggerated for clarity of description, and the elements denoted by the same reference numerals in the drawings are the same elements. Also, in this specification, terms such as "upper", "upper surface", "lower", "lower surface", "side surface" and the like are based on the drawings and may actually vary depending on the direction in which the devices are arranged.

The term " one example " used in this specification does not mean the same embodiment, but is provided to emphasize and describe different unique features. However, the embodiments presented in the following description do not exclude that they are implemented in combination with the features of other embodiments. For example, although the matters described in the specific embodiments are not described in the other embodiments, they may be understood as descriptions related to other embodiments unless otherwise described or contradicted by those in other embodiments.

Fig. 1 is a schematic block diagram showing a sheet material correcting apparatus according to an embodiment of the present invention, and Fig. 2 is a schematic diagram showing a roll arrangement of the sheet material correcting apparatus (box part) shown in Fig.

1, a sheet material correcting apparatus 100 according to the present embodiment includes a frame 111 having an inlet side and an outlet side, a plurality of work rolls 115a and 115b mounted on the frame 111, And a control unit 120 for controlling the intermeshing of the plurality of work rolls 115a and 115b and the interval of the adjacent work rolls.

The sheet material correcting apparatus 100 may further include cylinders 121a and 121b equipped with a frame 111 and adapted to adjust an intermesh and pinch rolls 150a and 150b respectively adjacent to an inlet and an outlet.

The sheet material 200 can be a coil, a sheet material cut to a specific length in the coil, or a blank cut to a specific shape in the sheet material. The plurality of work rolls 115 are arranged to contact the plate 200 along the conveying direction of the plate 200 and are disposed on the lower and upper sides of the plate 200, And a work roll 115b.

The sheet material 200 can be transferred between the upper work roll 115b and the lower work roll 115a. If the difference between the heights of the lower work rolls 115a and the upper work rolls 115b of the plurality of work rolls 115 is less than or equal to the thickness of the plate material 200, Can be calibrated by being pressed by the work roll 115.

The relative positions of the adjacent work rolls 115a and 115b among the plurality of work rolls 115 may be defined as intermesh. This will be described later in detail with reference to Figs. 4A to 4C.

When the intermeshing of adjacent rolls 115a and 115b (see FIG. 4) is sequentially performed along the conveying direction of the plate material 200 and then the plate material is passed, the plate material 200 is repeatedly subjected to the bending-expansion deformation, The degree of correction of the defective shape is determined according to the plastic deformation amount received. The degree of correction of the shape defects existing in the plate member 200 may vary depending on the amount of plastic deformation of the plate member 200. This will be described later in detail with reference to Figs. 3A to 3E.

Such an intermesh may be adjusted by the control unit 120. [ That is, it can be adjusted by receiving the signal S1 transmitted from the control unit 120 and driving the cylinders 121a and 121b mounted on the frame 111. [ For example, when the controller 120 applies different forces to the plurality of cylinders 111 as shown in FIG. 2, the intermeshing of the input work rolls is adjusted to be smaller than the intermesh of the output work rolls .

On the other hand, the positions of the plurality of work rolls 115 may be fixed by the backup roll 112 and the roll frame 111. When the plate 200 is calibrated by a plurality of work rolls 115, the plurality of work rolls 115 may also be subjected to a reaction force, wherein the backup rolls 112 and the roll frame 111 So that the plurality of work rolls 115 can be fixed. Specifically, the backup roll 112 can absorb the rotational force of the plurality of work rolls 115, and the roll frame 111 can absorb the forces acting on the upper and lower sides of the plurality of work rolls 115.

In this embodiment, the interval of the work rolls 115 can be adjusted by the control unit 120. [ For example, the interval of the work rolls 115 can be adjusted by transmitting the second signal S2 generated by the control unit 120 to the backup rolls 112. [ As in the present embodiment, the back-up rolls 112 can have different diameters, and the intervals of the work rolls 115 can be adjusted by moving the back-up rolls 112 having different diameters up and down.

Referring to FIG. 2, the plurality of work rolls 115 includes a first group I positioned at the entrance side, a second group II located at the exit side, and first and second groups I, And a third group (III) located between the first group and the second group.

