JP2003136138A - Method for correcting section steel excellent in cross section dimensional shape in total length and straightness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for correcting a section steel excellent in a cross section dimensional accuracy in the total length and straightness, and having less internal residual stress and less local material degradation. SOLUTION: The method for correcting the section steel using a correcting rolling mill 51 and a pinch roll train 52, 53 arranged in the inlet and outlet side comprises the preliminary feed of the leading end portion of the section steel that remains uncorrected in only one-way correction is to a correcting rolling mill 51, and next, bending correction in the inlet side of the pinch roll train 52, while correction-rolling in the opposite direction. By this way, the uncorrected portion in the leading end portion can be removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a method and an apparatus for straightening a shaped steel of a long material with high accuracy and high efficiency over its entire length.

[0002]

2. Description of the Related Art In the manufacturing technology of shaped steel such as rails and H-shaped steels, it is an important issue to secure dimensional accuracy and straightness of each part in the longitudinal direction, and shaped steel products having high dimensional accuracy and straightness. Since there is a limit to manufacturing only by hot rolling in order to obtain high temperature, normally, after rolling, the rolled material is further cold or warm straightened to improve the dimensional accuracy and straightness of shaped steel products. Have secured.

The conventional straightening method for rolled steel strips uses a roller leveler in which straightening rolls are arranged in a zigzag pattern vertically or horizontally along a path line (direction of transportation of the profile steel). It was general to adjust the pushing position of each straightening roll with respect to the pass line so as to gradually reduce the curvature, and to perform straightening by repeatedly bending the material to be straightened (shaped steel).

The straightening method using the roller leveler is as follows.
It requires relatively compact equipment, and once it has been set to proper conditions, it has the advantage of being easy to introduce because it allows unattended operation, but it has the following problems.

For example, in a rail product,
In recent years, it has been required to ensure high straightness over the entire length of railway vehicles due to the trend toward higher speeds, but the conventional roller leveler straightening method cannot, in principle, straighten both ends of a rail. Therefore, re-correction was required only at both ends. At present, this re-correction is performed by an intermittent press method such as three-point bending or four-point bending, which is one of the causes for remarkably reducing the productivity.

As an alternative to such a straightening method using a roller leveler, Japanese Examined Patent Publication No. 56-40644 discloses a method of straightening rolling at a rolling reduction of 10% or less using a universal rolling mill.

FIG. 9 is a diagram showing a method of straightening the left and right bends of the H-section steel by using this method. When the H-section steel A of the left bend is straightened, the reduction amount P _{1 of the} vertical roll 1 is shown. Is larger than the reduction amount P ₂ of the vertical roll 2 (P ₁ > P ₂ ), and conversely,
When straightening the right-handed H-section steel B, the reduction amount P ₂ of the vertical roll ₂ is made larger than the reduction amount P ₁ of the vertical roll 1 (P ₁ <
P ₂ ), the horizontal rolls 3 and 4 restrain the inside of the web and the flange, while the vertical rolls 1 and 2 roll down the outside of the flange to roll down the larger flange. The left and right bends are corrected by stretching the flange portion in the longitudinal direction more than the smaller one.

FIG. 10 is a diagram showing a method of correcting the vertical bending of the H-section steels. The axial center offsets of the upper and lower horizontal rolls 3 and 4 are offset according to the bending directions of the H-section steels C and D. The amount δ is adjusted, and the vertical bending is corrected by utilizing the moment in the correction direction generated by the rolling load having δ as the fulcrum length.

However, in order to obtain the required straightness, it is necessary to correct the straightness only by utilizing the difference in stretching due to such rolling.
Even if the straightness of the material to be straightened is satisfactory, for example, when straightening the left and right bends of H-section steel, the thickness of the left and right flanges must be The change is large and the product is likely to be out of size.

Japanese Patent Publication No. 56-40644 discloses arranging a universal rolling mill in a tandem to improve the straightening ability, especially in the case of straightening a shaped steel having a large bending. Straightening raises the problem of significantly increasing the equipment and maintenance costs of the straightening equipment.

