Rail fastening device for direct coupling to steel bridge and method of assembling the same

Abstract

To provide a rail fastening device for directly connecting a steel bridge and its assembling method capable of easily adjusting the position of a tie plate and improving workability.SOLUTION: A rail fastening device 4 for directly connecting a steel bridge fastens a tie plate 12 supporting a rail to a bridge girder side 3a of the steel bridge 3 by a fastening member 13. The fastening member 13 includes a fastening bolt 14 that is inserted into a through-hole 3a of the bridge girder 3b and a through-hole 12f of the tie plate 12 from below the bridge girder 3a, a fastening nut 15 that is fastened to the fastening bolt 14 so as to sandwich the bridge girder 14a between the fastening nut 15 and a head 3a of the fastening bolt 14, and a fastening nut 18 that is fastened to the fastening bolt 14 so as to sandwich the bridge girder 3a and the tie plate 12 between the fastening nut 18 and the head 14 of the fastening bolt 14. The tie plate 12 is an insulating tie plate that is sandwiched between the rail and the bridge girder side 3a to electrically insulate them.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rail fastening device for direct connection to a steel bridge, which fastens a rail to a bridge girder of a steel bridge via a tie plate, and to an assembly method thereof. [Background technology]

[0002] Traditionally, in railway bridge sections, wooden or synthetic resin bridge sleepers have been fastened to steel bridge girders with rail fastening devices, and the bridge sleepers have been secured to the girders with hook bolts. However, in recent years, instead of this fastening method of securing rails to bridge sleepers, rail fastening devices for direct connection to steel bridges have been adopted, which fasten rails to the steel girders of steel bridges without using sleepers.

[0003] A conventional rail fastening device for direct connection to a steel bridge (improved steel direct rail fastening device (hereinafter referred to as Prior Art 1)) comprises an insulating plate sandwiched between the steel bridge's steel plate upper flange and the rail, insulating clamps that press down on the left and right bottom upper surfaces of the rail, lateral pressure receiving fittings that directly receive lateral pressure from the left and right of the rail, a first fastening member that fastens the insulating clamp to the lateral pressure receiving fitting, and a second fastening member that fastens the lateral pressure receiving fitting to the steel plate upper flange (see, for example, Non-Patent Document 1). In Prior Art 1, the first fastening member presses the insulating clamp against the bottom upper surface of the rail to fasten the insulating clamp to the lateral pressure receiving fitting, and the second fastening member fastens the lateral pressure receiving fitting to the steel plate upper flange.

[0004] A conventional rail fastening device for direct connection to a steel bridge (improved steel straight II rail fastening device (hereinafter referred to as Prior Art 2)) comprises a track pad with ultra-hard rubber (with EB material) that is sandwiched between the steel bridge's upper steel plate flange and the rail, insulating clamps that press down on the bottom upper surfaces of the left and right sides of the rail, lateral pressure receiving fittings that directly receive lateral pressure from the left and right of the rail, a first fastening member that fastens the insulating clamps to the lateral pressure receiving fittings, and a second fastening member that fastens the lateral pressure receiving fittings to the steel plate upper flange (see, for example, Non-Patent Document 2). Prior Art 2, like Prior Art 1, uses the first fastening member to press the insulating clamp against the bottom upper surface of the rail to fasten the insulating clamp to the lateral pressure receiving fitting, and the second fastening member to fasten the lateral pressure receiving fitting to the steel plate upper flange. [Prior art documents] [Patent documents]

[0005] [Non-Patent Document 1] Takaharu Nagato and two others, "Development of an improved steel straight rail fastening device," Journal of the Japan Railway Construction Association, Japan Railway Construction Association, 1988, Vol. 26, No. 7, pp. 505-508

[0006] [Non-patent document 2] Osamu Wakatsuki, "Improved Steel Straight Type II Rail Fastening Device", Facilities Research News, Railway Technical Research Institute, Facilities Research News Editorial Committee, December 1, 2008, No. 220, pp. 1 / 8-2 / 8 Summary of the Invention [Problem to be solved by the invention]

[0007] Tracks are gradually deformed by repeated train passage and natural phenomena, sometimes resulting in track irregularities that change the longitudinal and lateral shapes of the rails on which vehicles travel. This requires work to correct the track irregularities within a specified range. In this case, if the fastening bolts are attached from under the girder of the steel plate upper flange, it is time-consuming for workers to enter under the girder to do the work, and there is also the problem that the fastening bolts may fall off the steel plate upper flange when loosening them. In particular, in the case of box girders, it is difficult for workers to enter inside the box girder to do the work.

