JP7613428B2 - Rail twist correction device, rail twist correction method, and rail manufacturing method - Google Patents

Description

The present invention relates to a rail twist correction device, a twist correction method, and a rail manufacturing method.

Generally, rails are manufactured by hot rolling, in which a rectangular cross-section bloom is used as the material, and the cross-sectional shape is formed by caliber rolling into the product shape.
Here, after hot rolling, the rail is straightened by a roller straightener to straighten the rail for bending and warping. If the rail has a shape defect after straightening by the roller straightener, the rail is subjected to cold press straightening to correct the shape defect.
Conventionally, a method for straightening a warp in a rail is known, for example, as disclosed in Japanese Patent Application Laid-Open No. 2003-233696.

The rail straightening method shown in Patent Document 1 involves cooling the rail, applying a tensile force to the rail in the longitudinal direction, and applying a bending moment such that the head of the rail faces outward or inward when 70% or more of the entire cross section has yielded.
According to the rail straightening method disclosed in Patent Document 1, it is possible to manufacture rails with little bending or warping, very low residual stress, and excellent wear resistance and fracture resistance.

JP 2011-79008 A

After a rail is hot-rolled into a product shape and then cooled, shape defects such as warping, bending, and also twisting may occur.
Here, a general shape of a rail will be described with reference to FIG. 11. The rail 100 extends in the width direction (the direction indicated by the arrow x in FIG. 11), the up-down direction (the direction indicated by the arrow z in FIG. 11), and the longitudinal direction (the direction perpendicular to the paper surface in FIG. 11, the direction indicated by the arrow y in FIG. 12). The rail 100 includes a head 101, a body 102, and a foot 103. The foot 103 extends in an elongated manner in the width direction, and includes a bottom surface 103a. The body 102 extends in an elongated manner upward from the upper surface of the center of the width direction of the foot 103. The head 101 is provided on the upper part of the body 102, and includes a top surface 101a that extends linearly in the width direction. The head 101 also has a left head side surface 101b extending downward from the left side of the parietal surface 101a in the width direction, and a right head side surface 101c extending downward from the right side of the parietal surface 101a in the width direction. A left submandibular surface 101d is provided from the left head side surface 101b in the width direction toward the left side surface of the abdomen 102, and a right submandibular surface 101e is provided from the right head side surface 101c in the width direction toward the right side surface of the abdomen 102.

Regarding rail twist, this refers to a phenomenon in which the rail 100 twists along the longitudinal direction of the rail 100, as shown in Figure 12, and the tip 103b of the foot portion 103 of the rail 100 on one widthwise side (the left side in Figure 12) gradually rises up when viewed from the front side (the side where the head portion 101, the body portion 102, and the foot portion 103 of the rail 100 are visible).
Regarding the amount of twist of the rail, as shown in Fig. 13, the rail 100 is placed on a flat reference plane 111 of a surface plate 110 with the bottom surface 103a of the foot portion 103 facing down. The size of the "gap" δ between the bottom surface of the tip 103c of the foot portion 103 on one widthwise side (the right side in Fig. 13) of the rail 100 and the reference plane 111 is defined as the "amount of twist" δ of the rail 100. This "amount of twist" of the rail 100 is generally controlled at two locations, the longitudinal leading end region and the longitudinal trailing end region of the rail 100.

However, as described above, the rail straightening method disclosed in Patent Document 1 is for straightening the warp of the rail, but is not for straightening the twist of the rail. Therefore, even if the straightening method disclosed in Patent Document 1 is applied to straighten the twist of the rail, the twist of the rail is not properly straightened.
Therefore, the present invention has been made to solve the above-mentioned problems in the conventional art, and an object of the present invention is to provide a device for straightening twist of a rail, a method for straightening twist of a rail, and a method for manufacturing a rail, which are capable of accurately straightening twist of a rail.

In order to solve the above-mentioned problems, a rail twist straightening device according to one embodiment of the present invention is a rail twist straightening device that corrects twists in a rail extending in the longitudinal direction, and comprises, on one side of the longitudinal direction of the rail, a first die that presses the foot portion of the rail and a second die that presses the head portion of the rail, and, on the other side of the longitudinal direction of the rail, a third die that presses the head portion of the rail and a fourth die that presses the foot portion of the rail, wherein the first die and the third die are disposed on one side of the width direction of the rail, and the second die and the fourth die are disposed on the other side of the width direction of the rail.
Furthermore, a method for straightening a rail's twist according to another aspect of the present invention is a method for straightening a twist of a rail extending in the longitudinal direction, which comprises the steps of: on one side of the longitudinal direction of the rail, pressing a foot portion of the rail with a first die arranged on one side of the width direction of the rail, and pressing a head portion of the rail with a second die arranged on the other side of the width direction of the rail; and on the other side of the longitudinal direction of the rail, pressing the head portion of the rail with a third die arranged on one side of the width direction of the rail, and pressing a foot portion of the rail with a fourth die arranged on the other side of the width direction of the rail.

The rail manufacturing method according to another aspect of the present invention includes a twist correction process for correcting the twist of the rail by the above-mentioned rail twist correction method.

The rail twist correction device, twist correction method, and rail manufacturing method of the present invention allow for accurate correction of rail twists.

FIG. 1 is a plan view of a rail twist straightening device according to a first embodiment of the present invention. This is a cross-sectional view taken along line A-A' in Figure 1. This is a cross-sectional view taken along line B-B' in Figure 1. 1. FIG. 4 is a diagram for explaining a fitting state of a second die to a second holder in the twist straightening device shown in FIG. FIG. 11 is a plan view of a rail twist straightening device according to a first modified example. FIG. 11 is a plan view of a rail twist straightening device according to a second modified example. 2 is a cross-sectional view similar to the cross-sectional view taken along line A-A' in FIG. 1, showing a rail twist straightening device according to a second embodiment of the present invention. 2 is a cross-sectional view similar to the cross-sectional view taken along line B-B' in FIG. 1, showing a rail twist straightening device according to a second embodiment of the present invention. 1 , in a rail twist straightening device according to a third embodiment of the present invention. FIG. FIG. 11 is a cross-sectional view similar to the cross-sectional view taken along line B-B' in FIG. 1, showing a rail twist straightening device according to a third embodiment of the present invention. FIG. 4 is a front view for explaining each part of the rail. FIG. 13 is a diagram for explaining twisting of a rail. FIG. 13 is a diagram for explaining the amount of twist of a rail.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments shown below are merely examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention is not limited to the following embodiments in terms of the materials, shapes, structures, arrangements, etc. of the components.
In addition, the drawings are schematic, and therefore, it should be noted that the relationship between thickness and planar dimensions, ratios, etc. may differ from the actual relationship between thickness and planar dimensions, and the drawings may include parts in which the relationship between dimensions and ratios differ from one another.
First Embodiment
FIG. 1 shows a plan view of a rail twist straightening device according to a first embodiment of the present invention.

The rail twist straightening device 1 shown in Fig. 1 is for straightening twists in a rail 100 shown in Fig. 11 after hot rolling into a product shape and cooling. The twist straightening device 1 is equipped with a first die 10 for pressing a foot portion 103 of the rail 100 and a second die 20 for pressing a head portion 101 of the rail 100 on one side (the upper side in Fig. 1) of the longitudinal direction of the rail 100 (the direction indicated by the arrow y).
In addition, the twist straightening device 1 is equipped with a third die 30 that presses the head portion 101 of the rail 100 and a fourth die 40 that presses the foot portion 103 of the rail 100 on the other side of the longitudinal direction of the rail 100 (the lower side in Figure 1).