The control unit 120 may adjust the work rolls of the first group I to the first interval L0. The work rolls of the first group (I) are the first three work rolls located at the mouth side (see Figs. 4A to 4C), and the two adjacent work rolls 115a located at the upper or lower part are positioned at the first gap L0 ). ≪ / RTI > For example, the first gap L0 may range from 10 to 30% of the diameter D of the work roll.

The work rolls of the second group II are the same number (for example, three) as the work rolls of the first group I and are arranged at an interval L0 substantially equal to the first intervals L0 .

It is possible to adjust some work rolls adjacent to the first group I of the work rolls of the third group III to a second gap L1 smaller than the first gap L1. The second gap L1 may be set to have an effective radius of curvature equal to or smaller than the effective radius of curvature rho applied to the work roll of the first group I. Specifically, the second gap L1 can be calculated by applying the same effective radius of curvature as the intermeshed applied to the work roll using Equation (2) below. This will be described later in detail with reference to the following Equation 2 and the flowchart shown in FIG.

And the other work rolls of the work rolls of the third group (III) are arranged to be adjusted to be spaced apart from each other (L2 < L3 < The intervals (L2 < L3 < ...) of the other work rolls can be linearly increased. If the interval between the rolls is changed linearly to the end, the nonlinearity due to the bending deformation of the plate material can be minimized, which can be advantageous for the correction of the shape, and it is possible to reduce the load on the equipment during operation.

Figs. 3A to 3E are schematic views illustrating curvature types to be subjected to plate material correction, and represent examples of typical shape defects.

As illustrated in Figs. 3A and 3B, each of the plate members 200a and 200b may have a curved L-curvature in the winding longitudinal direction and a curved C-curvature curved in the width direction. Referring to FIG. 3C, the plate member 200c may have an edge wave having a wave at a widthwise edge thereof. On the other hand, the plate member 200d illustrated in FIG. 3D has a center buckle having a convex shape in the widthwise center, and the plate member 200e illustrated in FIG. 3E can have a camber generated by the non-uniform residual stress in the width direction.

4A to 4C are schematic views for explaining an intermesh showing the relative positions of neighboring work rolls.

The intermesh has a negative value when the upper roll 115b is positioned below the reference line on the basis of the case where the two adjacent lower rolls 115a are on the same line and the upper roll 115b is positioned above the reference line The positive value is used. The distance between the rolls means the distance D between adjacent rolls located below or above the plate material 200. [

4A, the intermesh, which is the height difference between the two lower rolls 115a and the upper rolls 115b of the plurality of work rolls, may be 0 (IM = 0). Referring to FIG. 4B, the intermesh, which is the difference in height between the lower roll 115a and the upper roll 115b, may be -a (IM = -a). Referring to FIG. 4C, the intermesh of the height difference between the lower roll 115a and the second roll 115b among the plurality of work rolls may be + b (IM = + b).

The intermeshes of the inlet side, i. E. The first group (e.g., the relative height between the first two rolls) and the outlet, i. E. The second group (the relative height between the last two rolls) are determined by the operator's theoretical or empirical criteria. Since all work rolls are constrained to a single roll frame, the intermesh of the rolls of the third group, located in the middle, can be determined by a linear distribution of both end values.

5 is a schematic view for explaining the firing ratio for the plate material.

Referring to FIG. 5, the plate 200 has a thickness of t and can be divided into a plastic region and an elastic region. Plastic Fraction (PF) of the plate material 200 is defined as a ratio of a plastic deformation region to a total thickness when a plate material is subjected to a bending force, and can be expressed by Equation 1 below.

Here, 2a denotes the thickness of the elastic region. That is, the firing ratio PF represents the specific gravity of the plastic zone thickness at the thickness of the plate member 200.

The firing ratio PF may be set differently depending on the curvature type. Accordingly, the intermesh may also vary according to the curvature type. Normally, the target firing ratio is determined based on the defective shape present in the plate before calibrating.

For example, if there is a uniform L-curvature in the longitudinal direction of the plate (see FIG. 3A), it gives more than 50%, and if there is a longitudinal uneven L-curvature or a widthwise C- 70% or more can be given. If there is residual stress in the plane in the width direction (see FIG. 3E), it can be given 80% or more.