[0008] Rail fastening devices for direct connection to steel bridges must ensure electrical insulation between the steel bridge and the rail to prevent track short-circuit accidents. Research and development has been carried out on rail fastening devices for direct connection to steel bridges to date, with an aim to prevent track short-circuit accidents caused by parts falling off by improving the electrical insulation through improvements to the components and reducing the number of components, as well as to improve the efficiency of fastening work by creating a structure that allows for rail fastening and loosening, which allows for adjustment work for alignment deviations. However, track short-circuit accidents have not yet been eliminated.

[0009] An object of the present invention is to provide a rail fastening device for direct connection to a steel bridge, which can improve workability and enable easy position adjustment of the tie plate, and an assembly method thereof. [Means for solving the problem]

[0010] The present invention solves the above problems by the means described below. Although the reference numerals corresponding to the embodiments of the present invention are given in parentheses, the present invention is not limited to these embodiments. The invention of claim 1 is a rail fastening device (4) for direct connection to a steel bridge, as shown in Figures 2, 5 to 7, and 9, which fastens a tie plate (12) supporting a rail (2) to a bridge girder (3a) of a steel bridge (3) with fastening members (13), wherein the fastening members include a fastening bolt (14) inserted from below the bridge girder into a through hole (3b) in the bridge girder and a through hole (12f) in the tie plate, a first fastening nut (15) fastened to the fastening bolt so as to sandwich the bridge girder between the fastening bolt and the head (14a) of the fastening bolt, and a second fastening nut (18) fastened to the fastening bolt so as to sandwich the bridge girder and the tie plate between the fastening bolt and the head (14a).

[0011] The invention of claim 2 is a rail fastening device for direct connection to a steel bridge according to claim 1, characterized in that the tie plate is an insulating tie plate that is sandwiched between the rail and the bridge girder to electrically insulate them.

[0012] The invention of claim 3 is a rail fastening device for direct connection to a steel bridge as described in claim 1, characterized in that the through hole of the tie plate is an elongated hole that allows the position of the tie plate to be adjusted in a direction intersecting the longitudinal direction of the rail, as shown in Figures 2, 3, 5 to 7 and 9.

[0013] The invention of claim 4 is a rail fastening device for direct connection to a steel bridge according to claim 1, characterized in that the tie plate has ceramics sprayed onto the metal surface.

[0014] The invention of claim 5 is the rail fastening device for direct connection to a steel bridge according to claim 1, characterized in that the tie plate is made of ceramics.

[0015] The invention of claim 6 is the rail fastening device for direct connection to a steel bridge according to claim 1, characterized in that, as shown in FIG. 7, the tie plate is adjusted in position on the bridge girder by loosening the second fastening nut.

[0016] The invention of claim 7 is a method for assembling a rail fastening device for direct connection to a steel bridge, which fastens a tie plate (12) supporting a rail (2) to a bridge girder (3a) of a steel bridge (3) with a fastening member (13), as shown in Figures 2, 5, 6 and 9, and includes a fastening bolt insertion step (#110) of inserting a fastening bolt (14) of the fastening member into a through hole (3b) of the bridge girder from below the bridge girder, and a step of fastening the first fastening nut (15) of the fastening member to the fastening bolt so as to sandwich the bridge girder between the head (14a) of the fastening bolt and the first fastening nut (15) of the fastening member. This is a method (#100) for assembling a rail fastening device for directly connecting a steel bridge, which includes a first fastening nut tightening step (#120), a tie plate installation step (#130) for installing the tie plate on the bridge girder so that the fastening bolt with the first fastening nut tightened thereto is inserted into the through hole (12f) of the tie plate, and a second fastening nut tightening step (#140) for tightening the second fastening nut to the fastening bolt so that the bridge girder and the tie plate are sandwiched between the head of the fastening bolt and a second fastening nut (18) of the fastening member. [Effects of the Invention]