The first mold 10 and the third mold 30 are arranged on one side (left side in Figure 1) of the width direction of the rail 100 (direction indicated by arrow x), and the second mold 20 and the fourth mold 40 are arranged on the other side (right side in Figure 1) of the width direction of the rail 100.
In this embodiment, the rail 100 is transported by table rollers (not shown) with the longitudinal tip of the rail 100 (the upper end in FIG. 1) at the leading edge, and is loaded into the twist straightening device 1 from the side where the third die 30 and the fourth die 40 are arranged (the lower side in FIG. 1).
Then, in the longitudinal tip end region of the rail 100, the foot 103 of the rail 100 is pressed by the first die 10 on one longitudinal side of the rail 100, and the head 101 of the rail 100 is pressed by the second die 20. Moreover, on the other longitudinal side of the rail 100, the head 101 of the rail 100 is pressed by the third die 10, and the foot 103 of the rail 100 is pressed by the fourth die 40. This corrects the twist of the rail 100 in the longitudinal tip end region of the rail 100.

The rail 100, whose twist has been corrected in the longitudinal tip region, is fed in the longitudinal direction (from the lower side to the upper side in FIG. 1) by the table roller. Then, in the longitudinal rear end region of the rail 100, the first die 10 presses the foot 103 of the rail 100 on one side of the longitudinal direction of the rail 100, and the second die 20 presses the head 101 of the rail 100. Also, on the other longitudinal side of the rail 100, the third die 10 presses the head 101 of the rail 100, and the fourth die 40 presses the foot 103 of the rail 100. This corrects the twist of the rail 100 in the longitudinal rear end region of the rail 100.

The reason why the rail 100 is straightened in the longitudinal leading end region and the longitudinal rear end region by the rail twist straightening device 1 according to the first embodiment is as follows: That is, when a twist occurs in the rail 100, the amount of twist becomes more significant in the longitudinal leading end region and the longitudinal rear end region of the rail 100 compared to other regions of the rail 100.
Here, the first die 10 and the second die 20 are arranged to face each other in the width direction of the rail 100 at a first position a on one side in the longitudinal direction of the rail 100. Moreover, the third die 30 and the fourth die 40 are arranged to face each other in the width direction of the rail 100 at a second position b on the other side in the longitudinal direction of the rail 100. The distance between the first position a and the second position b is set to about 1 to 2 m in this embodiment.

Specifically, with regard to the first die 10, as shown in Figures 1 and 2, when correcting twist in the rail 100, the tip 103b on the left side in the width direction of the foot portion 103 of the rail 100 is pressed at a first position a on one side of the longitudinal direction of the rail 100.
1 and 2, the first die 10 is held inside the first holder 11, and the first holder 11 is disposed on the inside in the width direction with respect to the first plate 15 and is installed so as to be vertically movable with respect to the inner surface of the first plate 15. The first holder 11 that holds the first die 10 is disposed so as to be vertically movable with respect to the first plate 15. As a result, when the first die 10 presses the foot 103 of the rail 100, the first holder 11 moves vertically with respect to the first plate 15 due to the reaction force. Therefore, no load is applied to members such as a fall prevention plate 12 and a connection bolt 13, which will be described later, that prevent the first holder 11 from falling, and damage to these members can be prevented.

Further, a fall prevention plate 12 that is placed on the first plate 15 and prevents the first holder 11 from falling is fixed to the upper surface of the first holder 11 by a connecting bolt 13. This makes it possible to prevent the first holder 11 from falling off the first plate 15.
However, the fall prevention plate 12 fixed to the first holder 11 and the upper surface of the first plate 15 are connected by a metal spring 14 serving as an elastic body that maintains the vertical position of the first holder 11.
As a result, when the first holder 11 moves up and down relative to the first plate 15, the vertical movement range of the first holder 11 can be limited to a predetermined distance while the vertical movement of the first holder 11 is absorbed by the metal spring 14. As a result, the range of the vertical position of the first mold 10 relative to the foot portion 103 of the rail 100 can be limited, and appropriate pressing of the first mold 10 against the foot portion 103 of the rail 100 can be ensured.

Suppose that the fall prevention plate 12 fixed to the first holder 11 is not connected to the upper surface of the first plate 15 by the metal spring 14. In that case, when the first holder 11 moves up and down relative to the first plate 15, the range of the up-down position of the first mold 10 relative to the foot 103 of the rail 100 cannot be limited, and appropriate pressure on the foot 103 of the rail 100 of the first mold 10 cannot be guaranteed.
The metal spring 14 may be either a compression spring or a tension spring, and although it depends on the weight of the first holder 11 and the first mold 10, it is preferable that the spring constant is about 100 to 1000 N/mm and the stroke is about ±10 mm in the vertical direction.

Next, the second die 20 will be specifically described. As shown in Figures 1 and 2, the second die 20 presses the head side surface 101c on the right side in the width direction of the head 101 of the rail 100 at a first position a on one side in the longitudinal direction of the rail 100 during twist straightening of the rail 100.
1 and 2, the second die 20 is held inside the second holder 21, and the second holder 21 is disposed on the inside in the width direction of the second plate 25 and is installed so as to be vertically movable relative to the inner surface of the second plate 25. The second holder 21 that holds the second die 20 is disposed so as to be vertically movable relative to the second plate 25. As a result, when the second die 20 presses the head 101 of the rail 100, the second holder 21 moves vertically relative to the second plate 25 due to the reaction force. Therefore, no load is applied to members such as a fall prevention plate 22 and a connection bolt 23, which will be described later, that prevent the second holder 21 from falling, and damage to these members can be prevented.

The holding of the second mold 20 by the second holder 21 will be described with reference to FIG. 4. The second mold 20 is formed in a T-shape when viewed from the top. The second mold 20 includes a rectangular mold body 20a extending in the vertical direction and a protruding portion 20b protruding in the width direction (vertical direction in FIG. 4) from both sides of the mold body 20a in the width direction on the side of the mold body 20a. Note that, although the shape of the mold body 20a is shown as a rectangle in FIG. 4, the shape of the mold body 20a is not limited to a rectangle, and the corners may be rounded or the tip may be formed into an arc shape.
A dovetail groove into which the T-shaped second die 20 is fitted is formed on the inner surface of the second holder 21. This dovetail groove has a first groove portion 21a into which the die body 20a is fitted and a second groove portion 21b into which the protrusion 20b is fitted. The dovetail groove is formed so as to penetrate the second holder 21 in the vertical direction. The T-shaped second die 20 is fitted into the dovetail groove formed on the inner surface of the second holder 21 from above or below the second holder 21. Then, a spacer (not shown) is inserted from below the second holder 21 into the dovetail groove into which the second die is fitted. This prevents the second die 20 already fitted into the dovetail groove from falling out downward and positions the second die 20 in the vertical direction. At this time, the vertical position of the second die 20 is set to a position where it can press the head side surface 101c on the right side in the width direction of the head 101 of the rail 100. As a result, the second mold 20 is held by the second holder 21. The vertical position of the second mold 20 can be adjusted by appropriately changing the vertical position of the spacer according to the size of the rail 100. It is not necessarily required to prevent the second mold 20 engaged in the dovetail groove from slipping out upward, and the vertical position may be determined by the weight of the mold 20 itself, or a spacer may be disposed above the mold 20 to prevent it from slipping out.

The first mold 10, the third mold 30, and the fourth mold 40 have the same configuration as the second mold 20. That is, the mold shape can be a rectangular shape, a shape with rounded corners, or a shape with an arc-shaped tip. There is no need to make the sizes of these molds the same. The first holder 11 holds the first mold 10, the third holder 31 holds the third mold 30, and the fourth holder 41 holds the fourth mold 40 in the same manner as the second holder 21 holds the second mold 20. When the first holder 11 holds the first mold 10, the first mold 10 is positioned in the up-down direction so that it can press the tip 103b on the left side of the width direction of the foot 103 of the rail 100. In addition, when the third holder 31 holds the third die 30, the vertical position of the third die 30 is set to a position where it can press the head side surface 101b on the left side in the width direction of the head 101 of the rail 100. Furthermore, the vertical position of the fourth die 40 is set to a position where it can press the tip 103c on the right side in the width direction of the foot 103 of the rail 100.

