JP7648881B2 - Steel sheet pile manufacturing equipment - Google Patents

Description

The present invention relates to a manufacturing device for steel sheet piles, such as hat-shaped steel sheet piles and U-shaped steel sheet piles.

Hat-shaped steel sheet piles, U-shaped steel sheet piles, and other steel sheet piles with joints at both ends are manufactured by a groove rolling method as shown in Patent Document 1, for example. Specifically, a typical process of the groove rolling method is known to be to first heat a rectangular material to a predetermined temperature in a heating furnace, and then roll it in sequence using a roughing mill, an intermediate rolling mill, and a finishing rolling mill equipped with grooves.

In particular, when manufacturing large, asymmetric products such as hat-shaped steel sheet piles, many grooves are required to manufacture them using the roughing mill, intermediate mill, and finishing mill, and large-scale equipment is required. In addition, the shaping method becomes complicated, and the product is more likely to have shape variations and defective shapes. Furthermore, many rolls are required to manufacture steel sheet piles of different shapes. In response to this, as shown in Patent Document 2, a technology is known in which a steel sheet pile is rolled and manufactured by hot rolling, and then bent (hereinafter also referred to as bending) by cold processing using roll forming, to manufacture steel sheet piles with a width that exceeds that of rolling equipment and steel sheet piles with a high cross-sectional height.

Non-Patent Document 1 discloses a technology for manufacturing lightweight steel sheet piles by using multiple cold forming machines to bend and form thin steel plate with a thickness of about 4 to 7 mm. This technology has the advantage that the plate is easier to form because it is thinner than hot-rolled steel sheet piles, and there is almost no difference in the shape of the cropped parts on the left and right sides because the steel plate is bent almost symmetrically using multiple rolls, making it less likely to cause misalignment (misalignment of the bite).

It is also known that when manufacturing asymmetric steel sheet piles, the material being rolled can warp up and down, bend left and right, or twist at the exit side of the rolling mill, especially during intermediate rolling and finish rolling. In response to this, for example, Patent Document 3 discloses a technology in which plate-shaped guides (first to third guides) are provided at the entry and exit sides of the rolling mill to prevent warping up and down, bending left and right, and twisting.

Japanese Unexamined Patent Publication No. 10-192905 JP 2003-230916 A JP 2009-119513 A

"Roll Forming", edited by the Japan Society for Technology of Plasticity, Corona Publishing, pp. 83-85, 111-113

However, in the conventional groove rolling method exemplified in Patent Document 1, one pass of rolling is performed with one groove while shifting the groove from the intermediate rolling process to the finish rolling process, so the total elongation of the rolled material is restricted according to the number of grooves used for rolling, resulting in a small elongation length of the product. Furthermore, when manufacturing large steel sheet pile products using the conventional groove rolling method, the number of grooves that can be arranged on one roll is reduced, the roll diameter becomes large, reducing manufacturing efficiency, and a large rolling mill is required.

In addition, in the manufacturing method of steel sheet piles as exemplified in Patent Document 2, bending is performed by cold working, and furthermore, the corners of the rolled material are not directly pressed down using flat support rolls, which causes problems such as the difficulty of applying plastic deformation directly to the corners and the inability to perform effective bending, and the fact that cold working tends to result in large springback after forming. In addition, when the web and flange are formed at different times using multiple forming rolls (support rolls), there is also the problem that the efficiency of bending is reduced because the fulcrum is shifted in the longitudinal direction of the rolled material.

In addition, in the manufacturing method of steel sheet piles described in Patent Document 2, the temperature when bending by cold working is set to a temperature below the A1 transformation temperature or below the recrystallization temperature. Bending in such a temperature range imposes a large processing load, and problems such as deterioration of the material, such as a decrease in elongation and toughness, and an increase in residual stress, may occur. Therefore, in order to solve these problems, it becomes necessary to arrange a large number of forming rolls, which leads to problems of large equipment and complex structure.

The technology described in Non-Patent Document 1 is a cold bending technology, and cold bending is performed in a multi-stage stand while the steel plate is restrained and fed by pinch rolls without cropping. In contrast, when bending is performed continuously with hot rolling, asymmetric crops and bends are likely to be formed in the rolled material, which can easily cause misalignment and jamming. Therefore, there is a problem that it is difficult to apply the technology described in Non-Patent Document 1 to bending large steel sheet piles continuously with hot rolling.

In addition, in the technology described in the above Patent Document 3, the rolling mill that hot rolls the steel sheet pile is provided with first to third guides across the width of the steel sheet pile, aiming for stable rolling. However, there is no mention of a configuration for providing suitable guides for forming that involves a large change in cross-sectional shape, such as bending. In other words, when bending a steel sheet pile after rolling, it is necessary to apply a guide configuration or the like that can deal with the twisting that occurs when the rolled material is bitten into the equipment and can deal with the large cross-sectional deformation that occurs at the entry side of the roll bite in the steady state specific to bending, and it cannot be said that it is appropriate to apply the technology described in Patent Document 3 to bending steel sheet piles.

In view of the above circumstances, the object of the present invention is to provide a steel sheet pile manufacturing device that can suppress the longitudinal dimensional fluctuation of the rolled material without impairing centering properties, even when asymmetric crops or bends are formed in the rolled material during the rolling process due to asymmetry in the product shape, temperature deviation, or axial misalignment of the upper and lower rolls during rolling, causing misalignment and twisting of the tip of the rolled material in the bending machine, when manufacturing steel sheet pile products by bending the rolled material after hot finishing rolling.

In order to achieve the above object, according to the present invention, there is provided a manufacturing device for manufacturing steel sheet piles by hot rolling, which includes a roughing mill, an intermediate mill, a finishing mill, and a bending machine that bends the rolled material continuously with the finishing rolling, the bending machine being composed of one or more stands including a first stand, and a web restraining guide that restrains the upper surface of the web corresponding part of the rolled material is provided at least upstream of the first stand of the bending machine, and the outer width of the web restraining guide is configured to be narrower than the inner distance between the left and right flanges of the pre-deformed part of the rolled material in a steady state at the installation position of the web restraining guide.

The roll gap directly below the upper and lower hole type rolls of the bending machine in the portions facing the web corresponding portion and the flange corresponding portion of the rolled material may be configured to be larger than the thickness of the web corresponding portion and the flange corresponding portion, respectively.

A roller guide may be provided as the web restraint guide, and a conveying roller may be provided at a position facing the roller guide with respect to the rolling line.

A pair of opposing upper and lower roller guides may be provided on the rolling line as the web restraint guide.

The transport roller may be located at the same position as the roller guide or shifted downstream in a plan view.

Of the pair of upper and lower roller guides, the lower roller guide may be located at the same position as the upper roller guide or at a position shifted downstream in a plan view.

The web restraining guide is an inner guide that extends in the rolling direction along the inner surface of the rolled material, and the cross-sectional shape of the inner guide may be configured to change continuously from a cross-sectional shape that approximates the rolled material after finish rolling to the cross-sectional shape of the rolled material immediately before bending.

At least one of a lower guide or a conveying roller having a generally flat plate shape extending in the rolling direction along the lower surface of the rolled material may be provided.