[0011]

As described above, the conventional straightening by the roller leveler based on the principle of repeated bending has a problem that the unsteady portions at both ends cannot be straightened.

Further, in the rolling straightening method using a universal rolling mill as disclosed in Japanese Patent Publication No. 56-40644, since the straightness is satisfactory, the cross-sectional shape change of the shaped steel before and after straightening is large. There is a problem that the dimensional accuracy of the product is deteriorated and the dimension is likely to be out of alignment.

In view of these problems in the conventional straightening method, the present invention has the drawbacks of the conventional straightening method using only the roller leveler, that is, the generation of uncorrected areas at the unsteady portions at both ends and the shortcomings of the conventional straightening method. It is an object of the present invention to provide a method and apparatus for straightening a shaped steel, which can suppress the decrease in dimensional accuracy and which is excellent in cross-sectional dimensional accuracy and straightness in the entire length.

[0014]

The present invention is intended to solve the above problems, and the gist of the invention is to provide:
It is as follows. (1) A method of straightening a shaped steel by using a straightening rolling mill and pinch rolls arranged on the inlet side and the outlet side, the straightening being performed without rolling down the shaped steel until its tip leaves the outlet side pinch roll. After sending to the rolling mill, a step of stopping the feeding of the shaped steel, a step of gripping the shaped steel of the inlet side by the pinch roll of the inlet side and setting the shaped steel to a desired pass line, The process of setting the roll gap of the straightening mill and the straightening mill is used to straighten the shaped steel in the direction of the entry side to the tip while the pinch rolls on the entry side correct the tip of the shaped steel. The process of stopping the rolling when the roll bite of the rolling mill is reached, and then feeding the shaped steel without pressing the shaped rolling mill at least until the tip reaches the exit side pinch roll, and then feeding the shaped steel. By the process of stopping and the pinch roll on the output side The process of holding the shaped steel on the delivery side and setting the shaped steel at a desired pass line, the process of setting the roll gap of the straightening mill, and rolling the shaped steel to the rear end in the delivery direction. However, a straightening method for a shaped steel excellent in cross-sectional dimension and shape and straightness in the entire length, which is characterized by comprising a step of straightening with a pinch roll on the delivery side. (2) The setting of the roll gap of the straightening mill is substantially the same regardless of the rolling direction.
A method for straightening a shaped steel having excellent cross-sectional dimension, shape and straightness in the entire length described in.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The inventors of the present invention suppress the occurrence of uncorrected areas at both ends of the shaped steel, which are the drawbacks of the conventional straightening method using only a roller leveler, and the reduction of dimensional accuracy, which is a drawback of the conventional straightening method. In addition, as a result of diligently comparing the advantages and disadvantages of the rolling straightening by the rolling mill and the bending straightening represented by the roller leveler, the respective features are combined with the rolling straightening mechanism and the bending straightening mechanism when used individually. It has been found that the interaction between the two makes it possible to obtain an unprecedentedly high-performance light reduction straightening mechanism, and these mechanisms enable the straightening of shaped steel with excellent high-dimensional dimension accuracy and straightness over the entire length.

The straightening apparatus of the present invention comprises a straightening mill and pinch rolls installed on the inlet side and the outlet side of the straightening mill.

FIG. 1 shows an example of the straightening device of the present invention.
Universal rolling mill 51, and an inlet side pinch roll row 52 and an outlet side pinch roll row 5 on the inlet side and outlet side thereof, respectively.
3 shows a straightening device for placing 3.

The shaped steel 50 is sandwiched by horizontal rolls 54, 54 'and vertical rolls 55, 55' which are arranged above and below and on the left and right of a universal rolling mill 51 which is a straightening rolling mill, and at the same time, it is rolled at a predetermined rolling reduction. By doing so, uniform plastic deformation is given to the entire vertical cross section, and the shape of each part of the shaped steel 50 is adjusted to a predetermined dimension.

In the present invention, the cross section and the vertical cross section both refer to a cross section perpendicular to the longitudinal direction of the shaped steel.