[0017] According to the present invention, workability can be improved and the position of the tie plate can be easily adjusted. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a plan view of a rail fastening device according to a first embodiment of the present invention. [Figure 2] 1 is a partially cutaway front view of a rail fastening device according to a first embodiment of the present invention. [Figure 3] FIG. 1 is a plan view of a tie plate of a rail fastening device according to a first embodiment of the present invention. [Figure 4] 1A to 1C are assembly views of fastening bolts and fastening nuts of fastening members that fasten a tie plate of a rail fastening device according to a first embodiment of the present invention to a bridge girder, where (A) is a plan view, (B) is a front view, and (C) is a bottom view. [Figure 5] 1A and 1B are front views showing a state in which the fastening bolts of the fastening member are attached to the bridge girder, and FIG. 1B is a front view showing a state in which the tie plate of the rail fastening device according to the first embodiment of the present invention has been fastened to the bridge girder by the fastening bolts of the fastening member. [Figure 6] 1A and 1B are schematic diagrams for explaining the assembly method of the rail fastening device for direct connection to a steel bridge according to the first embodiment of the present invention, in which (A) is a schematic diagram of the fastening bolt insertion process, (B) is a schematic diagram of the fastening nut tightening process, (C) is a schematic diagram of the tie plate installation process, and (D) is a schematic diagram of the fastening nut tightening process. [Figure 7] 1A and 1B are schematic diagrams for explaining a position adjustment method for a rail fastening device for direct connection to a steel bridge according to a first embodiment of the present invention, in which (A) is a schematic diagram showing the state before position adjustment, (B) is a schematic diagram showing the state in which the fastening nut has been removed and the tie plate is being adjusted in position, and (C) is a schematic diagram showing the state after position adjustment. [Figure 8] FIG. 4 is a plan view of a rail fastening device according to a second embodiment of the present invention. [Figure 9] FIG. 6 is a partially cutaway front view of a rail fastening device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] (First embodiment) A first embodiment of the present invention will be described in detail below with reference to the drawings. 1 and 2 is a member that comes into rolling contact with a rail 2. The wheel 1 has a tread surface 1a that comes into contact with the head surface 2d of the rail head 2a and receives frictional resistance, and a flange surface 1b that is formed continuously on the outer periphery of the wheel 1 to prevent it from coming off the track.

[0020] The rail 2 is a member that supports and guides the wheels 1 of a railway vehicle, allowing the railway vehicle to travel. The rail 2 comprises a rail head 2a, a rail bottom (flange portion) 2b, and a rail web (web portion) 2c. The rail head 2a is the portion that comes into contact with the wheels 1. The rail head 2a comprises a head top surface (top upper surface) 2d that directly supports the wheels 1, and head side surfaces 2e that form the left and right side surfaces of the rail head 2a and are continuous with the head top surface 2d. The rail bottom 2b is the portion that is supported by the tie plate 12. The rail bottom 2b is installed and attached to the tie plate 12 by the rail fastening device 4. The rail bottom 2b comprises an upper bottom surface 2f that is pressed by the fastening springs 7 of the rail fastening device 4, a lower bottom surface 2g that comes into contact with the track pad 5, and bottom side surfaces 2h that form the left and right side surfaces of the rail bottom 2b. The rail web portion 2c is the portion that connects the rail head 2a and the rail bottom 2b. The rail web 2c transmits the wheel load and lateral pressure acting on the rail head 2a to the rail bottom 2b. The rail 2 shown in Figures 1 and 2 is, for example, a 50 kgN rail used mainly on conventional lines, or a 60 kgN rail used on the Shinkansen (registered trademark) and major conventional lines.

[0021] The steel bridge 3 shown in Figure 2 is a bridge that secures space below the tracks on which railway vehicles travel and supports the weight of the trains. Steel bridges 3 are constructed to cross water areas such as rivers, valleys, and lakes, or transportation routes such as roads and railways. The steel bridge 3 shown in Figure 2 is an iron girder bridge, etc., which uses steel as its main material. The steel bridge 3 comprises a bridge girder 3a, which forms the main part of the steel bridge 3 and over which railway vehicles pass, and a through hole 3b that penetrates the bridge girder 3a.