The web restraining guide may be provided at a position upstream from the roll axis position of the grooved roll of the first stand by a distance L that satisfies the following formula (1).
L>L1+L2...(1)
Here, L1 is the distance between the bending start position and the roll axis position of the grooved roll of the first stand, and L2 is the crop length of the flange corresponding portion of the rolled material.

Outer guides may be provided on the outside of both widthwise ends of the rolled material, extending in the rolling direction.

According to the present invention, when manufacturing steel sheet pile products by bending the rolled material after hot finishing rolling, even if asymmetric crops or bends are formed in the rolled material and the tip of the rolled material becomes misaligned or twisted in the bending machine, centering is not impaired, dimensional fluctuations in the longitudinal direction of the rolled material are suppressed, and large bending can be performed with a small number of stands.

FIG. 2 is a schematic explanatory diagram of a rolling line. FIG. 2 is a schematic cross-sectional side view of a bending machine. FIG. 2 is a schematic front view of the bending machine. FIG. 4 is a schematic enlarged front view showing a hole shape of a first stand. FIG. 11 is a schematic enlarged front view showing the hole shape of the second stand. 5 is an explanatory diagram of the shape change of a rolled material being bent in a first stand and a second stand. FIG. 1 is a schematic plan view showing a state immediately before the workpiece to be rolled is bitten into the bending machine. FIG. FIG. 2 is a schematic front view showing how the workpiece is bitten in the bending machine. FIG. 13 is a schematic plan view of a configuration in which a roller guide is provided. FIG. 11 is a schematic front view showing how the rolled material is bitten in a configuration provided with roller guides. FIG. 4 is a schematic side view of a support mechanism for the roller guide. FIG. 4 is a schematic front view of a support mechanism for the roller guide. FIG. 11 is a schematic explanatory diagram of a first modified example of the present invention. FIG. 13 is a schematic explanatory diagram of a second modified example of the present invention. 14(a) is a schematic cross-sectional view showing the state of the inner guide, lower guide, outer guide, and rolled material at the A-A' cross section and the B-B' cross section of FIG. 14(a). 13A and 13B are schematic explanatory diagrams illustrating modified examples of the outer guide. 1 is a graph showing the results of Comparative Example 1. 1 is a graph showing the results of Example 1. 1 is a schematic explanatory diagram showing the cross-sectional shape of the rolled material A when it is bitten, and the cross-sectional shape of the pre-deformed portion of the rolled material in a steady state, in a cross section perpendicular to the rolling direction including the roll axis of the roller guide. 1 is a graph showing a numerical analysis of the state of pre-deformation of rolled material A during bending. FIG. 4 is a schematic explanatory diagram of an outer width Q of a roller guide serving as a web restraining guide. FIG. 13 is a schematic explanatory diagram showing a modified example of the roller guide. 13 is a graph for a third embodiment of the present invention.

The following describes an embodiment of the present invention with reference to the drawings. In this specification and the drawings, components having substantially the same functional configuration are given the same reference numerals to avoid repeated explanation. In this embodiment, a case where a hat-shaped steel sheet pile is manufactured as a steel sheet pile product is described. In the following, for the sake of explanation, the steel material in the rolling line T may be collectively referred to as "rolled material A", and its shape may be illustrated appropriately in each drawing using dashed lines, solid lines, etc.

(Outline of the rolling line)
Fig. 1 is a schematic explanatory diagram of a rolling line T (indicated by a dashed line in the drawing) as a manufacturing device for manufacturing a hat-shaped steel sheet pile according to an embodiment of the present invention, and rolling machines and the like provided in the rolling line T. In Fig. 1, the rolling direction of the rolling line T is indicated by an arrow, and the material to be rolled flows in the direction, and is rolled and bent in each rolling machine and bending machine on the line to form a product.

As shown in FIG. 1, the rolling line T is arranged, in order from upstream, with a roughing mill 10, a first intermediate rolling mill 13, a second intermediate rolling mill 16, a finishing rolling mill 19, and a bending mill 20. In addition, an edger rolling mill 14 is arranged adjacent to the first intermediate rolling mill 13, and an edger rolling mill 17 is arranged adjacent to the second intermediate rolling mill 16.

In the rolling line T, rectangular material (rolled material A) heated in a heating furnace (not shown) is hot rolled in the rough rolling mill 10 to the finishing rolling mill 19, and is hot shaped by the bending machine 20 arranged in a straight line with the finishing rolling mill 19 to become the final product, a hat-shaped steel sheet pile. For the sake of explanation, the rolled material A rolled by the rough rolling mill 10 is also called the rough shaped material, the rolled material rolled by the first intermediate rolling mill 13 and the second intermediate rolling mill 16 is also called the intermediate material, and the rolled material rolled by the finishing rolling mill 19 is also called the finished material 19a. In other words, the finished material 19a is shaped (cross-section changed) by the bending machine 20 to become the final product (i.e., the hat-shaped steel sheet pile product).

The roughing mill 10, first intermediate mill 13, second intermediate mill 16, and finishing mill 19 arranged in the rolling line T, as well as the associated edge mills 14 and 17, are common equipment that has been used in the manufacture of steel sheet piles for some time, and therefore detailed descriptions of their device configurations, etc. will be omitted in this specification.

(Schematic configuration of bending machine)
Next, the detailed configuration of the bending machine 20 will be described with reference to the drawings. Fig. 2 is a schematic side cross-sectional view of the bending machine 20, and Fig. 3 is a schematic front view of the bending machine 20. The bending machine 20 shown in Figs. 2 and 3 bends the finishing material 19a that has been finish-rolled in the finishing rolling mill 19. Fig. 3 also shows a schematic front view of a first stand 22 provided in the bending machine 20, which will be described below. Here, in this embodiment, the bending machine 20 is described as being composed of two forming stands (forming stands 22 and 23, which will be described below), but the bending machine 20 may be composed of one or any number of stands.

As shown in FIG. 2, the bending machine 20 according to this embodiment has two forming stands 22, 23 (hereinafter also referred to as the first stand 22 on the upstream side and the second stand 23 on the downstream side) arranged adjacent to each other in tandem. Also, as shown in FIG. 3, each stand 22, 23 is engraved with a forming groove (groove 45, 55 described later) consisting of an upper groove roll and a lower groove roll, and the groove shape is different between the first stand 22 and the second stand 23.

Here, the roll configuration and the groove shape of the first stand 22 and the second stand 23 will be described. FIG. 4 is a schematic enlarged front view showing the groove shape of the first stand 22, and FIG. 5 is a schematic enlarged front view showing the groove shape of the second stand 23. FIG. 4 shows the cross-sectional shape of the finished material 19a in a state before forming by the bending machine 20 with a dashed line, and FIG. 5 shows the cross-sectional shape of the finished material 19a' in a state before forming by the second stand 23 with a dashed line. In the following, an example will be described in which a rolled material having a substantially hat-shaped shape is bent and formed in an upward open position (with the web corresponding part described later positioned downward and the arm corresponding part positioned upward).