Further, a fall prevention plate 22 that is placed on the second plate 25 and prevents the second holder 21 from falling is fixed to the upper surface of the second holder 21 by a connecting bolt 23. This makes it possible to prevent the second holder 21 from falling off the second plate 25.
However, the fall prevention plate 22 fixed to the second holder 21 and the upper surface of the second plate 25 are connected by a metal spring 24 as an elastic body that maintains the vertical position of the second holder 21, similar to the first holder 11.
As a result, when the second holder 21 moves up and down relative to the second plate 25, the vertical movement range of the second holder 21 can be limited to a predetermined distance while the vertical movement of the second holder 21 is absorbed by the metal spring 24. As a result, the range of the vertical position of the second die 20 relative to the head 101 of the rail 100 can be limited, and appropriate pressing of the second die 20 against the head 101 of the rail 100 can be ensured.

The metal spring 24, like the metal spring 14, may be either a compression spring or a tension spring, and depending on the weight of the second holder 21 and the second mold 20, it is preferable that the spring constant be approximately 100 to 1000 N/mm and that the stroke be approximately ±10 mm in the vertical direction.
Further, the third die 30 will be specifically described. As shown in Figures 1 and 3, the third die 30 presses the head side surface 101b on the left side in the width direction of the head 101 of the rail 100 at the second position b on the other side in the longitudinal direction of the rail 100 during twist correction of the rail 100.
1 and 3, the third die 30 is held by a third holder 31, which is disposed on the inside in the width direction relative to the third plate 35 and is installed so as to be vertically movable relative to the inner surface of the third plate 35. The third holder 31 that holds the third die 30 is disposed so as to be vertically movable relative to the third plate 35. As a result, when the third die 30 presses the head 101 of the rail 100, the third holder 31 moves vertically relative to the third plate 35 due to the reaction force. Therefore, no load is applied to members such as a fall prevention plate 32 and a connection bolt 33, which will be described later, that prevent the third holder 31 from falling, and damage to these members can be prevented.

Further, a fall prevention plate 32 that is placed on the third plate 35 and prevents the third holder 31 from falling is fixed to the upper surface of the third holder 31 by a connecting bolt 33. This makes it possible to prevent the third holder 31 from falling off the third plate 35.
However, the fall prevention plate 32 fixed to the third holder 31 and the upper surface of the third plate 35 are connected by a metal spring 34, which acts as an elastic body that maintains the vertical position of the third holder 31, in the same manner as the first holder 11.
As a result, when the third holder 31 moves up and down relative to the third plate 35, the vertical movement range of the third holder 31 can be limited to a predetermined distance while the vertical movement of the third holder 31 is absorbed by the metal spring 34. As a result, the range of the vertical position of the third die 30 relative to the head 101 of the rail 100 can be limited, and appropriate pressing of the third die 30 against the head 101 of the rail 100 can be ensured.

The metal spring 34, like the metal spring 14, may be either a compression spring or a tension spring, and depending on the weight of the third holder 31 and the third mold 30, it is preferable that the spring constant be approximately 100 to 1000 N/mm and that the stroke be approximately ±10 mm in the vertical direction.
Next, the fourth die 40 will be specifically described. As shown in Figures 1 and 3, the fourth die 40 presses the tip 103c on the right side in the width direction of the foot portion 103 of the rail 100 at the second position b on the other side in the longitudinal direction of the rail 100 when straightening the twist of the rail 100.
1 and 3, the fourth die 40 is held by a fourth holder 41, and the fourth holder 41 is disposed on the inner side of the fourth plate 45 in the width direction and is installed so as to be vertically movable with respect to the inner surface of the fourth plate 45. The fourth holder 41 that holds the fourth die 40 is disposed so as to be vertically movable with respect to the fourth plate 45. As a result, when the fourth die 40 presses the foot 103 of the rail 100, the reaction force causes the fourth holder 41 to move vertically with respect to the fourth plate 45. Therefore, no load is applied to members such as a fall prevention plate 42 and a connection bolt 43, which will be described later, that prevent the fourth holder 41 from falling, and damage to these members can be prevented.

Further, a fall prevention plate 42 that is placed on the fourth plate 45 and prevents the fourth holder 41 from falling is fixed to the upper surface of the fourth holder 41 by a connecting bolt 43. This makes it possible to prevent the fourth holder 41 from falling off the fourth plate 45.
However, the fall prevention plate 42 fixed to the fourth holder 41 and the upper surface of the fourth plate 45 are connected by a metal spring 44, which acts as an elastic body that maintains the vertical position of the fourth holder 41, in the same manner as the first holder 11.
As a result, when the fourth holder 41 moves up and down relative to the fourth plate 45, the vertical movement range of the fourth holder 41 can be limited to a predetermined distance while the vertical movement of the fourth holder 41 is absorbed by the metal spring 44. As a result, the range of the vertical position of the fourth die 40 relative to the foot portion 103 of the rail 100 can be limited, and appropriate pressing of the fourth die 40 against the foot portion 103 of the rail 100 can be ensured.

The metal spring 44, like the metal spring 14, may be either a compression spring or a tension spring, and depending on the weight of the fourth holder 41 and the fourth mold 40, it is preferable that the spring constant be approximately 100 to 1000 N/mm and that the stroke be approximately ±10 mm in the vertical direction.
1, the first plate 15 and the third plate 35 are integrally formed as a fixed-side plate 50. The second plate 25 and the fourth plate 45 are integrally formed as a moving-side plate 60. A pressing cylinder 70 is connected to the moving-side plate 60, which moves the moving-side plate 60 in a direction to approach the fixed-side plate 50 and moves the moving-side plate 60 away from the fixed-side plate 50 after approaching the fixed-side plate 50.

The first die 10 presses the foot 103 (the tip 103b on the left side in the width direction) of the rail 100, and the second die 20 presses the head 101 (the head side surface 101c on the right side in the width direction) of the rail 100 when the moving side plate 60 moves in a direction approaching the fixed side plate 50 by the pressing cylinder 70 when correcting the twist of the rail 100. In other words, when correcting the twist of the rail 100, the pressing cylinder 70 moves the second die 20 in a direction approaching the first die 10. This achieves the pressing of the foot 103 of the rail 100 by the first die 10, and the pressing of the head 101 of the rail 100 by the second die 20.

In addition, when the movable plate 60 is moved in a direction approaching the fixed plate 50 by the pressing cylinder 70, the third die 30 presses the head 101 (head side surface 101b on the left side in the width direction) of the rail 100, and the fourth die 40 presses the foot 103 (tip 103c on the right side in the width direction) of the rail 100 at the same time. In other words, when correcting the twist of the rail 100, the fourth die 40 moves in a direction approaching the third die 30 by the pressing cylinder 70. As a result, the third die 30 presses the head 101 of the rail 100, and the fourth die 40 presses the foot 103 of the rail 100 at the same time.
That is, the pressing cylinder 70 moves the moving side plate 60 in a direction approaching the fixed side plate 50. Then, the second holder 21 and the second die 20 installed on the second plate 25 constituting the moving side plate 60 also move in a direction approaching the fixed side plate 50 (first die 10) (from the other side (right side) in the width direction to one side (left side) in the width direction). This achieves pressing the foot 103 (the tip 103b on the left side in the width direction) of the rail 100 by the first die 10, and pressing the head 101 (the head side surface 101c on the right side in the width direction) of the rail 100 by the second die 20. Also, the pressing cylinder 70 moves the moving side plate 60 in a direction approaching the fixed side plate 50. Then, the fourth holder 41 and the fourth die 40 installed on the fourth plate 45 also move in a direction approaching the fixed side plate 50 (third die 30) at the same time. This results in the third die 30 pressing the head 101 (head side surface 101b on the left side in the width direction) of the rail 100, and the fourth die 40 pressing the foot 103 (tip 103c on the right side in the width direction) of the rail 100.