In the straightening and rolling mill of the present invention, it is necessary to uniformly plastically deform the entire vertical cross section of the shaped steel having a complicated shape, and it is possible to bring it into contact with the entire periphery of the shaped steel to uniformly reduce the shape. In this case, any form of rolling mill, for example, a rolling mill having a hole-type roll, a universal rolling mill, or the like can be used, but it is preferable to use the universal rolling mill in terms of versatility for the material to be straightened.

On the inlet side and the outlet side of the universal rolling mill 51, a plurality of pinch rolls (5) arranged in pairs up and down and left and right along the pass line (direction of transportation of shaped steel).
6, 56 ', 57, 57', 58, 58 ', 59, 5
9 ') of the inlet side pinch roll row 52 and the outlet side pinch roll row 53 are arranged, and apply a required bending stress to the shaped steel 50.

Further, actuators (not shown) are provided on the inlet side and outlet side pinch roll rows 52 and 53 of the straightening device of the present invention, whereby the pinch rolls (56, 56 ', 57) are provided. , 57 ', 58, 58',
59, 59 ′) can be moved up and down, left and right, and in a tilt direction with respect to the horizontal direction of the rotary shaft to set a predetermined pass line position of the shaped steel 50.

When straightening the shaped steel 50 which is warped or bent during rolling, the rolls (54, 54'55, 55 ') of the universal rolling mill 51 and the pinch roll rows 52 on the input and output sides, 53 pinch rolls (56, 5
6 ', 57, 57', 58, 58 ', 59, 59') is loaded with a pressing force due to a geometrical positional deviation from a predetermined pass line due to the warp or bending of the shaped steel 50, Due to these reaction forces, a bending moment is generated in the shaped steel 50 near the entrance side and the exit side of the universal rolling mill 51, and a mechanism for correcting the shaped steel 50 into a predetermined pass line works.

As described above, in the rolling straightening apparatus of the present invention, each pinch roll of the pinch roll row is movable in the vertical and horizontal directions and in the tilt direction with respect to the horizontal direction of the rotation axis. Thereby, the vertical and horizontal positions of each pinch roll are changed, or preferably, the inclination of the rotation axis of the pinch roll is further changed to the vertical and horizontal positions of the pass line,
And, preferably, the twist of the pass line is further adjusted. As described above, it is possible to provide an actuator on each of the pinch rolls of the pinch roll row and adjust the position for each pinch roll. Adjust the vertical and horizontal positions for each.

FIGS. 2 (a) and 2 (b) are shaped steels to be straightened in the straightening method of the present invention (FIG. 2 (b)) and the conventional straightening method using only a roller leveler (FIG. 2 (a)). Fifty
It is the figure which showed the correction model for comparing the deformation characteristics of.

In the conventional straightening method using only the roller leveler shown in FIG. 2 (a), the position of the point B where the straightening roll 73 of the straightening roll 73 contacts the straightening steel 50 is set to the position of the straightening roll 72 of the straightening roll 72. The relative movement amount with respect to the position of the contact portion B ′, that is, the pushing amount is increased by Δ (see FIG. 2).
It is set to a position where it is pushed (above (a)) and the straightening roll 7
1 is an example in which a straightening force is applied to bend the shaped steel 50 in an upward direction (a convex shape downward in FIG. 2A) with the point A of contact with the shaped steel 50 of 1 as a fulcrum. Contact point B of shaped steel
A downward reaction force (downward in FIG. 2A) with respect to the correction force is generated at the point.

On the other hand, in the straightening method of the present invention shown in FIG. 2B, the roll-out pinch rolls 59 of the rolls 55, 55 'of the universal rolling mill, the roll 59' of the 59 'and the shaped steel 5 are used.
The position of the contact point B with 0 is set to the position of the contact point B ′ between the roll 57 ′ of the entry side pinch rolls 57 and 57 ′ of the rolls 55 and 55 ′ of the universal rolling mill and the shaped steel 50.
When the push-in amount Δ is set to the same amount as in FIG. 2A (upward in FIG. 2B), the shaped steel 5 being straightened
Similarly, a downward reaction force (downward in FIG. 2B) against the straightening force is generated at the contact point B of 0, but the rolling steel 55, 5 of the universal rolling machine, and 5
By the rolling by 5 ', the reduction amount u is applied in the plastic working region, and the reduction amount u reduces the reaction force at the point B of the contact portion of the shaped steel 50 during straightening. Also, preferably, tensile tension (in the direction of the left and right arrows in FIG. 2B) between the rolls 55 and 55 ′ of the universal rolling mill and the input side pinch rolls 57 and 57 ′ and the output side pinch rolls 59 and 59 ′. The rolls 55 and 5 of the universal rolling mill are
Since the rolling amount 5'is applied with the reduction amount u in the plastic working region, the deformation characteristics of the shaped steel 50 during straightening change, and the reaction force at point B also changes accordingly.