3 and 4, the first stand 22 is provided with an upper perforated roll 40 and a lower perforated roll 41 supported by a housing 44, and the upper perforated roll 40 and the lower perforated roll 41 form a perforated roll 45. The shape of the perforated roll 45 from the part corresponding to the flange to the part corresponding to the joint is one step before the hat-shaped steel sheet pile product (i.e., approximately the hat-shaped steel sheet pile product shape). The perforated roll 45 changes the angle between the part corresponding to the flange of the finishing material 19a (i.e., the flange corresponding part) and the part corresponding to the web of the finishing material 19a (i.e., the web corresponding part), and the angle between the part corresponding to the arm of the finishing material 19a (i.e., the arm corresponding part), and bends and forms the height and width of the finishing material 19a into a predetermined shape (i.e., a cross-sectional shape similar to the product). In particular, when manufacturing large hat-shaped steel sheet piles, it is preferable to use a method in which the rough rolling mill 10 to the finishing rolling mill 19 roll the rolled material (rough material to finishing material 19a) in a shape with a low height, and then the bending machine 20 bends the rolled material to increase its height to the desired product height.

As shown in FIG. 5, the second stand 23 has an upper hole type roll 50 and a lower hole type roll 51 supported by a housing 54, and the upper hole type roll 50 and the lower hole type roll 51 form a hole type 55. This hole type 55 has a shape close to the desired product shape, and changes the angle between the part corresponding to the flange (i.e., the flange corresponding part) formed in the first stand 22 of the bending machine 20 and the part corresponding to the web of the finishing material 19a (i.e., the web corresponding part), and the angle between the part corresponding to the arm (i.e., the arm corresponding part), respectively, to form the flange shape, arm shape, and joint shape into a predetermined shape (i.e., the product shape). That is, in this second stand 23, the inclination angle of the flange corresponding part, which was insufficient for the product shape in the forming in the first stand 22, is changed to an angle corresponding to the product shape.

Here, the roll gaps in the above-mentioned grooved dies 45 and grooved dies 55 during bending (the roll gap between the upper grooved roll 40 and the lower grooved roll 41 and the roll gap between the upper grooved roll 50 and the lower grooved roll 51) are configured to be larger than the thickness of the flange-corresponding portion and the web-corresponding portion of the finishing material 19a. That is, in the bending machine 20, the plate thickness of the finishing material 19a is not reduced, and the grooved rolls of the first stand 22 and the second stand 23 and the finishing material 19a are configured to come into contact with each other at some predetermined points described later to perform bending. Specifically, the roll gaps in the portions facing the web-corresponding portion and the flange-corresponding portion are preferably 0.5 mm to 3 mm larger than the thickness of the flange-corresponding portion and the web-corresponding portion of the finishing material 19a. In addition, the roll gaps in the above-mentioned grooved dies 45 and grooved dies 55 at the portions corresponding to the arm-corresponding portion of the finishing material 19a may also be configured to be larger than the thickness of the arm-corresponding portion over the entire cross section.

(Forming of rolled material in bending)
Next, the forming of the rolled material in the above-mentioned stands 22 and 23 will be described. Fig. 6 is an explanatory diagram of the shape change of the rolled material (finished material 19a) bent in the first stand 22 and the second stand 23, (a) shows a schematic cross-sectional view before processing in the first stand 22, (b) shows processing in the first stand 22, and (c) shows processing in the second stand 23. As shown in Fig. 6(a), the finished material 19a is substantially hat-shaped and is composed of a web corresponding part 60 that is substantially horizontal, flange corresponding parts 62, 63 connected to both ends of the web corresponding part 60 at a corner part 70 at a predetermined angle, arm corresponding parts 65, 66 connected to the end of each flange corresponding part 62, 63 different from the connection side with the web corresponding part at a corner part 71 at a predetermined angle, and joint corresponding parts 68, 69 formed at the tip of the arm corresponding parts 65, 66. In addition, the finishing material 19a has a thickness that is approximately the same as the product thickness due to rolling in the finishing rolling machine 19, and the shape of the joint corresponding parts 68, 69 is also approximately the shape of the product joint.

The finishing material 19a shown in FIG. 6(a) is bent in the groove 45 of the first stand 22 so that the inclination angle θ1 of the flange corresponding portions 62, 63 (angle θ1 of the flange corresponding portions relative to the horizontal rolling pitch line) becomes large (becomes the angle θ2 shown in FIG. 6(b)). By bending in this manner, the finishing material 19a reaches the desired height as shown in FIG. 6(b). That is, in the first stand 22, bending is performed so that the height of the finishing material 19a becomes large. The angle change θ2-θ1 due to bending here is defined as the first bending angle Δθ1.

Next, as shown in FIG. 6(c), in the hole 55 of the second stand 23, bending is performed to change the inclination angle θ2 of the flange corresponding parts 62, 63 to the product angle θ3. That is, as shown in FIG. 6(b) and (c), the inclination angle θ2 of the flange corresponding parts 62, 63 is formed to be the product angle θ3. In bending in each stand, it is preferable to press at least the inner side 72 of the corner part 70, which is the connection part between the web corresponding part 60 and the flange corresponding parts 62, 63, and the inner side 73 of the corner part 71, which is the connection part between the flange corresponding parts 62, 63 and the arm corresponding parts 65, 66, to sufficiently plastically deform the corner part. Note that since the inclination angle of the flange corresponding parts 62, 63 may change even after passing through the second stand 23, it is preferable to determine the shape of the hole 55 taking into account the angle change. The angle change θ3-θ2 due to bending here is the second bending angle Δθ2.

In the bending process shown in Fig. 6(a) to (c), bending may be performed in each stand to appropriately change the angle between the flange corresponding parts 62, 63 and the arm corresponding parts 65, 66. The final shape is to be such that the arm corresponding parts 65, 66 are approximately horizontal and conform to the product shape.

(Problems with crop formation in rolled material before bending)
In the rolling line T configured as described above, the rolled material A (finished material 19a) after finish rolling is bent by the bending machine 20 to manufacture the final product. In this way, the rolled material A is pushed from the finishing rolling machine 19 and bitten into the bending machine 20, and bending is performed continuously with the finish rolling, making it easy to bit into the material, and the final product can be manufactured with high productivity. On the other hand, when a steel sheet pile product is manufactured using a slab as a material, the flange thickness of the product is usually larger than the web thickness, so that after finish rolling, the flange corresponding part at the longitudinal end of the rolled material A precedes the web corresponding part. As a result, it is known that a shape defect part (so-called crop) is generated at the tip of the rolled material A. That is, the present inventors have found that a crop is formed at the tip of the rolled material A just before the biting of the bending machine 20, and various problems occur when the biting of the bending machine 20 is started in this state.

Figure 7 is a schematic plan view showing the state immediately before the rolled material is bitten into the bending machine 20, and shows a part of the longitudinal tip of the rolled material A. As shown in Figure 7, outer guides 80 are provided on both sides of the width direction of the rolled material A upstream of the first stand 22 of the bending machine 20, and the rolled material A is bitten into the first stand 22 while being guided by these outer guides 80. As shown in the figure, a crop is generated at the tip of the rolled material A after finish rolling. When the crop is generated, due to the axial misalignment of the upper and lower rolls during rough rolling to finish rolling and temperature deviation, etc., a crop of asymmetric length may be generated due to the difference in the amount of reduction of the left and right flange corresponding parts 62, 63.

When the material A to be rolled is bitten into the bending machine 20 with a crop of asymmetric length generated, one of the leading flange corresponding parts (flange corresponding part 62 in the figure) comes into contact with the lower hole type roll 41 of the bending machine 20 first, as shown in Figure 7. That is, one of the flange corresponding parts comes into contact with the lower hole type roll 41 first, and the flange corresponding part is lifted by contact with the lower hole type roll 41, so that the entire cross section of the material A to be rolled is bitten into the bending machine 20 while tilting obliquely.