The firing ratio is inversely proportional to the effective radius (ρ) experienced in passing through the work roll, and specifically, the effective radius of curvature (ρ) has a relationship expressed by the following equation (2). Here, L means the interval between rolls, and IM means intermesh. 6 is a schematic diagram of the effective radius of curvature experienced by the plate material.

In this embodiment, some work rolls adjacent to the first group I of the work rolls of the third group III may be adjusted to a second gap L1 smaller than the first gap L1. The second gap L1 can be calculated by applying the intermeshed IM applied to the work roll and the effective radius of curvature equal to the effective radius of curvature of the preceding roll using Equation 2 below.

The intermesh (IM) required to obtain the target plasticity ratio is calculated by the following equation (3). Where YS is the yield strength of the plate and E is the modulus of elasticity of the plate.

Where T is the thickness of the plate, L is the spacing between the rolls, YS is the yield strength of the plate, E is the modulus of elasticity of the plate, and PF is the plasticity ratio of the plate.

In the conventional sheet material correcting apparatus, the plastic deformation of the sheet material is mainly caused by the initial part (for example, about 3) of the work rolls, and the remaining work rolls are affected by the influence Can be relatively weak. Therefore, in the case of a plate material (very high strength steel plate) having a very small thickness or a very high yield strength, the elastic restoration tendency due to the spring back is strong. Therefore, even if the working conditions are set on the same standard, Can often occur.

In order to solve the problem of shape correction of such high strength and high strength plate materials, as described in Fig. 2, the intervals L0 between the first three work rolls I on the entrance side are made the same, The interval L0 between the last three rolls II can be set to be the same as the first interval by gradually increasing the interval after setting the interval L1 to be narrow. It is possible to obtain a sufficiently small effective radius of curvature by the formula (2) even by the rolls after the first three work rolls by setting the intervals of the work rolls. As a result, it is possible to constitute the plate material to be sufficiently subjected to plastic deformation by more than three rolls on the inlet side.

Hereinafter, a sheet material manufacturing method using the sheet material correcting apparatus according to the present embodiment will be described in detail with reference to the flowchart of FIG.

The sheet material calibrating method according to this embodiment can use the sheet material calibrating apparatus shown in Figs. 1 and 2. The sheet material correcting apparatus may include a plurality of work rolls 115 arranged at upper and lower portions of a plate 111 having an inlet side and an outlet side and a plate material 200 mounted on the frame 111, have. The calibration method according to the flowchart shown in FIG. 7 may include an operation and a control process performed by the control unit 120 of the sheet material correcting apparatus.

First, the calibration method shown in Fig. 7 can be started at step S310 of calculating the intermesh according to the target firing ratio.

It is possible to set the target firing ratio PF according to the degree of shape defects and thereby calculate the intermesh of the work rolls on the input side, that is, the work rolls of the first group (I) by the equation (3) 3e).

Next, in step S320, the intermeshes of the work rolls of the first group (I) located at the entrance side are set by the calculated intermeshes, and the work of the second group (II) located on the exit side based on the thickness of the plate material You can set the intermesh of the role.

The intermeshes of the work rolls of the first group I are set by the values calculated in the step S310 and the intermeshes of the second group II are obtained by setting the output firing ratio to within 10% Can be. This calculation is performed by the control unit 120 of the sheet material correcting apparatus shown in Fig. 1, and can be implemented by driving the cylinders 121a and 121b to move the frame 111 up and down.

Next, step S330 calculates the effective radius of curvature of the work roll in the first group (on the side). The effective radius of curvature of the work roll in the first group (on the mouth side) can be calculated using the above-mentioned equation (2).

Next, in step S340, the work rolls of the third group (center) positioned between the first and second groups are grouped so that the effective radius of curvature is substantially equal to the effective radius of curvature of the first group And calculates the interval of the work rolls. The interval of the work rolls of the third group can also be calculated using the above-mentioned equation (2).

Next, these operations are performed by the control unit 120, and the positions of the work rolls of the third group are adjusted at the calculated intervals (S350).

Subsequently, the plate material is calibrated by transferring the plate material at the position of the adjusted work roll and the intermeshing condition (S360).