That is, FIG. 3 shows the method of the present invention shown in FIG.
In (b)) and the straightening model of the conventional method (FIG. 2 (a)), the straightening reaction force at the contact point B of the shaped steel 50 being straightened was calculated by elasto-plastic finite element analysis, and the comparison result was shown. It is a thing. Here, in order to know the relationship between the rolling reduction of the rolls 55, 55 ′ of the universal rolling mill and the straightening reaction force at the contact point B between the shaped steel 50 and the pinch roll 59 ′ during straightening in the straightening model of the method of the present invention. In addition, the horizontal axis of FIG. 3 is the shaped steel 50 of FIG.
And A'of the rolling mill rolls 55, 55 '
The rolling reduction rate (%) at the point was defined.

As is apparent from FIG. 3, the straightening by the rolls 55, 55 'and the inlet and outlet pinch rolls 57, 57', 59, 59 'of the universal rolling mill of the present invention is as follows.
The straightening reaction force at the contact point B between the shaped steel 50 and the roll being straightened can be reduced as compared with the conventional straightening using only the roller levelers 71, 72, 73, and the straightening reaction force is universal rolling. It can be lowered by increasing the reduction rate (%) during rolling by the rolls 55, 55 'of the mill.
Further, it is understood that the straightening reaction force can be further reduced by applying tensile tension to the shaped steel by the roll of the universal rolling mill and the pinch rolls on the input side and the output side.

In the present invention, this is in the roll bite which is already in the yield state due to the rolling of the rolls 55, 55 'of the universal rolling mill, that is, the contact portion A between the section steel of FIG. 2 (b) and the rolling mill roll. Bending stress due to the pushing amount Δ of the point B at the contact point of the exit side pinch rolls 59, 59 ′ with the shaped steel and the rolls 55, 55 of the universal rolling mill with respect to the vertical cross section near the points A and A ′. And the tension tensions between the inlet and outlet pinch rolls 57, 57 'and 59, 59' (corresponding to the inlet and outlet pinch roll rows 52, 53 in FIG. 1) act in superposition. Since the shaped steel 50 easily yields due to an increase in the rolling reduction and the tensile tension of the rolls 55, 55 'of the universal rolling mill, the straightening reaction force at the point B of the contact between the shaped steel 50 and the pinch roll 59' is reduced. It is considered to be a thing.

FIG. 4 shows the shape steel 50 being straightened and the roll or pinch roll of the roller leveler in the straightening model of the present invention method (FIG. 2B) and the conventional method (FIG. 2A) of FIG. It is a figure which shows the relationship between the correction reaction force of the contact point B, and the amount of springback after correction (a phenomenon in which a shaped steel deforms due to release of internal stress when it is removed from the correction machine). The amount of springback after correction is the correction reaction force (correction reaction force P (a) by the roller leveler, correction reaction force P (b) by the method of the present invention)
It can be seen that the larger is, the larger is.

3 and 4, the straightening method of the present invention is superior to the conventional straightening method in the amount of springback after straightening, that is, the shape fixability after straightening, and the dimensional accuracy and straightness are high. It turns out that correction is possible.

In the above, comparative examination between the conventional method and the method of the present invention was carried out on the straightening characteristics of the steady straightening portion of the shaped steel, that is, the portion excluding both ends of the shaped steel. Next, the straightening characteristics of the front and rear edges will be examined.