Figure 8 is a schematic front view showing the biting of the rolled material in the bending machine 20, and is a schematic view of the biting state seen from the stand entry side. For simplification, in Figure 8, only the rolls and the rolled material are shown, and the housing and the like are omitted. As shown in Figures 7 and 8, one flange corresponding part (here, flange corresponding part 62) contacts the lower hole type roll 41 before the other flange corresponding part (here, flange corresponding part 63) and is lifted up, so that the entire cross section of the rolled material A is tilted diagonally (counterclockwise in the figure), and the biting progresses in this state. If the biting progresses in this state, the twist generated in the rolled material A becomes large, and there is a risk that the biting of the subsequent rolled material A becomes unstable.

In addition, when the material A is bitten into the bending machine 20 in a state where a crop with an asymmetric length is generated, if the material A is bent in the longitudinal direction, the widthwise center of the material A may be misaligned with the widthwise center of the rolls (upper perforated roll 40 and lower perforated roll 41) of the bending machine 20. As shown in FIG. 7, an outer guide 80 is provided upstream of the bending machine 20, but the spacing between the outer guides 80 is set with a certain margin relative to the width of the material A (for example, a margin of several tens of mm), so the outer guide 80 alone may not be sufficient. If the material A is bitten into the bending machine 20 in a state where the widthwise center positions of the rolls are misaligned, the twist of the material A increases, resulting in poor centering, known as center misalignment.

As explained above, when the rolled material A after finish rolling is fed into the bending machine 20, there is a concern that the material may not be able to pass through the bending machine 20 due to instability in the feeding, the occurrence of twisting, poor centering, etc. The inventors have recognized these various problems and have thoroughly studied solutions to them. Below, the means for solving these problems will be explained.

(Roller guide configuration)
The present inventors investigated the deformation state of the cross-sectional shape of the rolled material A in the bending machine 20, and conducted intensive studies on means for effectively suppressing instability of biting, occurrence of twisting, poor centering, etc. For example, as in Patent Document 3, in a rolling mill for rolling steel sheet piles (e.g., hat-shaped steel sheet piles), a technique is known in which the upper and lower surfaces of the web, flange, and arm are restrained by guides installed on the entry side and exit side of the rolling mill, respectively, in order to suppress twisting of the rolled material. However, in the bending machine 20 according to the present embodiment, in a steady state, the overall width and height of the rolled material A change in the longitudinal direction due to pre-deformation at the roll bite entry side, and even at the same position on the roll bite entry side, the cross-sectional shape of the rolled material A changes significantly between the time of biting and the steady state, so that it is difficult and undesirable to restrain the flange and arm from above and below.

From this perspective, the inventors have devised a configuration in which a web restraining guide is provided to restrain the web (web corresponding portion 60) of the rolled material A upstream of the bending machine 20 (first stand 22). Below, the configuration in which a roller guide 90 is provided as a web restraining guide will be described with reference to the drawings.

Figure 9 is a schematic plan view of a configuration with a roller guide 90, showing the state immediately before the rolled material is bitten into the bending machine 20, and shows a portion of the longitudinal tip of the rolled material A. Also, Figure 10 is a schematic front view showing the state of the rolled material being bitten in a configuration with a roller guide 90, and is a schematic view of the biting state as seen from the entry side of the bending machine 20. Note that in Figures 9 and 10, components having the same functional configuration as those in Figures 7 and 8 above may be given the same reference numerals and their description may be omitted. Also, the roller guide 90 is supported at a predetermined position using a roller support mechanism, a vertical lifting mechanism, etc., but these support mechanisms, lifting mechanisms, etc. are not shown in Figures 9 and 10.

As shown in Figures 9 and 10, a roller guide 90 is provided upstream of the first stand 22 of the bending machine 20, located above the web corresponding portion 60 of the rolled material A, as a web restraining guide that restrains the web corresponding portion 60 between the rolled material A and the conveying table (or conveying roller) below the rolled material A. In the configuration of this embodiment, a plurality of conveying rollers 95 are provided for conveying the rolled material A, and the web corresponding portion 60 is restrained between one of the conveying rollers 95 and the roller guide 90.

The dimensions of the roller guide 90 can be designed arbitrarily, but preferably, the dimensions should be determined based on the relationship with the cross-sectional shape of the rolled material A at the installation position of the roller guide 90. An example of how to determine the outer width Q of the roller guide 90 will be described below. FIG. 19 is a schematic explanatory diagram showing the cross-sectional shape of the rolled material A when it is bitten (solid line in the figure) and the cross-sectional shape of the pre-deformed part of the rolled material A in a steady state (broken line in the figure) in a cross section perpendicular to the rolling direction including the roll axis of the roller guide 90. FIG. 20 is a graph obtained by numerically analyzing the state of pre-deformation of the rolled material A in bending forming, where (a) shows the longitudinal change in the steady part of the left and right flange inner interval W, and (b) shows the longitudinal change in the steady part of the flange corresponding inclination angle (flange angle) θ. Note that FIG. 20(a) shows data at positions where the height h from the top surface of the web corresponding part 60 is 200 mm, 250 mm, and 300 mm. Additionally, the horizontal axis in FIG. 20 is the distance from the first stand 22 in the rolling direction, with 0 indicating directly below the first stand 22.

As shown in FIG. 20(a), at positions h=200 mm, 250 mm, and 300 mm, the left and right flange inner distance W changes due to pre-deformation compared to the left and right flange inner distance W0 before forming. For example, looking at the position h=250 mm, 2.5 m upstream of the first stand 22 (-2500 mm position in the graph), it can be seen that the left and right flange inner distance W has decreased by about 170 mm from before forming due to pre-deformation. From this result, it can be said that it is desirable to design the outer width Q of the roller guide 90 as a web restraining guide to be smaller than the left and right flange inner distance W when pre-deformation occurs in the steady portion. This suppresses twisting when biting and prevents the occurrence of defects in the pre-deformed portion in the steady state.

As shown in FIG. 20(b), the flange angle θ in the longitudinal direction also changes significantly due to pre-deformation in the steady-state portion of the rolled material A. From this result, the outer width Q of the roller guide 90 as a web restraining guide can be evaluated based on the value of the flange angle θ, and it can also be designed to be located inside the flange.

It is preferable that the outer width Q of the roller guide 90 as a web restraining guide designed as described above is the outer width of the entire structure including the roller guide 90 main body and the roller support part 105 described below. Here, the width Q of the entire structure of the roller guide 90 and the roller support part 105 may differ depending on the height position. Figure 21 is a schematic explanatory diagram of the outer width Q of the roller guide 90 as a web restraining guide. As shown in Figure 21, the width Q of the entire structure of the roller guide 90 and the roller support part 105 differs depending on the height position, and may be only the roll main body width Q1 or the width Q3 of the entire roll and support part. Therefore, as described above with reference to FIG. 20(a), when designing the outer width Q of the roller guide 90 based on the relationship between the height h from the top surface of the web corresponding portion 60 when pre-deformation occurs in the steady portion and the distance W between the inner sides of the left and right flanges, or as described above with reference to FIG. 20(b), when designing the outer width Q of the roller guide 90 based on the value of the flange angle θ, the outer width Q used in the design can be the outer width Q (Q1 to Q3) at a suitable position, such as Q1 to Q3 depending on the position.