[0022] The rail fastening device 4 shown in Figures 1 and 2 fastens a tie plate 12 to a bridge girder 3a with fastening members 13. The rail fastening device 4 fastens the rail 2 to the tie plate 12 with fastening members 8, and fastens the tie plate 12 to the bridge girder 3a with fastening members 13. The rail fastening device 4 shown in Figures 1 and 2 is a steel bridge direct-connection type rail fastening device that directly fastens the rail 2 to the bridge girder 3a via the tie plate 12 without using bridge sleepers used in steel bridges. The rail fastening device 4 includes a track pad 5 shown in Figure 2, an adjustable packing 6, a fastening spring 7 shown in Figures 1 and 2, a fastening member 8, a tie plate 12 shown in Figures 1 to 3, and a fastening member 13 shown in Figures 1 to 5. The rail fastening device 4 shown in Figures 1 and 2 can easily replace an existing steel straight type II rail fastening device, for example, by utilizing the through-hole 3b without processing the steel bridge 3.

[0023] The track pad 5 shown in Figure 2 is an elastic body inserted between the rail 2 and the tie plate 12. The track pad 5 is a plate-like member made of vulcanized rubber or urethane and sandwiched between the rail bottom 2b and the tie plate 12 to absorb the impact load generated when a train passes and to ensure resistance to the longitudinal movement of the rail 2. The track pad 5 is provided with a steel plate 5a on the surface on the side that comes into contact with the rail bottom 2b. The track pad 5 functions to provide electrical insulation between the rail 2 and the tie plate 12.

[0024] The adjustment packing 6 is a member that is inserted between the rail 2 and the tie plate 12 to adjust the vertical position of the rail 2. The adjustment packing 6 is a variable pad that, for example, is a sheet-like bag that is inserted between the track pad 5 and the tie plate 12, and synthetic resin is pressed into the bag and hardened to adjust the height of the rail 2 as desired.

[0025] The fastening spring 7 shown in FIGS. 1 and 2 is a spring that presses against the rail 2. The fastening spring 7 generates a restoring force (elastic force) when the fastening spring 7 is compressed from its neutral position by a fastening member 8. The fastening spring 7 exerts a restoring force on the bottom upper surface 2f of the rail 2 as a pressing force (fastening force) that presses against the bottom upper surface 2f. As shown in FIG. 2, the fastening spring 7 is a leaf spring (main spring) formed by bending a plate-shaped spring steel into a substantially S-shape. It functions as both a presser foot (spring clip) and a compression spring that receives a compressive load. The fastening spring 7 includes an upper spring portion 7a shown in FIGS. 1 and 2, a lower spring portion 7b shown in FIG. 2, a bent portion 7c shown in FIGS. 1 and 2, and notches 7d and 7e shown in FIG. 2. The upper spring portion 7a shown in FIGS. 1 and 2 is the portion that constitutes the upper leaf spring of the fastening spring 7. As shown in FIG. 2, the upper spring portion 7a presses down on the lower spring portion 7b from above. The lower spring portion 7b is the portion that constitutes the lower leaf spring of the fastening spring 7. The lower spring portion 7b presses down on the bottom upper surface 2f of the rail 2 by the elastic force of the leaf spring. The bent portion 7c is a portion formed by bending spring steel into a roughly U-shape. The notches 7d and 7e shown in FIGS. 1 and 2 are portions that penetrate the upper spring portion 7a and the lower spring portion 7b. As shown in FIG. 2, the notches 7d and 7e are formed with a predetermined length from the tip ends of the upper spring portion 7a and the lower spring portion 7b toward the bent portion 7c, and function as a through portion for passing the fastening bolt 14 of the fastening member 13.

[0026] The fastening member 8 shown in Figures 1 and 2 is a member that fastens the rail 2 to the tie plate 12. The fastening member 8 generates a restoring force (elastic force) in the fastening spring 7 by compressing the fastening spring 7, and the restoring force acts from the fastening spring 7 to the bottom upper surface 2f as a pressing force (fastening force) that presses down on the bottom upper surface 2f of the rail 2. The fastening member 8 includes a fastening bolt 9, a fastening nut 10, and a washer 11. The fastening member 8 shown in Figures 1 and 2 can be manufactured at low cost by using fastening members that include, for example, a fastening spring, fastening bolt, fastening nut, track pad, and adjustment packing that constitute an existing direct-coupled type 8 rail fastening device used on slab tracks for conventional lines or Shinkansen (registered trademark).