In the roller leveler of FIG. 2 (a), at least the roll 73 and the shaped steel cannot directly contact each other when the front end of the shaped steel is located between the rolls 71 and 73. Therefore, after the tip of the shaped steel passes the roll 71,
The bending moment does not act until it comes into contact with the roll 73. That is, it can be seen that bending correction is impossible in the portion of the distance between the rolls 71 and 73 from the tip of the shaped steel. Similarly, it is impossible to correct the roll interval at the rear end.

In the case of the method of the present invention shown in FIG. 2 (b), even if the rear end of the shaped steel is located between the rolls 55 and 57, the rolls 55 and 55 'of the straightening mill sandwich the shaped steel. Since rolling is performed, when a pushing force is applied by the pinch rolls 59 and 59 'on the exit side, a straightening bending moment acts on the section of the shaped steel sandwiched between the rolls 55 and 55'. Output side pinch roll 5
If 9 and 59 'are set at the target pass line positions, the shaped steel along the pass line can be straightened as in the stationary part. That is, bending straightening is possible up to the rear end of the shaped steel. On the other hand, even when the front end of the shaped steel is located between the rolls 55 and 59, the rolls 55 and 55 'of the straightening mill sandwich and roll the shaped steel, so that it is pushed in by the pinch rolls 57 and 57' on the entry side. When a force is applied, a corrective bending moment acts on the section of the shaped steel sandwiched between the rolls 55 and 55 '. However, in this case, there is no means for controlling the shaped steel at the target pass line position on the exit side. Therefore, it is conceivable to set the entrance-side pinch rolls 57 and 57 'to the target pass line positions. However, when a disturbance occurs during rolling, the influence affects the shaped steel on the exit side, and therefore it is more unstable than the case of the rear end portion. For straightening the shaped steel tip, roll 5 from the shaped steel tip.
It can be seen that the bending correction is unstable in the portion of the distance of 5.

Therefore, the present invention was realized as follows, focusing on the fact that the tip portion of the shaped steel may be straightened in the same manner as the rear end portion of the shaped steel capable of stabilizing straightening. That is, straightening is unstable, and the shaped steel until the tip of the shaped steel leaves the pinch roll on the exit side is sent to the exit side without being rolled by a straightening mill in advance, and straightening rolling is performed in this direction in the incoming side. If so, the front end of the shaped steel is threaded like the rear end of the shaped steel. In this state, if a pinch roll is installed in the material passing direction of the straightening mill, straightening can be performed stably like the rear end portion. That is, if the shaped steel is gripped by the pinch roll on the entry side, positioned at a desired pass line, and straightened and rolled, straightening can be performed up to the end. After that, the threading direction of the shaped steel is changed and the tip of the already straightened shaped steel is sent without rolling until at least the tip reaches the exit side pinch roll, and the shaped steel is gripped by the exit side pinch roll. The position is set to a desired pass line, and the remaining uncorrected portion is straightened and rolled in the exit direction to the rear end. At this time, since the rear end of the shaped steel can be straightened stably as described above, it can be seen that the entire length including the leading and trailing ends of the shaped steel can be straightened as a target.

When straightening and rolling the vicinity of the tip of the shaped steel in the opposite direction, it is necessary to pass the shaped steel without rolling, so that an operation of opening the roll gap of the rolling mill occurs. Therefore, it is necessary to set the gap between the rolling rolls before performing the straightening rolling. In this case, it is necessary to adjust the roll gap twice when rolling one section steel, and the roll gap may be different between the two. When the gap is different between the two, a step is generated in the longitudinal direction of the shaped steel after straightening, which is not preferable. Therefore, the setting of the roll gap twice is made substantially the same to prevent the generation of the step in the longitudinal direction of the shaped steel. If the roll chock is tightened by screwing, the screw-in amount of the first screw is stored, and the screw-in amount stored in the second setting is adjusted. In the case of the hydraulic pressure reduction method, the position of the chock when first tightened is stored, and tightening is performed so that the position of the chock that was stored when setting the second time is stored. By these methods, it is possible to manufacture shaped steel without steps by controlling the roll gap during rolling to a target value.