As shown in FIG. 9, when the roll axis position of the grooved roll of the first stand 22 is P1 and the roll axis position of the roller guide 90 is P2 in a plan view, the roller guide 90 is provided so that the roll axis position P2 is located at a position separated by a predetermined distance L upstream from the roll axis position P1. At least one of the transport rollers 95 must be provided at a position substantially below the roller guide 90 (a position facing the roller guide 90 in the rolling line T), and for example, at least one of the transport rollers 95 may be provided at the same position as the roll axis position P2 of the roller guide 90 in a plan view as shown in FIG. 9.

Here, the installation position of the roller guide 90 on the upstream side of the first stand 22 of the bending machine 20 must be such that the web corresponding portion 60 can be restrained at the stage when the leading flange corresponding portion 62 contacts the lower hole type roll 41 of the first stand 22. Specifically, the roller guide 90 must be provided so that the distance L between the roll axis positions P1 and P2 is greater than the sum (L1 + L2) of the distance L1 between the position where the tip of the leading flange corresponding portion 62 starts to contact the lower hole type roll 41 (i.e., bending start position) and the roll axis position P1 of the lower hole type roll 41 (or the upper hole type roll 40) and the crop length L2 of the flange corresponding portion 62 occurring with respect to the web corresponding portion 60. That is, the position where the roller guide 90 is provided must be provided upstream from the roll axis position P1 of the grooved roll of the first stand 22 by a distance L that satisfies the following formula (1).
L>L1+L2...(1)

The crop length L2 of the flange corresponding portion 62 relative to the web corresponding portion 60 is a value that changes depending on the stretch difference between the web corresponding portion 60 and the flange corresponding portion 62 and operational fluctuations, and is a value that differs for each individual rolled material. Therefore, the maximum value of the crop length L2 can be arbitrarily determined depending on the product size and operational conditions.

In addition, the distance L1 between the position where the tip of the preceding flange corresponding portion 62 starts to contact the lower groove roll 41 and the roll axis position P1 of the lower groove roll 41 can be determined by a geometric relationship. Specifically, the distance L1 can be determined using the following formula (2) from the flange line length B of the rolled material A, the inclination angle θ1 of the flange corresponding portion before bending, the inclination angle θ2 of the flange corresponding portion after bending in the stand (here, the first stand 22), the arm radius Ra and web radius Rw of the lower groove roll 41, and the center deviation amount X, as shown in Figures 9 and 10. The center deviation amount X is the deviation amount between the width direction center position of the rolled material A and the width direction center position of the groove roll of the first stand 22 (a state in which the width direction center position of the rolled material A is shifted toward the preceding flange side with respect to the width direction center of the groove roll is a positive value).

As an example, under manufacturing conditions where the flange line length B is 542 mm, θ1 is 30°, θ2 is 50°, Ra is 912 mm, Rw is 497 mm, and X is 30 mm, L1 is 607 mm. For example, if the crop length L2 is 900 mm, the roller guide may be installed at a position where the distance L from the roll axis position P1 is more than 1507 mm. It is preferable to set the distance L with a margin, taking into account fluctuations in the distances L1 and L2 during operation.

(Configuration of roller guide support mechanism and lift mechanism)
When providing the roller guide 90 according to the present embodiment described above, the support mechanism, lifting mechanism, etc. may be provided as desired, and various configurations are possible, such as providing a housing separate from the bending machine 20 and using that housing to support the roller guide 90, or attaching a support mechanism and lifting mechanism to the housing 44 of the first stand 22 of the bending machine 20 to support the roller guide 90. Here, as an example, a configuration in which a support mechanism and lifting mechanism are attached to the housing 44 of the first stand 22 to support the roller guide 90 is illustrated and described.

Figure 11 is a schematic side view of the support mechanism of the roller guide 90, and Figure 12 is a schematic front view of the support mechanism of the roller guide 90. For simplification, Figures 11 and 12 focus on the first stand 22 of the bending machine 20, and Figure 12 is a schematic front view seen from the entry side (upstream side) of the first stand 22. Also, the rolled material A is not shown in Figure 11, and the roller guide 90 is marked with diagonal lines in Figures 11 and 12.

As shown in FIG. 11, the first stand 22 is provided with a guide support part 100 that is fixed to the housing 44 of the stand and extends toward the upstream side of the stand, and a lifting mechanism 103 that is attached to the guide support part 100. A roller guide 90 is attached to the lower end of the lifting mechanism 103 via a roller support part 105 so as to be freely rotatable. The lifting mechanism 103 is, for example, a hydraulic cylinder, and can raise and lower the roller guide 90 and roller support part 105 together to any height by driving the lifting mechanism 103.

The roll width of the roller guide 90 can be designed as desired, and it is preferable that the roll width is, for example, 2/3 or more of the width of the web-compatible portion 60, so as to allow for the material A to be rolled to shift in the width direction and to be stably restrained. The roll diameter of the roller guide 90 can be designed as desired depending on the scale of the equipment, such as the guide support portion 100 and the roller support portion 105, and may be designed to be, for example, 500 mm or more.

In this way, the roller guide 90 provided with the lifting mechanism 103 and the transport roller 95 can effectively restrain the web-corresponding portion 60 of the rolled material A upstream of the first stand 22. In particular, an effective restraining effect can be achieved by appropriately raising and lowering the roller guide 90 according to the deformation state and thickness of the rolled material A.

(Action and Effect)
As described above, with the bending machine 20 (particularly the first stand 22) configured with the roller guide 90 according to the present embodiment described with reference to the drawings, when the longitudinal end of the rolled material A is bitten into the bending machine 20, even if the flange corresponding portion 62, which is ahead of the web corresponding portion 60, is bitten first, the web corresponding portion 60 is restrained, thereby suppressing misalignment and twisting during biting. This suppresses material passing defects during bending, and improves the centering ability of the rolled material A.

In particular, when providing the roller guide 90, by setting it in a suitable installation position determined by the above formulas (1) and (2), the web corresponding portion 60 can be restrained at the stage where the preceding flange corresponding portion 62 contacts the lower hole type roll 41 of the first stand 22, and an effective restraining effect can be obtained. As a result, even when performing large bending in the first stand 22, asymmetric crop portions are formed in the rolled material, and even if the preceding flange corresponding portion 62 is bitten first, the rolled material remains centered while being bent, thereby avoiding uneven biting and poor material passing.

As mentioned above, the roll gap immediately below the roll of the groove 45 during bending is configured to be larger (for example, about 0.5 mm to 3 mm) than the thickness of the flange corresponding portion and the web corresponding portion of the finishing material 19a. In addition, it is preferable to configure the roll gap immediately below the roll of the groove 45 during bending to be larger than the thickness of the arm corresponding portion and corner portion (the connection portion between the web corresponding portion and the flange corresponding portion, and the connection portion between the flange corresponding portion and the arm corresponding portion) of the finishing material 19a. This has the great effect of correcting the misalignment and facilitating centering by allowing the rolled material A to be bitten into the groove 45 while the web restraint guide suppresses twisting when the flange corresponding portions 62, 63 are misaligned and bitten.