[0027] The fastening bolt 9 is a component that is detachably attached to the tie plate 12. The fastening bolt 9 has a male threaded portion 9a shown in FIGS. 1 and 2, a latch portion 9b shown in FIG. 2, and a rotation prevention portion 9c shown in FIGS. 2 and 3. The male threaded portion 9a shown in FIGS. 1 and 2 is the portion that meshes with the fastening nut 10. As shown in FIG. 2, the male threaded portion 9a is formed on the upper part of the fastening bolt 9 and is inserted into the notches 7d and 7e of the fastening spring 7. The latch portion 9b is a portion that fits with the latch portion 12d on the tie plate 12 side. The latch portion 9b is formed in a T-shape on the lower part of the fastening bolt 9 so that it can be caught on the latch portion 12d to prevent the fastening bolt 9 from slipping out of the tie plate 12. The rotation prevention portion 9c shown in FIGS. 2 and 3 is a portion that fits with the rotation prevention portion 12e on the tie plate 12 side. As shown in Fig. 3, anti-rotation portion 9c has a rectangular cross-sectional shape, and by fitting with anti-rotation portion 12e, it prevents the fastening bolt 9 from rotating around the center line relative to the tie plate 12. The fastening nut 10 shown in Figs. 1 and 2 is a member that tightens the fastening spring 7. The fastening nut 10 has a female thread that meshes with the male thread 9a of the fastening bolt 9, and is fastened to the fastening bolt 9 in a detachable manner. The washer 11 is a member that is sandwiched between the fastening spring 7 and the fastening nut 10.

[0028] The tie plate 12 shown in Figures 1 to 3 is a component installed between the rail 2 and the bridge girder 3a. As shown in Figure 2, the tie plate 12 supports the rail 2 and is inserted and sandwiched between the rail 2 and the bridge girder 3a. As shown in Figure 3, the tie plate 12 is a fastening component with a rectangular planar shape and is detachably attached to the bridge girder 3a. The tie plate 12, together with the track pad 5 and the fastening spring 7, constitutes a dual-elastic fastening device. As shown in Figure 2, the tie plate 12 shown in Figures 1 to 3 is installed with the rail 2 tilted toward the inside of the gauge (inside the left and right rails 2) (tilted installation), thereby reducing the force acting from the wheel 1 to the rail 2. As shown in Figure 7, the position of the tie plate 12 on the bridge girder 3a can be adjusted by loosening the fastening nuts 18.

[0029] The tie plate 12 shown in FIGS. 1 to 3 is an insulating tie plate that is sandwiched between the rail 2 and the bridge girder 3a to electrically insulate them. The tie plate 12 may be a ceramic-sprayed tie plate, in which ceramic is sprayed onto a metal surface, or may be made of ceramic. If the tie plate 12 is a ceramic-sprayed tie plate, the ceramic is sprayed onto the top, bottom, end faces, side faces, and the inner circumferential surfaces of the through holes 12f (the entire surface of the tie plate 12). Ceramic-sprayed tie plates are manufactured by flame spraying, plasma spraying, or high-velocity flame (gas) spraying ceramic powder, such as alumina (aluminum oxide), titanium oxide, alumina and titanium oxide, chromium oxide, zirconia and magnesium oxide, or alumina and zirconia, onto a metal base material such as iron or stainless steel at a temperature of 250°C or less. When the tie plate 12 is made of ceramic, the ceramic powder is formed into a predetermined shape and then heat-treated and sintered to produce a sintered ceramic tie plate. The tie plate 12 includes a tie plate seat surface 12a shown in Figures 2 and 3, a shoulder portion 12b shown in Figures 1 to 3, a spring receiving portion 12c, a latch portion 12d shown in Figure 3, an anti-rotation portion 12e, and a through hole 12f shown in Figures 2 and 3.