Further, as described above, the straightening mill may be one that plastically deforms the entire vertical cross section of the shaped steel, but it is preferable to use a universal rolling mill in which uniform deformation conditions can be easily set. Further, it is necessary to have a system capable of reverse rolling in which the rolling direction can be reversed and to have a tightening device for tightening the roll chock with a rolling load. In addition, pinch rolls capable of gripping the shaped steel and moving in the vertical and horizontal directions must be installed on the inlet side and the outlet side of the straightening mill. Since pinch rolls are installed on both sides of the straightening rolling mill, even if the rolling direction changes, it is possible to hold the shaped steel after straightening rolling with either pinch roll and control the shape of the shaped steel on the target pass line. It will be possible.

FIG. 5 shows a shaped steel straightening system according to the present invention. As an example of the embodiment of the present invention, a universal rolling mill 51 and pinch roll rows 52 and 53 on the inlet side and the outlet side thereof are shown. Fig. 2 shows a conceptual diagram of the configured straightening device (same as in Fig. 1) and its control system.

An actuator (not shown) for changing the position of each roll and its control boards 60, 61, 62 are provided in the universal rolling mill 51 and the input and output side pinch roll rows 52, 53, respectively. Sensors 63, 64 and 65 for measuring a roll position, a roll reaction force and the like are provided, and these are connected to a calculation control device 66 having a recording device 67 by a signal line. The actuators provided in the inlet-side and outlet-side pinch roll rows 52 and 53 can change the pass line position of the shaped steel by moving each pinch roll in the vertical and horizontal directions.

When the shaped steel 50 is straightened, the position of each roll of the universal rolling mill 51 and each roll reaction force are measured by the sensor 63, and these measurement signals are fetched into the control device 66 for calculation. Universal rolling mill 5
The proper roll position (opening) for obtaining the target rolling reduction in No. 1 is determined, and the control signal is transmitted to the control board 60 of the universal rolling mill 51, and the roll position (opening) is transmitted via the actuator. Is adjusted to control the rolling reduction ratio to a target value. As a result, the vertical cross-sectional shape of the shaped steel 50 is maintained at a target value, and the shaped steel 50 in the roll bite is maintained in a plastically deformed state.
The correction load of 2,53 is reduced.

On the other hand, the inlet and outlet pinch roll rows 5
In Nos. 2 and 53, the respective roll positions and the respective roll reaction forces are detected by the sensors 64 and 65, and the measurement signals thereof are taken into the arithmetic and control unit 66 for arithmetic operation to estimate the shape of the shaped steel 50 and While determining the optimum roll position, opening degree, etc. of the inlet and outlet pinch roll rows 52, 53 for correcting the defective shape of the steel, the control signal is input to the inlet and outlet pinch roll rows 52, It is transmitted to the control panels 61 and 62 of 53, and the position and opening of each pinch roll are adjusted via the actuator to control the shape of the shaped steel after correction to a target value.

Incoming and outgoing pinch roll rows 5
The roll positions and the roll reaction force sensors 64 and 65 attached to the rolls 2 and 53 measure the roll position and the components of the roll reaction force in the vertical and horizontal directions. The vertical and horizontal loads applied to the shaped steel 50 during straightening and the vertical and horizontal positions of the pinch rolls are detected from the measured values, and the pinch rolls 52 and 53 are gripped by the inlet and outlet pinch roll rows 52 and 53. A control device for calculating the load (lateral load and bending moment) acting on the shaped steel, the elastic deformation amount of the shaped steel due to this load, and then the bending amount of the shaped steel from each roll position and the elastic deformation amount of the shaped steel. In addition to the estimation using the calculation function of 66, the gripping posture of the shaped steel 50 that cancels the bending amount of the shaped steel is calculated, and the control signal of the optimum position of each pinch roll corresponding thereto is input and output sides. It is transmitted to the control boards 61, 62 of the pinch roll rows 52, 53, and the relative position of each pinch roll is adjusted by a mechanism that can be individually adjusted via an actuator to adjust the relative position of the shaped steel. Controlled so as to be in value.