Although one embodiment of the present invention has been described above, the present invention is not limited to the illustrated embodiment. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

For example, in the above embodiment, the bending machine 20 is illustrated and described as being composed of a first stand 22 and a second stand 23, but the scope of application of the present invention is not limited to this. For example, the bending machine 20 may be a single stand, or may be composed of any number of multiple stands. When the bending machine 20 is composed of multiple stands, bending can be shared among the stands. The number of stands is appropriately determined based on the balance between the bending angle and the capital investment.

In the above embodiment, the roller guide 90 as a web restraining guide is illustrated as being configured to restrain the web corresponding portion 60 between the conveying table (or conveying roller) below the rolled material A (see Figures 9 to 11), but the configuration of the roller guide 90 is not limited to this. For example, as shown in Figure 22, the roller guide 90 may be a pair of upper and lower roller guides (upper roller guide 90a and lower roller guide 90b). In such a configuration, the upper roller guide 90a and the lower roller guide 90b may be positioned at the same position in the rolling direction in a plan view, or the lower roller guide 90b may be positioned shifted downstream.

In addition, in the above embodiment, the upper and lower hole type rolls of the bending machine 20 can be configured so that only one of the upper and lower rolls is driven and the other is not driven. By configuring so that only one of the upper and lower hole type rolls is driven, it becomes easier to balance the speed of the material passing through when bending is performed in tandem with multiple stands, and the generation of tension in the material being rolled due to an imbalance in the speed balance between multiple stands is suppressed, stabilizing the material passing through and suppressing unnecessary changes in the shape of the material being rolled. In addition, the driving mechanisms such as the motor, spindle, and gears for driving the rolls can be simplified, which allows for the miniaturization of equipment and reduction in equipment costs.

In addition, in the above embodiment, a roller guide 90 is provided upstream of the first stand 22 of the bending machine 20, but a similar roller guide 90 may be provided in each of the multiple stands that make up the bending machine 20. In this case, bending can be performed efficiently because bending is performed in all of the multiple stands without compromising the centering of the rolled material, and problems such as poor material passage can be avoided.

(First Modification of the Invention)
In the above embodiment, when the rolled material A is restrained on the upstream side of the first stand 22, the web corresponding portion 60 is restrained by the roller guide 90 and the transport roller 95 located substantially below it, but the positional relationship between the roller guide 90 and the transport roller 95 is not limited to this. Here, as a first modified example of the present invention, a configuration in which the position of the transport roller 95 facing the roller guide 90 is shifted will be described.

Figure 13 is a schematic diagram of the first modified example of the present invention. In FIG. 13, components having the same functional configuration as those in FIG. 9 described in the above embodiment may be given the same reference numerals and their description may be omitted. As shown in FIG. 13, in the first modified example of the present invention, the roll axis position of the transport roller 95 located approximately below the roller guide 90 is shifted toward the first stand 22 side (i.e., downstream side) in a plan view. In this way, by adopting a configuration in which the transport roller 95 is arranged downstream of the roller guide 90 in a plan view and the roller guide 90 and the transport roller 95 restrain the web corresponding portion 60 of the rolled material A, it is possible to more effectively suppress the twisting of the tip portion (so-called crop) of the rolled material A, and to stably perform bending forming.

(Second Modification of the Invention)
In the above embodiment, a configuration in which a roller guide 90 is provided as a web restraining guide that restrains the rolled material A on the upstream side of the first stand 22 has been illustrated and described, but the configuration of the web restraining guide is not limited to this. That is, an inner guide and a lower guide extending in the rolling direction (direction in which the rolled material passes) in a region including the upstream side of the first stand 22 may be provided as the web restraining guide. Here, as a second modified example of the present invention, a configuration in which an inner guide 110 and a lower guide 112 are provided in the first stand 22 as web restraining guides will be described.

Figure 14 is a schematic diagram of a second modified example of the present invention, where (a) is a schematic diagram of the inner guide 110 and the lower guide 112 provided on the first stand 22 as viewed from the side, and (b) is a schematic diagram of the inner guide 110, the lower guide 112, and the outer guide 80 as viewed from the front. Note that in Figure 14(a), some of the transport rollers 95 are illustrated, and in Figure 14(b), for simplification, components other than the inner guide 110, the lower guide 112, and the outer guide 80 are omitted. Also, in Figure 14, components having the same functional configuration as those in Figures 1 to 12 described in the above embodiment may be assigned the same reference numerals and their description may be omitted.

As shown in FIG. 14(a), the inner guide 110 and the lower guide 112 extend in the rolling direction from the upstream to the downstream of the first stand 22, and in the vicinity of the first stand 22, the inner guides 110a, 110b and the lower guides 112a, 112b are arranged on the upstream and downstream sides of the first stand 22. That is, the rolled material A during bending is bitten into the first stand 22 while being guided (restrained) from both the top and bottom by the inner guide 110a, the conveying roller, and the lower guide 112a on the upstream side of the stand. Note that FIG. 14 illustrates the vicinity of the first stand 22, and describes the inner guides 110a, 110b, and the lower guides 112a, 112b, but an inner guide and a lower guide may also be provided downstream of the second stand 23.

As shown in FIG. 14(b), the inner guide 110a protrudes downward from above the rolling line T, and its shape is similar to the shape of the material A to be rolled. In other words, the lower surface of the inner guide 110a is shaped to fit the upper surface of the web of the material A to be rolled, which is roughly hat-shaped. Similarly, the shape of the inner guide 110b installed downstream of the stand may also be designed to match the shape of the material A to be bent in the second stand 23.

On the other hand, as shown in FIG. 14, the lower guide 112a is generally flat and is arranged to follow the underside of the web of the material A to be rolled when it is bitten. In this way, the material A to be rolled is bitten into the first stand 22 with its upper and lower surfaces guided by the inner guide 110a, the transport roller, and the lower guide 112a.

Here, as described above, the shape of the inner guide 110a is close to the shape of the material A to be rolled, but the shape of the central portion from the web corresponding portion to the flange corresponding portion is configured to change in accordance with the change in shape of the material to be rolled in the rolling direction in a steady rolling state, and changes continuously along the rolling direction (longitudinal direction of the material A to be rolled). Figures 15(a) and (b) are schematic cross-sectional views showing the state of the inner guide 110a, lower guide 112a, outer guide 80, and material A to be rolled at the A-A' and B-B' cross sections of Figure 14(a). As shown in Figures 15(a) and (b), the A-A' cross section on the upstream side of the inner guide 110a has a shape that corresponds to the cross-sectional shape of the rolled material A immediately after finish rolling, which is the process before bending (finished material 19a in the figure), and the B-B' cross section just before bending in the first stand 22 begins has a shape that corresponds to the cross-sectional shape of the rolled material A (finished material 19c in the figure) that has undergone pre-deformation and has a larger flange angle than the upstream side, so that the cross-sectional shape of the guide changes continuously in the longitudinal direction.