In addition, when the moving side plate 60 approaches the fixed side plate 50, the pressing cylinder 70 moves the moving side plate 60 in a direction away from the fixed side plate 50. Then, the second holder 21 and the second die 20 installed on the second plate 25 constituting the moving side plate 60 also move in a direction away from the fixed side plate 50 (first die 10) (from one side (left) in the width direction to the other side (right) in the width direction). This releases the first die 10 from pressing the foot 103 (tip 103b on the left side in the width direction) of the rail 100, and the second die 20 from pressing the head 101 (head side surface 101c on the right side in the width direction) of the rail 100. In addition, when the moving side plate 60 approaches the fixed side plate 50, the pressing cylinder 70 moves the moving side plate 60 in a direction away from the fixed side plate 50. Then, the fourth holder 41 and the fourth die 40 installed on the fourth plate 45 also move simultaneously in a direction away from the fixed side plate 50 (third die 30). This releases the third die 30 from pressing the head 101 (head side surface 101b on the left side in the width direction) of the rail 100, and the fourth die 40 from pressing the foot 103 (tip 103c on the right side in the width direction) of the rail 100.

Next, a method for straightening the twist of the rail 100 using the rail twist straightening device 1 shown in Figs. 1 to 3 will be described.
First, when the twist of the rail 100 is corrected, the rail 100, which has been hot-rolled into a product shape and cooled, is transported by table rollers (not shown) with the bottom surface 103a of the foot portion 103 facing downward. In this embodiment, the rail 100 is transported by table rollers (not shown) with the longitudinal tip of the rail 100 (upper end in FIG. 1) at the head, and is loaded into the twist straightening device 1 from the side where the third die 30 and the fourth die 40 are arranged (lower side in FIG. 1). The longitudinal tip side region of the rail 100 is located between the first die 10 and the third die 30 and the second die 20 and the fourth die 40 of the twist straightening device 1.

As a result, the first mold 10 and the third mold 30 are arranged on one side (left side in FIG. 1) of the width direction (direction indicated by arrow x) of the rail 100 in the longitudinal tip side region of the rail 100. The second mold 20 and the fourth mold 40 are arranged on the other side (right side in FIG. 1) of the width direction of the rail 100. The first mold 10 and the second mold 20 are arranged to face each other in the width direction of the rail 100 at a first position a on one side of the longitudinal direction of the rail 100 (upper side in FIG. 1) in the longitudinal tip side region of the rail 100. The third mold 30 and the fourth mold 40 are arranged to face each other in the width direction of the rail 100 at a second position b on the other side of the longitudinal direction of the rail 100 (lower side in FIG. 1).

Next, the movable plate 60 is moved in a direction approaching the fixed plate 50 by the pressing cylinder 70 .
As a result, the second holder 21 and second die 20 mounted on the second plate 25 constituting the movable side plate 60 move in a direction approaching the fixed side plate 50 (from the other side (right side) in the width direction to one side (left side) in the width direction). As a result, on one side of the longitudinal direction of the rail 100 (the upper side in FIG. 1 ), the first die 10 arranged on one side (left side) in the width direction of the rail 100 presses the foot 103 (tip 103b on the left side in the width direction) of the rail 100. At the same time, the second die 20 arranged on the other side (right side) in the width direction of the rail 100 presses the head 101 (head side surface 101c on the right side in the width direction) of the rail 100.

The fourth holder 41 and fourth die 40 mounted on the fourth plate 45 constituting the movable plate 60 also move in a direction approaching the fixed plate 50 (from the other widthwise side (right side) to one widthwise side (left side)). As a result, on the other longitudinal side (lower side in FIG. 1 ) of the rail 100, the third die 30 arranged on one widthwise side (left side) of the rail 100 presses the head 101 (head side surface 101b on the left side in the widthwise direction) of the rail 100. At the same time, the fourth die 40 arranged on the other widthwise side (right side) of the rail 100 presses the foot 103 (tip 103c on the right side in the widthwise direction) of the rail 100.
This corrects the twist of the rail 100 in the longitudinal tip region of the rail 100 .

Next, the moving plate 60 is moved in a direction away from the fixed plate 50 by the pressing cylinder 70 .
As a result, the second holder 21 and second die 20 installed on the second plate 25 that constitutes the movable side plate 60 move in a direction away from the fixed side plate 50 (from one side (left) in the width direction to the other side (right) in the width direction). This releases the first die 10 from pressing against the foot 103 (tip 103b on the left side in the width direction) of the rail 100. At the same time, the second die 20 releases the pressing against the head 101 (head side surface 101c on the right side in the width direction) of the rail 100.

Additionally, the fourth holder 41 and fourth die 40 installed on the fourth plate 45 constituting the movable side plate 60 also move in a direction away from the fixed side plate 50 (from one side (left) in the width direction to the other side (right) in the width direction). This releases the third die 30 from pressing the head 101 (head side surface 101b on the left side in the width direction) of the rail 100. At the same time, the fourth die 40 releases the fourth die 40 from pressing the foot 103 (tip 103c on the right side in the width direction) of the rail 100.
Next, the rail 100, whose twist has been corrected in the longitudinal tip region, is fed forward in the longitudinal direction (from the lower side to the upper side in FIG. 1 ) by the table rollers. Then, the longitudinal rear end region of the rail 100 is positioned between the first and third dies 10 and the second and fourth dies 20 and 40 of the twist straightening device 1.

As a result, the first mold 10 and the third mold 30 are arranged on one side (left side in FIG. 1) of the width direction (direction indicated by arrow x) of the rail 100 in the longitudinal rear end region of the rail 100. The second mold 20 and the fourth mold 40 are arranged on the other side (right side in FIG. 1) of the width direction of the rail 100. The first mold 10 and the second mold 20 are arranged to face each other in the width direction of the rail 100 at a first position a on one side (upper side in FIG. 1) of the longitudinal direction of the rail 100 in the longitudinal rear end region of the rail 100. The third mold 30 and the fourth mold 40 are arranged to face each other in the width direction of the rail 100 at a second position b on the other side (lower side in FIG. 1) of the longitudinal direction of the rail 100.

Next, the movable plate 60 is moved in a direction approaching the fixed plate 50 by the pressing cylinder 70 .
As a result, the second holder 21 and second die 20 installed on the second plate 20 constituting the movable side plate 60 move in a direction approaching the fixed side plate 50 (from the other side (right side) in the width direction to one side (left side) in the width direction). As a result, on one side of the longitudinal direction of the rail 100 (the upper side in FIG. 1 ), the first die 10 arranged on one side (left side) in the width direction of the rail 100 presses the foot 103 (the tip 103b on the left side in the width direction) of the rail 100. At the same time, the second die 20 arranged on the other side (right side) in the width direction of the rail 100 presses the head 101 (head side surface 101c on the right side in the width direction) of the rail 100.

The fourth holder 41 and fourth die 40 installed on the fourth plate 40 constituting the movable plate 60 also move in a direction approaching the fixed plate 50 (from the other widthwise side (right side) to one widthwise side (left side)). As a result, on the other longitudinal side (lower side in FIG. 1 ) of the rail 100, the third die 30 arranged on one widthwise side (left side) of the rail 100 presses the head 101 (head side surface 101b on the left side in the widthwise direction) of the rail 100. At the same time, the fourth die 40 arranged on the other widthwise side (right side) of the rail 100 presses the foot 103 (tip 103c on the right side in the widthwise direction) of the rail 100.
This straightens out any twist in the rail 100 at the longitudinal rear end region of the rail 100 .