[0030] The tie plate seating surface 12a shown in Figures 2 and 3 is the portion where the rail 2 is installed. The tie plate seating surface 12a is formed as a flat, inclined surface, and the track pad 5 and adjustment packing 6 are sandwiched between the bottom lower surface 2g of the rail 2 and this tie plate seating surface 12a. The shoulder portion 12b shown in Figures 1 to 3 is a portion that restricts lateral movement of the rail 2. As shown in Figure 3, the shoulder portion 12b is formed continuously along the width direction of the tie plate 12 and protrudes from the top surface of the tie plate 12 as shown in Figure 2. The shoulder portion 12b is a wall portion formed opposite to each other so as to sandwich the bottom side surface 2h of the rail 2, and positions the rail bottom portion 2b on the tie plate 12. The spring seating portion 12c shown in Figures 1 to 3 is a portion that positions the fastening spring 7. The spring receiving portion 12c is a recess formed in the upper surface of the tie plate 12 over a predetermined length from one edge of the tie plate 12 to the other edge thereof so as to sandwich the bent portion 7c of the fastening spring 7 therebetween.

[0031] The latch portion 12d shown in FIG. 3 is a portion that latches the latch portion 9b on the fastening bolt 9 side. The latch portion 12d functions as an attachment portion for attaching the fastening bolt 9 and also as a retaining portion that prevents the fastening bolt 9 from slipping out upward from the tie plate 12. As shown in FIG. 3, the latch portion 12d is formed in a T-shape to match the shape of the latch portion 9b, so that the upper surface of the shoulder portion 12b is cut out in a concave shape. The anti-rotation portion 12e shown in FIG. 3 is a portion that prevents the fastening bolt 9 from rotating around the central axis. As shown in FIG. 3, the anti-rotation portion 12e is formed into parallel flat surfaces so that its width is slightly wider than the anti-rotation portion 9c on the fastening bolt 9 side, and it detachably fits with the anti-rotation portion 9c on the fastening bolt 9 side.

[0032] The through holes 12f shown in FIGS. 2 and 3 are portions into which the fastening bolts 14 of the fastening members 13 are inserted. As shown in FIG. 3, the through holes 12f are elongated holes that allow the position of the tie plate 12 to be adjusted in a direction intersecting the longitudinal direction of the rail 2. As shown in FIG. 2, the through holes 12f are formed at positions corresponding to the through holes 3b on the bridge girder 3a side, extending in the longitudinal direction of the tie plate 12 and having a predetermined length. As shown in FIG. 3, the width of the through holes 12f is formed so as to be larger than the diagonal distance, which is the distance between the opposing corners of the fastening nuts 15 of the fastening members 13 (the maximum outer diameter of the fastening nuts 15). For example, by forming the through holes 12f in the same positions as the through holes of a tie plate used in an existing steel straight type II rail fastening device, the through holes 12f are formed in the same positions as the through holes 3b of the bridge girder 3a. This allows for easy replacement with existing steel straight type II rail fastening devices without processing the steel bridge 3.

[0033] The fastening member 13 shown in FIGS. 1 to 5 is a member that fastens the tie plate 12 to the bridge girder 3a. The fastening member 13 includes a fastening bolt 14 shown in FIGS. 1, 2, 4, and 5, a fastening nut 15 shown in FIGS. 2, 4, and 5, washers 16 and 17 shown in FIGS. 2 and 5, a fastening nut 18 shown in FIGS. 1, 2, 4, and 5, a cover plate 19 shown in FIGS. 1, 2, and 5, an insulating collar 20, a plain washer 21, a spring washer 22, and a plain washer 23. As shown in FIG. 5, the fastening member 13 fastens the fastening bolt 14 to the bridge girder 3a to prevent the fastening bolt 14 from falling off the bridge girder 3a. As shown in FIG. 7, the fastening member 13 fastens the tie plate 12 to the bridge girder 3a so that the position of the tie plate 12 can be adjusted in the longitudinal direction while the fastening bolt 14 remains attached to the bridge girder 3a. As shown in FIG. 4, the fastening member 13 has two fastening nuts 15, 18 attached to the fastening bolt 14 at a distance from each other, and as shown in FIGS. 2 and 5, it fixes the fastening bolt 14 to the bridge girder 3a and also fixes the tie plate 12 to the bridge girder 3a.