In this way, the angle between the web corresponding portion and the flange corresponding portion of the rolled material A (finished material 19a) gradually changes due to pre-deformation until the position where bending in the first stand 22 starts. Therefore, by changing the side angle of the inner guide 110a in the longitudinal direction between the A-A' cross section on the upstream side and the B-B' cross section in accordance with the change in angle between the web corresponding portion and the flange corresponding portion of the rolled material A, the centering property of the rolled material A can be improved without generating guide defects. Regarding the change in the longitudinal cross-sectional shape due to this pre-deformation, for example, the change in the cross-sectional shape from the start position of pre-deformation to the start position of bending may be predicted by simulation, and the guide shape may be determined. Alternatively, the guide shape may be set so as to linearly connect the shape of the rolled material A and the shape of the caliber 45 of the first stand 22. Also, as shown in Figures 15(a) and 15(b), approximately horizontal portions may be provided on both sides of the inner guide 110a to guide the arm portion or joint portion of the rolled material.
Even in this case, since the inner guide 110a can restrain the upper surface of the web even if twisting occurs due to misalignment, when the inner guide 110a is provided, it is preferable to configure, as an example of the installation position, that the position L that satisfies the above formula (1) is located between the A-A' cross section and the B-B' cross section upstream of the roll axis position P1 of the grooved roll of the first stand 22. Moreover, the longitudinal length of the lower guide 112a is arbitrary, and may be extended to the A-A' cross section position in FIG.

As shown in Figure 14, even if the rolled material A (finished material 19a) is bent or warped, in order to stably guide it within the guide, it is desirable to change the shape of the inner guide 110a so that the tip of the inner guide 110a has a shape that widens upward and narrows further upstream of the A-A' cross section, and so that the shape of the inner guide 110a roughly follows the cross-sectional shape of the upstream side as it approaches the A-A' cross section.

In addition, the length of the inner guide 110a of the first stand 22 in the rolling direction (longitudinal direction) is preferably, for example, from just below the roll to the A-A' cross section, up to a position 2m or more upstream. This is because, in the case of bending in this embodiment, pre-deformation of the rolled material occurs from 2m or more upstream just below the roll in a steady state, so by setting the tip position of the guide 2m or more upstream just below the roll and setting the shape of the tip side of the guide (the side farther from the bending machine 20, for example the A-A' cross section) to approximately match the cross-sectional shape of the rolled material A (finished material 19a), it is possible to perform bending without causing guide defects even in a steady state while ensuring the inductivity of the tip of the rolled material A. Here, it is necessary to provide a small clearance between the rolled material A and the inner guide 110a.

It is also desirable for the A-A' cross section position of the inner guide 110a to be located at least 2 m upstream from just below the roll, but this distance can be somewhat shorter, for example 1.8 m or more, and is within the acceptable range. In this case, the guide shape at the A-A' cross section can be adjusted to match the shape of the rolled material that has undergone some pre-deformation. Also, if the distance from just below the roll to the A-A' cross section position is large and it is difficult to continuously position the inner guide 110a from the position where pre-deformation occurs to just before bending begins in the first stand 22, it is still effective to position the inner guide 110a within an appropriate range in the longitudinal direction.

In addition, in this modified example, the distance between the lower surface of the inner guide 110a and the lower guide 112a is preferably 1.5 times or more and 3 times or less than the thickness of the web corresponding part of the material A to be rolled, from the viewpoint of suppressing guide defects and stably guiding the material to be rolled. In addition, the gap between the lower surface of the inner guide 110a and the upper surface of the web corresponding part of the material A to be rolled in the material passing state is preferably 3 mm or more and less than the thickness of the web corresponding part of the material A to be rolled, from the viewpoint of suppressing guide defects and stably guiding the material to be rolled.

As shown in FIG. 14(b), the outer guide 80 is composed of a right guide 80a and a left guide 80b, which are installed on both sides of the width of the material A (finished material 19a) to be rolled when the material is passed through, and each guide is a substantially flat plate extending in the rolling direction. The right guide 80a and the left guide 80b are provided at a predetermined distance from each other, and the distance does not change in the rolling direction. That is, the predetermined distance is a length that matches the overall width of the material A (finished material 19a) before bending in the first stand 22. In addition, when the guide is provided in the second stand 23, the length is a length that matches the overall width of the material A to be rolled after passing through the first stand 22. Here, the overall width refers to the width of the material A to be rolled in the left-right direction, and the length that matches the overall width refers to a length obtained by adding a clearance of, for example, about 10 mm to the representative value of the overall width of the material A to be rolled, taking into account the variation in the overall width.

The configuration of the second modified example of the present invention has been described above with reference to Figs. 14 and 15. However, the shapes and arrangements of the guides described here are merely examples, and the present invention is not limited thereto. For example, the roller guide 90 according to the above embodiment may be combined with the inner guide 110 of this modified example, and a configuration in which the roller guide 90 is incorporated into the inner guide 110, or an inner guide 110 is added between the roller guide 90 and the first stand 22, may also be considered. In addition, as shown in Fig. 16, the upstream tip of the outer guide 80 may be shaped to open outward, so that the rolled material A can be stably guided within the guide even if it is curved. In addition, a configuration in which a guide mechanism for roughly adjusting the center position of the rolled material A in the left-right direction is installed separately from the outer guide 80 on the further upstream side of the outer guide 80 may also be considered.

In the above description of the embodiment and its modified examples, the case of manufacturing hat-shaped steel sheet piles as the final product has been taken as an example, but the present invention is not limited to this and can also be applied to the manufacture of steel sheet pile products such as U-shaped steel sheet piles.

(First embodiment)
As a first example of the present invention, an aluminum model experiment was conducted to evaluate material passing properties for bending in one stand (for example, see the first stand 22 described in the above embodiment). The operating conditions in the experiment were, in actual machine equivalent values, a constant flange line length of the rolled material of 542 mm, Ra of 912 mm, crop length L2 of 530 mm, differences in left and right flange crop lengths of 0, 150, and 300 mm, and center offsets of ±15 and ±30 mm. The flange angle of the rolled material before bending (θ1) and the bending angle (Δθ1=θ2-θ1) were as shown in Table 1 below.

Under the above operating conditions, a model experiment was conducted on a rolled material having a roughly hat-shaped shape in a stand without roller guides as Comparative Example 1, and the material passing properties were evaluated. Figure 17 is a graph showing the results of Comparative Example 1, where ◯ indicates stable material passing and × indicates unstable material passing.

In addition, under the above operating conditions, in Example 1, a roller guide was installed 2.5 m upstream of the stand, and the guide was designed so that the rolled material would not come into contact with the roller guide under any of the conditions in Table 1, even with the maximum flange angle of 51° of the pre-deformed part in the steady state at the roller guide installation position. A model experiment of bending a rolled material having an approximately hat-shaped shape was carried out with the gap between the web top surface of the rolled material and the roller guide set to 10 mm, and material passing properties were evaluated. Figure 18 is a graph showing the results of Example 1, where ◯ indicates stable material passing and × indicates unstable material passing.

Model experiments were conducted under the five conditions shown in Table 1 above for both Comparative Example 1 and Example 1. As shown in Figure 17, in Comparative Example 1, the biting became unstable under three of the five conditions, resulting in failure to pass the material through. On the other hand, as shown in Figure 18, in Example 1, the material could be passed stably under all five conditions. In other words, it was found that by installing the roller guide, the conditions (bending angle) under which bending can be performed in a state where the material can be passed stably are increased, and bending can be performed effectively.