After the sheet material is calibrated (S360), the shape defect is measured in a state of being bitten by the right pinch roll (150b) and it is confirmed whether or not the target level is reached (S370). If the target level is not reached, the target firing ratio is increased (S380), and the above steps can be repeated until the plate shape correction is completed. When the above process is repeated, the target firing ratio may be increased by 2 to 5%.

As described above, according to the present embodiment, by adjusting the gap between the rolls so that plastic deformation is applied to the plate in performing the shape defect correction of the plate, it is possible to effectively correct even the high strength and high strength plate which is difficult to correct.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or essential characteristics thereof. .

Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but are intended to illustrate and not limit the scope of the technical spirit of the present invention. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas which are within the scope of the same should be interpreted as being included in the scope of the present invention.

100: sheet material correcting device
111: frame
112, 112a, 112b:
115, 115a, 115b: backup roll
120:
150a, 150b: pinch roll
200: plate
121a,

Claims (12)

A frame having an input side and an output side;
A plurality of working rolls mounted on the frame and arranged respectively at upper and lower portions of the plate material along the feeding direction of the plate material to contact the plate material; And
And a control unit for controlling an intermeshing of the plurality of work rolls and an interval of adjacent work rolls,
Wherein the plurality of work rolls are divided into a first group positioned on the entrance side, a second group positioned on the exit side, and a third group positioned between the first and second groups,
The control unit adjusts the first group of work rolls at a first interval and adjusts some of the work rolls adjacent to the first group of work rolls of the third group at a second interval smaller than the first interval, And the remaining work rolls of the three groups of work rolls are adjusted to be spaced apart from each other as the work rolls move away from the inlet.
The method according to claim 1,
Wherein the first group of work rolls is the first three work rolls located at the mouth,
And two adjacent work rolls located at the upper portion or the lower portion are arranged at the first interval.
3. The method according to claim 1 or 2,
The second group of work rolls being the same number as the first group of work rolls,
And the first spacing is arranged at an interval substantially equal to the first spacing.
The method according to claim 1,
Wherein the first gap has a diameter in the range of 10 to 30%.
The method according to claim 1,
Wherein an interval between the other work rolls of the third group of work rolls decreases linearly as the work rolls move away from the entrance side.
The method according to claim 1,
The second gap L is set by the following equation so as to have an effective radius of curvature equal to or smaller than the effective radius of curvature applied to the first group of work rolls,

Wherein IM is an intermeshing of the work rolls of the second group.
The method according to claim 1,
Wherein a backup roll is disposed between the plurality of work rolls and the frame, and the backup rolls have different diameters.
The method comprising: providing a sheet material calibrating apparatus including a frame having an inlet and an outlet, and a plurality of work rolls arranged respectively at upper and lower portions of a plate material mounted on the frame;
Calculating an intermesh according to a target firing ratio;
Setting intermeshes of the first group of work rolls positioned at the inlet with the computed intermesh and setting the intermeshes of the second group of work rolls located at the exit based on the thickness of the plate material;
Calculating a radius of effective curvature of the first group of work rolls;
Calculating an interval of a third group of work rolls such that a third group of work rolls positioned between the first and second groups has an effective radius of curvature substantially equal to the effective radius of curvature of the first group;
Adjusting the positions of the work rolls of the third group at the calculated intervals; And
And transferring the sheet material at the position of the adjusted work roll and the intermeshing condition.
9. The method of claim 8,
After the transferring step,
The method comprising the steps of: measuring a defective shape of a transferred sheet material to determine whether a target level has been reached; and repeating the steps of increasing the target firing ratio stepwise when the target level is not reached Way.
9. The method of claim 8,
Wherein setting the intermeshes of the second group of work rolls comprises:
And setting an intermesh of the second group of work rolls within an error of 10% of the thickness of the plate material.
9. The method of claim 8,
Wherein the first and second groups of work rolls are three work rolls located at the entrance and exit sides respectively and the interval between the first and second groups of work rolls is an interval between two adjacent work rolls located at the top or bottom &Lt; / RTI &gt;
12. The method of claim 11,
The three work rolls adjacent to the first group of the work rolls of the third group have an interval smaller than the interval of the first group and the other work rolls of the third group of work rolls move away from the mouth Wherein the first and second plates are arranged at increasing intervals.

Images