In the shaped steel after rolling, in addition to bending over the entire length, local bending such as edges may occur.
In such a case, it is preferable that a load meter, preferably a load meter and a displacement meter, be provided on the universal rolling mill 51 and each roll of the input side and output side pinch roll rows,
By controlling the roll position (opening degree) of the universal rolling mill 51 and each roll position of the input side and output side pinch roll rows 52 and 53 based on the measurement signals from the load meter and the displacement meter, the short length and the long length are controlled. Regardless of the scale, it is possible to control the total length of the shaped steel 50 and the correction of the vertical, horizontal, and leftward bending that occurs locally.

When straightening an ordinary shaped steel, the universal rolling mill 51 and the pinch roll rows 5 on the input side and the output side are used.
By aligning the 2, 53 pass lines and straightening the shaped steel under the condition that it is fixed,
By correcting the vertical bending, it is possible to obtain a shaped steel having excellent dimensional accuracy and straightness in which the dimensions of each portion of the shaped steel are within the target tolerance over the entire length.

On the other hand, in the case of straightening of a shaped steel which requires very strict dimensional accuracy and internal material (small residual stress and work hardening), it is bent left and right as shown in FIGS.
It is necessary to control the position of each pinch roll of the input side and output side pinch roll rows 52 and 53 depending on the shape defect of the vertically bent shape steel.

That is, when straightening a shaped steel having left-right bending as shown in FIG. 6, each pinch roll position of either the input side or the output side pinch roll row 52, 53 is set to the universal rolling. With respect to the path line position of the machine 51, it is set to the right position in the case of a section steel with a left bend (a) and to the left side in the case of a section steel with a right bend (b), respectively.

As shown in FIG. 7, in the case of straightening a shaped steel having vertical bending, the pinch roll position of either the input side or the output side pinch roll row 52, 53 is set to the universal rolling mill 51. In the case of the shape steel (a) with the upper bend, the position is set to the upper position in the case of the shape steel with the lower bend (b) with respect to the pass line position of 1.

6 to 7, for the sake of convenience, the straightening control logic in the case of straightening a shaped steel in which left and right bending and up and down bending are independently generated is described. Needless to say, when the shaped steel produced by the above is straightened, these pinch roll position setting methods are arbitrarily combined as appropriate.
Further, the setting of the pass line position when performing correction may be manual setting, or may be automatically set and controlled by applying the above-mentioned control system. The setting can be selected from the method of fixing the pass line constant as described above or the method of applying the correction control logic.

[0051]

EXAMPLES The effects will be described below with reference to examples of the present invention.

In the rolling process of the general shaped steel shown in FIG. 8, the dimensional accuracy and straightness of the shaped steel after straightening were compared using the straightening device of the present invention and the conventional roller leveler straightening machine, respectively.

The straightening device of the present invention is a universal rolling mill 5 which is an example of the embodiment of the present invention shown in FIG.
A straightening device and control system composed of 1 and its input and output pinch roll rows 52, 53 were used.

The straightening machine of FIG. 5 of the present invention is replaced with a roller leveler straightening machine provided in the rolling process of the general shaped steel shown in FIG. 8, and the position of the pinch roll row is manually set to form the shaped steel. They were corrected and their abilities were compared.

First, in the roller leveler, it was possible to find and correct the condition capable of correcting the bending of the steady portion of the shaped steel by the basic setting method in which the pushing amount of the roll was increased on the inlet side and decreased on the outlet side. However, with respect to the ends of the shaped steel, it was observed quite often that an uncorrected region having the same length as the interval between the straightening rolls was generated and the tolerance was exceeded.
These out-of-tolerance shaped steels had to be dealt with by straightening them with a press having extremely low productivity, or by cutting off the ends on the premise of yield loss.

On the other hand, according to the method of the present invention, when the pinch roll row is set so as to coincide with the pass line, the target tolerance including the both ends of the shaped steel can be almost achieved. In addition, no significant change was observed in the vertical cross-sectional shape when cut at any place including the end of the shaped steel.

From the above results, it was found that the method of the present invention can completely replace the conventional roller leveler.

The above is the case of cold straightening incorporated as a part of the rolling process of the shaped steel of FIG. 8, but the technique of the present invention can be applied to a wide range of processes such as hot straightening and warm straightening. Is.