Second Example
As a second embodiment of the present invention, a hat-shaped steel sheet pile having a total width of 1400 mm, a height of 501 mm, a flange angle of 63°, a web thickness of 17.0 mm, and a flange thickness of 13.2 mm was manufactured by bending after finish rolling. As the second embodiment and the second comparative example, bending was performed under two conditions: the flange angle after finish rolling was 30°, and the first stand was changed to 50°, and the second stand was changed to 63°.

In Example 2, a roller guide was provided, the flange line length of the rolled material was constant at 542 mm, Ra was 912 mm, and the spacing of the outer guides was 30 mm wider than the overall width of the rolled material. Distance L1 was 598 mm, the maximum crop length L2 was 900 mm, and the distance L from the roller guide was set to 2.5 m. The roll width of the roller guide was set to 90% of the width of the web-corresponding part of the rolled material, and the guide was designed so that the rolled material would not come into contact even with a flange angle of 37° of the pre-deformation part in the steady state at the roller guide installation position, and the gap between the web top surface of the rolled material and the roller guide was set to 10 mm. On the other hand, in Comparative Example 2, except for the configuration without a roller guide, manufacturing was performed under the same conditions as Example 2.

In Comparative Example 2, which does not have a roller guide, twisting occurred immediately after the tip of the rolled material was bitten by the first stand of the bending machine, and many materials could not be passed through due to the large misalignment. On the other hand, in Example 2, which has a roller guide, stable bending was performed, and good hat-shaped steel sheet piles were produced.

(Third Example)
As a third embodiment of the present invention, for a hat-shaped steel sheet pile having an overall width of 900 mm, height of 368 mm, flange angle of 69°, web thickness of 15.0 mm, and flange thickness of 11.3 mm, when bending was performed by installing a web restraint guide as shown in Figure 14 upstream of the first stand, the guide shape was determined by simulation analysis, and the shape of the web restraint guide was determined based on the results of the analysis, and bending was performed.

Figure 23 shows the results of a simulation of the longitudinal change in the flange-corresponding inclination angle (flange angle) θ of the rolled material in bending in the steady state, with the flange angle immediately below the roll of the first stand set to 0. As shown in Figure 23, the flange angle after finish rolling is 40°, and the flange angle starts to change from a position about 3 m upstream from immediately below the roll of the first stand. Here, the change in the flange angle is small up to about 2 m upstream from immediately below the roll. Therefore, the A-A' cross-sectional position of the inner guide 110a of the web restraining guide was set 2 m upstream from immediately below the roll of the first stand, and the B-B' cross-sectional position was set 0.68 m upstream from immediately below the roll of the first stand. In addition, the side angle of the inner guide at the A-A' cross-sectional position and the B-B' cross-sectional position was set to match the flange angle of the rolled material at each position in Figure 23, the gap between the inner guide and the inner flange inner surface was set to 5 mm, and the flange angle was changed linearly between the A-A' cross-sectional position and the B-B' cross-sectional position. The spacing between the outer guides is 30 mm wider than the overall width of the material being rolled. In this case, L1 is 397 mm, and even if the crop length L2 is 700 mm, the A-A' cross-sectional position is greater than L1 + L2.

When manufacturing hat-shaped steel sheet piles of the above dimensions, guides (inner guide, outer guide) with shapes determined based on Figure 23 were installed and bending was performed. As a result, it was confirmed that it was possible to suppress twisting of the rolled material A during biting and improve centering performance without generating guide defects in the steady state.

The present invention can be applied to manufacturing equipment for steel sheet piles, such as hat-shaped steel sheet piles and U-shaped steel sheet piles.

LIST OF SYMBOLS 10...Roughing mill 13...First intermediate rolling mill 14...Edger rolling mill 16...Second intermediate rolling mill 17...Edger rolling mill 19...Finishing rolling mill 19a...Finishing material 20...Bending machine 22...First stand 23...Second stand 40...(First stand) Upper hole type roll 41...(First stand) Lower hole type roll 44...(First stand) Housing 45...(First stand) Hole type 50...(Second stand) Upper hole type roll 51...(Second stand) Lower hole type roll 54...(Second stand) Housing 55...(Second stand) Hole type 60...Web corresponding part 62, 63...Flange corresponding part 65, 66...Arm corresponding part 68, 69...Joint corresponding part 80 (80a, 80b)...Outer guide 90: Roller guide 95: Conveyor roller 100: Guide support portion 103: Lifting mechanism 105: Roller support portion 110: Inner guide 112: Lower guide A: Rolled material T: Rolling line (manufacturing device)

Claims (10)

A manufacturing apparatus for manufacturing a steel sheet pile by hot rolling,
The rolling mill includes a roughing mill, an intermediate rolling mill, a finishing rolling mill, and a bending mill that performs finishing rolling and bending of the rolled material continuously,
The bending machine includes one or more stands including a first stand,
A web restraining guide that restrains an upper surface of the web corresponding portion of the rolled material is provided at least upstream of the first stand of the bending machine,
A manufacturing device for steel sheet piles, characterized in that the outer width of the web restraint guide is configured to be narrower than the inner distance between the left and right flanges of the pre-deformed portion of the rolled material in a steady state at the installation position of the web restraint guide. The steel sheet pile manufacturing device according to claim 1, characterized in that the roll gap directly below the upper and lower hole type rolls of the bending machine, which face the web corresponding portion and the flange corresponding portion of the rolled material, is configured to be larger than the thickness of the web corresponding portion and the flange corresponding portion, respectively. The steel sheet pile manufacturing device according to claim 1 or 2, characterized in that a roller guide is provided as the web restraint guide, and a transport roller is provided at a position opposite the roller guide with respect to the rolling line. The steel sheet pile manufacturing device according to claim 1 or 2, characterized in that a pair of opposing upper and lower roller guides are provided on the rolling line as the web restraint guide. The steel sheet pile manufacturing device according to claim 3, characterized in that the transport roller is provided at the same position as the roller guide or at a position shifted downstream in a plan view. The steel sheet pile manufacturing device according to claim 4, characterized in that the lower roller guide of the pair of upper and lower roller guides is provided at the same position as the upper roller guide or at a position shifted downstream in a plan view. The web restraining guide is an inner guide extending in the rolling direction along the inner surface of the rolled material,
The steel sheet pile manufacturing device according to claim 1 or 2, characterized in that the cross-sectional shape of the inner guide is configured to change continuously from a cross-sectional shape approximating the rolled material after finish rolling to a cross-sectional shape of the rolled material immediately before bending. The steel sheet pile manufacturing device according to claim 7, characterized in that it is provided with at least one of a lower guide or a transport roller having a substantially flat shape extending in the rolling direction along the lower surface of the material to be rolled. The web restraint guide is provided at a distance L that satisfies the following formula (1) from the roll axis position of the grooved roll of the first stand to a position upstream of the roll axis position of the grooved roll of the first stand. The manufacturing device of the steel sheet pile according to any one of claims 1 to 8.
L>L1+L2...(1)
Here, L1 is the distance between the bending start position and the roll axis position of the grooved roll of the first stand, and L2 is the crop length of the flange corresponding portion of the rolled material. A steel sheet pile manufacturing device according to any one of claims 1 to 9, characterized in that it is provided with outer guides extending in the rolling direction on the outside of both widthwise ends of the rolled material.

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