Then, the pressing cylinder 70 moves the movable plate 60 in a direction away from the fixed plate 50, and the first die 10 releases the pressure applied to the foot 103 (the tip 103b on the left side in the width direction) of the rail 100. At the same time, the second die 20 releases the pressure applied to the head 101 (the head side surface 101c on the right side in the width direction) of the rail 100. At the same time, the third die 30 releases the pressure applied to the head 101 (the head side surface 101b on the left side in the width direction) of the rail 100. At the same time, the fourth die 40 releases the pressure applied to the foot 103 (the tip 103c on the right side in the width direction) of the rail 100.
This completes the straightening of the twist of the rail 100 using the rail twist straightening device 1.

The manufacturing method of the rail 100 includes a twist straightening step of straightening the twist of the rail 100 by a twist straightening method using the rail twist straightening device 1.
Thus, the twist straightening device 1 of the first embodiment includes a first die 10 for pressing the foot 103 of the rail 100 and a second die 20 for pressing the head 101 of the rail 100 on one side (upper side in FIG. 1) of the longitudinal direction (direction indicated by arrow y) of the rail 100. The twist straightening device 1 also includes a third die 30 for pressing the head 101 of the rail 100 and a fourth die 40 for pressing the foot 103 of the rail 100 on the other side (lower side in FIG. 1) of the longitudinal direction of the rail 100. The first die 10 and the third die 30 are disposed on one side (left side in FIG. 1) of the width direction (direction indicated by arrow x) of the rail 100. The second die 20 and the fourth die 40 are disposed on the other side (right side in FIG. 1) of the width direction of the rail 100.

This allows the twisting of the rail 100 to be accurately corrected.
Furthermore, according to the rail twist straightening device 1 of the first embodiment, the first die 10 and the second die 20 are arranged to face each other in the width direction (indicated by arrow x) of the rail 100 at a first position a on one side (upper side in Fig. 1) of the longitudinal direction (direction indicated by arrow y) of the rail 100. Moreover, the third die 30 and the fourth die 40 are arranged to face each other in the width direction of the rail 100 at a second position b on the other side (lower side in Fig. 1) of the longitudinal direction of the rail 100.
This allows the first to fourth dies 10 to 40 to be positioned at appropriate positions, making it possible to efficiently correct any twisting of the rail 100.

Moreover, according to the rail twist straightening device 1 according to the first embodiment, the first to fourth dies 10 to 40 are held by the first to fourth holders 11 to 41, respectively. The first to fourth holders 11 to 41 are installed so as to be movable up and down relative to the first to fourth plates 15 to 45, respectively.
As a result, when the first die 10 presses the foot 103 of the rail 100, the reaction force causes the first holder 11 to move up and down relative to the first plate 15. Therefore, no load is applied to the fall prevention plate 12 and the connection bolt 13, which prevent the first holder 11 from falling, and damage to these members can be prevented. Furthermore, when the second die 20 presses the head 101 of the rail 100, the reaction force causes the second holder 21 to move up and down relative to the second plate 25. Therefore, no load is applied to the fall prevention plate 22 and the connection bolt 23, which prevent the second holder 21 from falling, which will be described later, and damage to these members can be prevented. Furthermore, when the third die 30 presses the head 101 of the rail 100, the reaction force causes the third holder 31 to move up and down relative to the third plate 35. Therefore, no load is applied to components such as the fall prevention plate 32 and the connection bolt 33, which will be described later, which prevent the third holder 31 from falling, and damage to these components can be prevented. Also, when the fourth die 40 presses the foot 103 of the rail 100, the reaction force causes the fourth holder 41 to move up and down relative to the fourth plate 45. Therefore, no load is applied to components such as the fall prevention plate 42 and the connection bolt 43, which prevent the fourth holder 41 from falling, and damage to these components can be prevented.

Furthermore, according to the rail twist straightening device 1 of the first embodiment, the first to fourth holders 11 to 41 are provided with anti-drop plates 12 to 42 on their upper surfaces, which are placed on the first to fourth plates 15 to 45 and prevent the first to fourth holders 11 to 41 from falling.
This makes it possible to prevent the first to fourth holders 11 to 41 from falling off the first to fourth plates 15 to 45, respectively.
Furthermore, according to the rail twist straightening device 1 of the first embodiment, the fall prevention plates 12 to 42 of each of the first to fourth holders 11 to 41 are connected to the upper surfaces of the first to fourth plates 15 to 45 by metal springs 14 to 44 which serve as elastic bodies that maintain the vertical positions of each of the first to fourth holders 11 to 41.

As a result, when the first holder 11 moves up and down relative to the first plate 15, the metal spring 14 can absorb the up and down movement of the first holder 11 while limiting the up and down movement range of the first holder 11 to a predetermined distance. As a result, the range of the up and down position of the first mold 10 relative to the foot 103 of the rail 100 can be limited, and appropriate pressing against the foot 103 of the rail 100 of the first mold 10 can be ensured. Also, when the second holder 21 moves up and down relative to the second plate 25, the metal spring 24 can absorb the up and down movement of the second holder 21 while limiting the up and down movement range of the second holder 21 to a predetermined distance. As a result, the range of the up and down position of the second mold 20 relative to the head 101 of the rail 100 can be limited, and appropriate pressing against the head 101 of the rail 100 of the second mold 20 can be ensured. In addition, when the third holder 31 moves up and down relative to the third plate 35, the metal spring 34 can absorb the vertical movement of the third holder 31 while limiting the vertical movement range of the third holder 31 to a predetermined distance. This allows the range of the vertical position of the third mold 30 relative to the head 101 of the rail 100 to be limited, and appropriate pressure can be ensured against the head 101 of the rail 100 of the third mold 30. Furthermore, when the fourth holder 41 moves up and down relative to the fourth plate 45, the metal spring 44 can absorb the vertical movement of the fourth holder 41 while limiting the vertical movement range of the fourth holder 41 to a predetermined distance. This allows the range of the vertical position of the fourth mold 40 relative to the foot 103 of the rail 100 to be limited, and appropriate pressure can be ensured against the foot 103 of the rail 100 of the fourth mold 40.

Furthermore, according to the rail twist straightening device 1 of the first embodiment, the first plate 15 and the third plate 35 are integrally formed as a fixed side plate 50, and the second plate 25 and the fourth plate 45 are integrally formed as a movable side plate 60 that is moved by the pressing cylinder 70.
The first die 10 presses the foot 103 of the rail 100, and the second die 20 presses the head 101 of the rail 100 when the pressing cylinder 70 moves the movable plate 60 (second die 2) in a direction approaching the fixed plate 50 (first die 10) during the correction of twist of the rail 100. The third die 30 presses the head 101 of the rail 100, and the fourth die 40 presses the foot 103 of the rail 100 when the pressing cylinder 70 moves the movable plate 60 (fourth die 40) in a direction approaching the fixed plate 50 (third die 30) during the correction of twist of the rail 100. The release of the pressure applied to the foot 103 of the rail 100 by the first die 10 and the release of the pressure applied to the head 101 of the rail 100 by the second die 20 are achieved when the pressing cylinder 70 moves the moving side plate 60 (second die 20) in a direction away from the fixed side plate 50 (first die 10). The release of the pressure applied to the head 101 of the rail 100 by the third die 30 and the release of the pressure applied to the foot 103 of the rail 100 by the fourth die 40 are also achieved when the pressing cylinder 70 moves the moving side plate 60 (fourth die 40) in a direction away from the fixed side plate 50 (third die 30).