[0059]

According to the present invention, the rolling straightening method having an excellent uniform deformability and the bending straightening method having a nonuniform deformation but having a good shape controllability are appropriately combined to make up for the drawbacks of the both and to fully exhibit their advantages. By devising so that
It has become possible to straighten both ends of shaped steel, which is extremely difficult to achieve with conventional straightening methods.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of an apparatus in a correction method of the present invention.

FIG. 2 is a diagram showing a model for comparing the straightening characteristics of the conventional technique and the technique of the present invention, FIG. 2 (a) shows a roller leveler, and FIG. 2 (b) shows a model of the present invention in each technique. .

3 is a diagram showing the relationship between the straightening reaction force and the rolling reduction obtained by the model of FIG.

FIG. 4 is a diagram showing a relationship between a springback and a correction reaction force obtained by the model of FIG.

FIG. 5 is a diagram showing an embodiment of a shaped steel straightening system of the present invention.

FIG. 6 is a diagram showing the principle of straightening left and right bends of a shaped steel according to the technique of the present invention, and FIG. 6 (a) is a left bent shaped steel;
(B) shows the case of right-handed shaped steel, respectively.

FIG. 7 is a diagram showing the principle of straightening and bending a shaped steel according to the technique of the present invention. FIG.
(B) shows the case of shaped steel with downward bending.

FIG. 8 is a diagram showing a process of rolling and straightening a shaped steel.

FIG. 9 is a diagram showing a conventional correction technique.

FIG. 10 is a diagram showing a conventional correction technique.

[Explanation of symbols]

1, 2 ... Vertical roll 3, 4 ... Horizontal roll 10 ... H-section steel 11 ... Web of H-section steel 12 ... H-section steel flange 50 ... Shaped steel 51 ... Universal rolling mill 52 ... Entry side pinch roll row 53 ... Delivery side pinch roll row 54, 54 '... Horizontal roll of universal rolling mill 55, 55 '... Vertical roll of universal rolling mill 56, 56 '... Horizontal pinch rolls on the input side pinch roll row 57, 57 '... Vertical pinch rolls on the input side pinch roll row 58, 58 '... Horizontal pinch rolls in the output pinch roll row 59, 59 '... Vertical pinch rolls on the output side pinch roll row 60 ... Control panel and actuator for universal rolling mill 61 ... Entry side pinch roll control panel and actuator 62 ... Ejection side pinch roll control panel and actuator 63 ... Universal rolling mill sensor 64 ... Input side pinch roll row sensor 65 ... Sensor on the output side pinch roll row 66 ... Arithmetic control device 67 ... Recording device 71, 72, 73 ... Rolls of roller levelers Δ: Bending correction amount u ... rolling reduction A, B, C, D ... H section steel

Claims (2)

[Claims] 1. A method for straightening a shaped steel using a straightening mill and pinch rolls arranged on the inlet side and the outlet side thereof, wherein the shaped steel is not pressed down until its tip leaves the outlet side pinch roll. After feeding to the straightening mill, the step of stopping the feeding of the shaped steel, and the step of gripping the shaped steel on the inlet side by the pinch roll on the inlet side and setting the shaped steel to a desired pass line. And the step of setting the roll gap of the straightening mill, and straightening the shaped steel in the direction of the entry side by the straightening rolling mill to the tip while straightening it with the pinch rolls on the entry side so that the tip of the shaped steel is The process of stopping the rolling when the roll bite of the straightening mill is reached, and then feeding the shaped steel without being reduced by the straightening mill until at least the tip reaches the exit side pinch roll, Process of stopping feeding and pinch roll on the output side By the process of gripping the shaped steel on the exit side to set the shaped steel at a desired pass line, the step of setting the roll gap of the straightening mill, and the shaped steel to the rear end in the outgoing side direction. A method for straightening a shaped steel excellent in cross-sectional dimension and shape and straightness in the entire length, which comprises a step of straightening with a pinch roll on the delivery side while rolling. 2. The shape excellent in cross-sectional dimension and shape and straightness in the entire length according to claim 1, wherein the setting of the roll gap of the straightening mill is substantially the same regardless of the rolling direction. Steel straightening method.