Therefore, when correcting the twist of the rail 100, there is no need to move the first die 10, the second die 20, the third die 30, and the fourth die 40 independently, and the twist of the rail 100 can be corrected simply by moving the moving side plate 60 with the pressing cylinder 70.
According to the method for straightening a rail twist according to the first embodiment, the foot 103 of the rail 100 is pressed by the first die 10 arranged on one side (upper side in FIG. 1) of the rail 100 in the width direction (direction indicated by arrow x) at one side (upper side in FIG. 1) of the rail 100 in the longitudinal direction (direction indicated by arrow y). The head 101 of the rail 100 is pressed by the second die 20 arranged on the other side (right side in FIG. 1) of the rail 100 in the width direction. The head 101 of the rail 100 is pressed by the third die 30 arranged on one side (left side in FIG. 1) of the rail 100 in the width direction at the other side (lower side in FIG. 1) of the rail 100 in the longitudinal direction. The foot 103 of the rail 100 is pressed by the fourth die 40 arranged on the other side (right side in FIG. 1) of the rail 100 in the width direction.

This allows the twisting of the rail 100 to be accurately corrected.
(First Modification)
Next, a rail twist straightening device according to a first modified example will be described with reference to Fig. 5. Fig. 5 is a plan view of the rail twist straightening device according to the first modified example. In Fig. 5, the same members as those shown in Fig. 1 are given the same reference numerals, and their description may be omitted.
The rail twist straightening device 1 according to the first modified example shown in Fig. 5, like the rail twist straightening device 1 according to the first embodiment shown in Fig. 1, is adapted to straighten twists in a rail 100 shown in Fig. 11 after hot rolling into a product shape and cooling. The twist straightening device 1 includes a first die 10 for pressing a foot portion 103 of the rail 100 and a second die 20 for pressing a head portion 101 of the rail 100 on one side (the upper side in Fig. 5) of the longitudinal direction of the rail 100 (the direction indicated by the arrow y).

In addition, the rail twist straightening device 1 of the first modified example, like the twist straightening device 1 of the first embodiment, is equipped with a third die 30 that presses the head portion 101 of the rail 100 and a fourth die 40 that presses the foot portion 103 of the rail 100 on the other longitudinal side of the rail 100 (the lower side in Figure 5).
The first mold 10 and the third mold 30 are arranged on one side (left side in Figure 5) of the width direction of the rail 100 (direction indicated by arrow x), and the second mold 20 and the fourth mold 40 are arranged on the other side (right side in Figure 5) of the width direction of the rail 100.
Here, in the twist straightening device 1 according to the first embodiment, the first die 10 and the second die 20 are arranged to face each other in the width direction of the rail 100 at a first position a on one side in the longitudinal direction of the rail 100. Moreover, the third die 30 and the fourth die 40 are arranged to face each other in the width direction of the rail 100 at a second position b on the other side in the longitudinal direction of the rail 100.

In contrast, in the twist straightening device 1 of the first modified example, the first die 10 is positioned slightly toward the second position b from the first position a in the longitudinal direction of the rail 100, and the second die 20 is positioned slightly on the opposite side to the second position b from the first position a in the longitudinal direction of the rail 100, which is different.
Furthermore, the twist straightening device 1 of the first modified example differs in that the third die 30 is positioned slightly opposite the first position a from the second position b in the longitudinal direction of the rail 100, and the fourth die 40 is positioned slightly toward the first position a from the second position b in the longitudinal direction of the rail 100.

In this way, even with the arrangement of the first die 10, the second die 20, the third die 30, and the fourth die 40 as in the twist straightening device 1 of the first modified example, the twist of the rail 100 after it has been hot rolled into the product shape and cooled can be accurately corrected.
In other words, the first die 10 and the second die 20 do not necessarily have to be arranged to face each other in the width direction of the rail 100 at the first position a on one side in the longitudinal direction of the rail 100. Moreover, the third die 30 and the fourth die 40 do not necessarily have to be arranged to face each other in the width direction of the rail 100 at the second position b on the other side in the longitudinal direction of the rail 100. Although it depends on the size and twisting state of the rail 100, the amount of deviation of these facing positions in the longitudinal direction is allowed to be twice the height dimension of the rail 100.
(Second Modification)
Next, a rail twist straightening device according to a second modified example will be described with reference to Fig. 6. Fig. 6 is a plan view of the rail twist straightening device according to the second modified example. In Fig. 6, the same members as those shown in Fig. 1 are given the same reference numerals, and their description may be omitted.

The rail twist straightening device 1 according to the second modified example shown in Fig. 6, like the rail twist straightening device 1 according to the first embodiment shown in Fig. 1, is adapted to straighten twists in a rail 100 shown in Fig. 11 after hot rolling into a product shape and cooling. The twist straightening device 1 includes first dies 10A, 10B for pressing a foot portion 103 of the rail 100 and a second die 20 for pressing a head portion 101 of the rail 100 on one side (the upper side in Fig. 6) of the longitudinal direction of the rail 100 (the direction indicated by the arrow y).
In addition, the rail twist straightening device 1 of the second modified example, like the twist straightening device 1 of the first embodiment, is equipped with a third die 30 for pressing the head portion 101 of the rail 100 and fourth dies 40A, 40B for pressing the foot portion 103 of the rail 100 on the other longitudinal side of the rail 100 (the lower side in Figure 6).

The first molds 10A, 10B and the third mold 30 are arranged on one side (left side in Figure 6) of the width direction of the rail 100 (direction indicated by arrow x), and the second mold 20 and the fourth molds 40A, 40B are arranged on the other side (right side in Figure 6) of the width direction of the rail 100.
Here, in the twist straightening device 1 according to the first embodiment, the first die 10 and the second die 20 are arranged to face each other in the width direction of the rail 100 at a first position a on one side in the longitudinal direction of the rail 100. Moreover, the third die 30 and the fourth die 40 are arranged to face each other in the width direction of the rail 100 at a second position b on the other side in the longitudinal direction of the rail 100.

In contrast to this, in the twist straightening device 1 according to the second modified example, the second die 20 is disposed at a first position a on one side in the longitudinal direction of the rail 100. However, the first dies 10A and 10B are different from the twist straightening device 1 according to the first embodiment in that they are composed of two dies, that is, the first die 10A disposed on the opposite side to the second position b with respect to the first position a in the longitudinal direction of the rail 100, and the first die 10B disposed on the second position b side with respect to the first position a in the longitudinal direction of the rail 100.
Moreover, in the twist straightening device 1 according to the second modification, the third die 30 is disposed at the second position b on the other side in the longitudinal direction of the rail 100. However, the fourth dies 40A, 40B are different from the twist straightening device 1 according to the first embodiment in that they are composed of two dies, that is, the fourth die 40A disposed on the first position a side with respect to the second position b in the longitudinal direction of the rail 100, and the fourth die 40B disposed on the opposite side to the first position a side with respect to the second position b in the longitudinal direction of the rail 100.

In this way, even with the arrangement of the first dies 10A, 10B, the second die 20, the third die 30, and the fourth dies 40A, 40B as in the twist straightening device 1 of the second modified example, the twist of the rail 100 after it has been hot rolled into the product shape and cooled can be accurately corrected.
In other words, the number of the first mold, the second mold, the third mold, and the fourth mold may not be one, but may be two or more.
In Figure 6, symbol 11A denotes a first holder that holds the first mold 10A, 12A denotes a fall prevention plate provided on the first holder 11A, 13A denotes a connecting bolt for connecting the fall prevention plate 12A to the first holder 11A, and 14A denotes a metal spring that connects the fall prevention plate 12A and the first plate 15.

In addition, in Figure 6, symbol 11B is a first holder that holds the first mold 10B, 12B is a fall prevention plate provided on the first holder 11B, 13B is a connecting bolt for connecting the fall prevention plate 12B to the first holder 11B, and 14B is a metal spring that connects the fall prevention plate 12B and the first plate 15.
Furthermore, in Figure 6, symbol 41A is a fourth holder that holds the fourth mold 40A, 42A is a fall prevention plate provided on the fourth holder 41A, 43A is a connecting bolt for connecting the fall prevention plate 42A to the first holder 41A, and 44A is a metal spring that connects the fall prevention plate 42A and the fourth plate 45.

In addition, in Figure 6, symbol 41B is a fourth holder that holds the fourth mold 40B, 42B is a fall prevention plate provided on the fourth holder 41B, 43B is a connecting bolt for connecting the fall prevention plate 42B to the first holder 41B, and 44B is a metal spring that connects the fall prevention plate 42B and the fourth plate 45.
Second Embodiment
Next, a rail twist straightening device according to a second embodiment of the present invention will be described with reference to Figures 7 and 8. Figure 7 is a cross-sectional view similar to the cross-sectional view taken along line A-A' in Figure 1, of a rail twist straightening device according to the second embodiment of the present invention. Figure 8 is a cross-sectional view similar to the cross-sectional view taken along line B-B' in Figure 1, of a rail twist straightening device according to the second embodiment of the present invention. In Figures 7 and 8, the same members as those shown in Figures 2 and 3 are designated by the same reference numerals, and their description may be omitted.

The rail twist straightening device 1 according to the second embodiment shown in Figures 7 and 8 has the same basic configuration as the rail twist straightening device 1 according to the first embodiment shown in Figures 1 to 3. However, the rail twist straightening device 1 according to the second embodiment differs from the twist straightening device 1 according to the first embodiment in that rollers 16, 26, 36, and 46 are provided between the first to fourth holders 11 to 41 and the first to fourth plates 15 to 45, respectively.
7, the first holder 11 is disposed on the inside in the width direction of the first plate 15 and is installed so as to be movable up and down relative to the inner surface of the first plate 15. Furthermore, a plurality of rollers 16 are provided between the first holder 11 and the inner surface of the first plate 15. These rollers 16 are held by a cage (not shown) so as to be able to roll freely and not to come apart. This cage is fixed to the inner surface of the first plate 15.

Even if the first holder 11 is installed so as to be freely movable up and down relative to the inner surface of the first plate 15, depending on the situation, the first holder 11 may not be able to move up and down smoothly relative to the inner surface of the first plate 15. In response to this, by providing a plurality of rollers 16 between the first holder 11 and the inner surface of the first plate 15, it becomes possible for the first holder 11 to move up and down smoothly relative to the inner surface of the first plate 15.
As a result, when the first mold 10 presses the foot 103 of the rail 100, the reaction force causes the first holder 11 to move smoothly up and down relative to the first plate 15, and no load is placed on components such as the fall prevention plate 12 and connecting bolt 13 that prevent the first holder 11 from falling, reliably preventing damage to these components.

Similarly, the second holder 21 is disposed on the inside of the second plate 25 in the width direction and is installed so as to be vertically movable with respect to the inner surface of the second plate 25. Furthermore, a plurality of rollers 26 are provided between the second holder 21 and the inner surface of the second plate 25. These rollers 26 are similarly held by a retainer (not shown) so as to be able to roll freely and not come apart. This retainer is fixed to the inner surface of the second plate 25.
By providing a plurality of rollers 26 between the second holder 21 and the inner surface of the second plate 25, the second holder 21 can move smoothly up and down relative to the inner surface of the second plate 25.

As a result, when the second die 20 presses against the head 101 of the rail 100, the reaction force causes the second holder 21 to move smoothly up and down relative to the second plate 25, and no load is placed on components such as the fall prevention plate 22 and the connecting bolt 23, which prevent the second holder 21 from falling, so that damage to these components can be reliably prevented.
8, the third holder 31 is disposed on the inner side of the third plate 35 in the width direction and is installed so as to be movable up and down relative to the inner surface of the third plate 35. Furthermore, a plurality of rollers 36 are provided between the third holder 31 and the inner surface of the third plate 35. These rollers 36 are similarly held by a cage (not shown) so as to be able to roll freely and not to come apart. This cage is fixed to the inner surface of the third plate 35.

By providing a plurality of rollers 36 between the third holder 31 and the inner surface of the third plate 35, the third holder 31 can move smoothly up and down relative to the inner surface of the third plate 35.
As a result, when the third die 30 presses the head 101 of the rail 100, the reaction force causes the third holder 31 to move smoothly up and down relative to the third plate 35, and no load is placed on components such as the fall prevention plate 32 and the connecting bolt 33, which prevent the third holder 31 from falling, so that damage to these components can be reliably prevented.
Similarly, the fourth holder 41 is disposed on the inner side of the fourth plate 45 in the width direction and is installed so as to be movable up and down relative to the inner surface of the fourth plate 45. Furthermore, a plurality of rollers 46 are provided between the fourth holder 41 and the inner surface of the fourth plate 45. These rollers 46 are held by a retainer (not shown) so as to be able to roll freely and not to come apart. This retainer is fixed to the inner surface of the fourth plate 45.

By providing a plurality of rollers 46 between the fourth holder 41 and the inner surface of the fourth plate 45 , the fourth holder 41 can move smoothly up and down relative to the inner surface of the fourth plate 45 .
As a result, when the fourth die 40 presses against the foot 103 of the rail 100, the reaction force causes the fourth holder 41 to move smoothly up and down relative to the fourth plate 45, and no load is placed on components such as the fall prevention plate 42 and the connecting bolt 43, which prevent the fourth holder 41 from falling, so that damage to these components can be reliably prevented.
Moreover, the rail twist straightening device 1 according to the second embodiment can also accurately straighten the twist of the rail 100.
Third Embodiment
Next, a rail twist straightening device according to a second embodiment of the present invention will be described with reference to Figures 9 and 10. Figure 9 is a cross-sectional view similar to the cross-sectional view taken along line A-A' in Figure 1, of a rail twist straightening device according to the second embodiment of the present invention. Figure 10 is a cross-sectional view similar to the cross-sectional view taken along line B-B' in Figure 1, of a rail twist straightening device according to the second embodiment of the present invention. In Figures 9 and 10, the same members as those shown in Figures 2 and 3 are denoted by the same reference numerals, and their description may be omitted.

The rail twist straightening device 1 according to the second embodiment shown in Figs. 9 and 10 has the same basic configuration as the rail twist straightening device 1 according to the first embodiment shown in Figs. 1 to 3. However, the rail twist straightening device 1 according to the third embodiment differs from the twist straightening device 1 according to the first embodiment in that the fall prevention plates 12 to 42 fixed to the first to fourth holders 11 to 41, respectively, are placed directly on the upper surfaces of the first to fourth plates 15 to 45. In other words, in the twist straightening device 1 according to the third embodiment, the fall prevention plates 12 to 42 of the first to fourth holders 11 to 41, respectively, and the upper surfaces of the first to fourth plates 15 to 45 are not connected by the metal springs 14 to 44 as elastic bodies.

The rail twist straightening device 1 according to the third embodiment can also accurately straighten the twist of the rail 100.
Although the embodiment of the present invention has been described above, the present invention is not limited to this and various modifications and improvements can be made.
For example, when correcting the twist of the rail 100, it is possible to use the twist correction device 1 to correct not only the twist in the longitudinal leading end region and the longitudinal trailing end region of the rail 100, but also to correct the twist in an appropriate region in the longitudinal direction of the rail 100 depending on the degree and location of the twist of the rail 100.

In addition, when straightening the twist of the rail 100, the twist is straightened once each in the longitudinal leading end region and the longitudinal trailing end region of the rail 100, but it may be performed multiple times in each region depending on the degree of twist.
In addition, the rail 100 may be transported by table rollers (not shown) with the longitudinal end of the rail 100 (the lower end in FIG. 1) at the leading edge, and loaded into the twist straightening device 1 from the side where the first die 10 and the second die 20 are arranged (the upper side in FIG. 1).
Furthermore, in the rail straightening device 1 according to the first and second embodiments, examples have been described in which the metal springs 14 to 44 are used as the elastic bodies, but the elastic bodies are not limited to metal springs and may be rubber members.

Furthermore, the holding of each of the first to fourth dies 10 to 40 by each of the first to fourth holders 11 to 41 is not limited to the case where each of the T-shaped first to fourth dies 10 to 40 is fitted into the dovetail grooves of each of the first to fourth holders 11 to 41.
In addition, the first die 10 and the third die 30 provided on the fixed side plate 50 side and the second die 20 and the fourth die 40 provided on the movable side plate 60 side may be interchanged depending on the direction in which the twist of the rail 100 is to be corrected.
In the rail twist straightening device 1 according to the third embodiment, the first to fourth holders 11 to 41 may be fixed to the first to fourth plates 15 to 45, respectively.

The twist straightening was carried out on a rail with a mass of 162 kg per meter and a length of 25 m.
In Examples 1 to 3, the above-mentioned rail twist straightening was carried out using the rail twist straightening device 1 of the third embodiment shown in Figs. 9 and 10, which does not use the metal springs 14 to 44 and the rollers 16 to 46.
In addition, in Examples 4 to 6, the above-mentioned rail twist straightening was carried out using the rail twist straightening device 1 of the first embodiment shown in Figures 1 to 3, which uses metal springs 14 to 44 and does not use rollers 16 to 46.

Furthermore, in Examples 7 and 8, the above-mentioned rail twist straightening was carried out using the rail twist straightening device 1 of the second embodiment shown in Figs.
The results of the twist straightening are shown in Table 1.

In Table 1, when comparing the amount of torsion before straightening and the amount of torsion after straightening, it can be seen that in all of Examples 1 to 8, the amount of torsion after straightening was reduced compared to the amount of torsion before straightening at both the front end and rear end sides of the rail, and the amount of torsion after straightening was within the control value of 5 mm.
Therefore, it was confirmed that the rail twist straightening device 1 according to the first to third embodiments can accurately straighten the rail twist.
It was confirmed that the degree of improvement in the amount of twist was greater when rail twist straightening was performed using the rail twist straightening device 1 of the first embodiment in Examples 4 to 6, which uses the metal springs 14 to 44 and does not use the rollers 16 to 46, than when rail twist straightening was performed using the rail twist straightening device 1 of the third embodiment in Examples 1 to 3, which does not use the metal springs 14 to 44 and the rollers 16 to 46.

It was also confirmed that the degree of improvement in the amount of twist was greater when rail torsion straightening was performed using the rail torsion straightening device 1 of the second embodiment in Examples 7 and 8, which used the metal springs 14 to 44 and the rollers 16 to 46, than when rail torsion straightening was performed using the rail torsion straightening device 1 of the first embodiment in Examples 4 to 6, which used the metal springs 14 to 44 but did not use the rollers 16 to 46.
In addition, in Example 3, although the first to fourth holders 11 to 41 are arranged so as to be freely movable up and down relative to the first to fourth plates 15 to 45, the first to fourth holders 11 to 41 cannot move up and down smoothly relative to the first to fourth plates 15 to 45, and deformation of the fall prevention plates 12 to 42 was confirmed.

LIST OF SYMBOLS 1 Rail twist correction device 10 First die 10A First die 10B First die 11 First holder 11A First holder 11B First holder 12 Fall prevention plate 12A Fall prevention plate 12B Fall prevention plate 13 Connection bolt 13A Connection bolt 13B Connection bolt 14 Metal spring 14A Metal spring 14B Metal spring 15 First plate 16 Roller 20 Second die 20a Die body 20b Protruding portion 21 Second holder 21a First groove portion 21b Second groove portion 22 Fall prevention plate 23 Connection bolt 24 Metal spring 25 Second plate 26 Roller 30 Third die 31 Third holder 32 Fall prevention plate 33 Connection bolt 34 Metal spring 35 Third plate 36 Roller 40 Fourth die 40A Fourth die 40B Fourth die 41 Fourth holder 41A Fourth holder 41B Fourth holder 42 Fall prevention plate 42A Fall prevention plate 42B Fall prevention plate 43 Connecting bolt 43A Connecting bolt 43B Connecting bolt 44 Metal spring 44A Metal spring 44B Metal spring 45 Fourth plate 46 Roller 50 Fixed side plate 60 Movable side plate 70 Pressing down cylinder 100 Rail 101 Head 101a Top surface 101b Head side surface on the left side in the width direction 101c Head side surface on the right side in the width direction 102 Body 103 Foot 103a Bottom surface 103b Tip on the left side in the width direction 103c Tip on the right side in the width direction a 1st position b 2nd position

Claims (8)

A rail twist straightening device for straightening a twist of a rail extending in a longitudinal direction, comprising:
a first die for pressing a foot portion of the rail and a second die for pressing a head portion of the rail, on one side of the rail in a longitudinal direction;
a third die for pressing the head portion of the rail and a fourth die for pressing the foot portion of the rail on the other side in the longitudinal direction of the rail,
The device for straightening twist of a rail, characterized in that the first die and the third die are arranged on one side of the rail in a width direction, and the second die and the fourth die are arranged on the other side of the rail in the width direction. The rail twist correction device according to claim 1, characterized in that the first die, the second die, the third die, and the fourth die are held by a first holder, a second holder, a third holder, and a fourth holder, respectively, and the first holder, the second holder, the third holder, and the fourth holder are installed so as to be movable up and down relative to the first plate, the second plate, the third plate, and the fourth plate, respectively. The rail twist correction device according to claim 2, characterized in that the first holder, the second holder, the third holder, and the fourth holder are provided with a fall prevention plate on the upper surface thereof, which is placed on the first plate, the second plate, the third plate, and the fourth plate, and prevents the first holder, the second holder, the third holder, and the fourth holder from falling. The rail twist correction device according to claim 3, characterized in that the fall prevention plates of the first holder, the second holder, the third holder, and the fourth holder, respectively, and the upper surfaces of the first plate, the second plate, the third plate, and the fourth plate are connected by an elastic body that maintains the vertical position of the first holder, the second holder, the third holder, and the fourth holder, respectively. The rail twist correction device according to claim 4, characterized in that rollers are provided between the first holder, the second holder, the third holder, and the fourth holder, respectively, and the first plate, the second plate, the third plate, and the fourth plate, respectively. The device for straightening twisted rails according to any one of claims 1 to 5, characterized in that the pressing of the first die against the foot of the rail, the pressing of the second die against the head of the rail, the pressing of the third die against the head of the rail, and the pressing of the fourth die against the foot of the rail are achieved when the second die and the fourth die are moved by the pressing cylinder in a direction approaching the first die and the third die, respectively, when straightening the twisted rails, and the release of the pressing of the first die against the foot of the rail, the release of the pressing of the second die against the head of the rail, the release of the pressing of the third die against the head of the rail, and the release of the pressing of the fourth die against the foot of the rail are achieved when the second die and the fourth die are moved by the pressing cylinder in a direction away from the first die and the third die, respectively. A method for straightening a twist of a rail extending in a longitudinal direction, comprising the steps of:
At one side of the rail in the longitudinal direction, a first die arranged on one side of the rail in the width direction presses a foot portion of the rail, and a second die arranged on the other side of the rail in the width direction presses a head portion of the rail,
A method for straightening twist of a rail, comprising the steps of pressing a head portion of the rail with a third die arranged on one side of the rail in the width direction, and pressing a foot portion of the rail with a fourth die arranged on the other side of the rail in the width direction. A method for manufacturing a rail, comprising a twist straightening step for straightening the twist of the rail by the method for straightening the twist of the rail described in claim 7.

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