[0034] The fastening bolt 14 shown in FIGS. 1, 2, 4, and 5 is a component that is detachably attached to the bridge girder 3a. As shown in FIGS. 2 and 5, the fastening bolt 14 is inserted into the through-hole 3b of the bridge girder 3a and the through-hole 12f of the tie plate 12 from below the bridge girder 3a. As shown in FIG. 5(A), the fastening bolt 14 is inserted into the through-hole 3b from below the bridge girder 3a and protrudes upward from the through-hole 12f of the tie plate 12. The fastening bolt 14 has a head 14a shown in FIGS. 2, 4, and 5 and a male thread 14b shown in FIGS. 1, 2, 4, and 5. The head 14a shown in FIGS. 2, 4, and 5 is a portion that is rotated using a tool when attaching or detaching the fastening bolt 14. The male thread 14b shown in FIGS. 1, 2, 4, and 5 is a portion that engages with a fastening nut 15. As shown in Figures 2, 4 and 5, the male thread portion 14b is formed at a predetermined length from the tip of the fastening bolt 14, and is inserted into the through hole 3b of the bridge girder 3a and the through hole 12f of the tie plate 12 as shown in Figures 2 and 5.

[0035] The fastening nut 15 shown in Figures 2, 4, and 5 is a member that tightens the bridge girder 3a between itself and the fastening bolt 14. As shown in Figures 2 and 5, the fastening nut 15 is fastened to the fastening bolt 14 so as to sandwich the bridge girder 3a between itself and the head 14a of the fastening bolt 14. The fastening nut 15 has an internal thread that meshes with the external thread 14b of the fastening bolt 14, and is detachably fastened to the fastening bolt 14. The fastening nut 15 secures the fastening bolt 14 to the bridge girder 3a by sandwiching the bridge girder 3a between the bearing surface of the head 14a of the fastening bolt 14 and the bearing surface of the fastening nut 15, thereby preventing the fastening bolt 14 from slipping out of the through-hole 3b of the bridge girder 3a. The washer 16 shown in Figures 2 and 5 is a member that is sandwiched between the bearing surface of the head 14a of the fastening bolt 14 and the underside of the bridge girder 3a. The washer 17 is a member that is sandwiched between the bearing surface of the fastening nut 15 and the upper surface of the bridge girder 3a.

[0036] The fastening nut 18 shown in Figures 1, 2, 4, and 5 is a component that tightens the tie plate 12 between the fastening bolt 14 and the fastening nut 18. As shown in Figures 2 and 5, the fastening nut 18 is fastened to the fastening bolt 14 so as to sandwich the bridge girder 3a and the tie plate 12 between the fastening nut 18 and the head 14a of the fastening bolt 14. The fastening nut 18 has an internal thread that meshes with the external thread 14b of the fastening bolt 14, and as shown in Figures 2, 3, and 5, the fastening nut 18 is detachably fastened to the fastening bolt 14 above the position at which the fastening nut 15 is fastened to the fastening bolt 14. As shown in Figures 2 and 5, the fastening nut 18 secures the tie plate 12 to the bridge girder 3a by sandwiching the bridge girder 3a and the tie plate 12 between the bearing surface of the head 14a of the fastening bolt 14 and the bearing surface of the fastening nut 15.

[0037] 1, 2, and 5 is a member that prevents foreign matter from entering the through-hole 12f of the tie plate 12. As shown in FIGS. 2 and 5, the cover plate 19 is sandwiched between the upper surface of the tie plate 12 and the lower surface of the insulating collar 20, thereby preventing rainwater or dust from entering the through-hole 12f of the tie plate 12.

[0038] 1, 2, and 5 is a member that provides electrical insulation between the fastening member 13 and the tie plate 12. The insulating collar 20 is an insulating member made of synthetic resin. As shown in FIG. 5, the insulating collar 20 includes a flange portion 20a that is sandwiched between the upper surface of the cover plate 19 and the lower surface of the flat washer 21, and a tubular portion 20b that is inserted into the through hole 12f of the tie plate 12 and through which the fastening bolt 14 and fastening nut 15 pass.

[0039] 1, 2, and 5 is a member sandwiched between the upper surface of the flange portion 20a of the insulating collar 20 and the lower surface of the spring washer 22. The spring washer 22 is a member sandwiched between the upper surface of the plain washer 21 and the lower surface of the plain washer 23. The plain washer 23 is a member sandwiched between the seat surface of the fastening nut 18 and the upper surface of the spring washer 22.

[0040] Next, a method for assembling the rail fastening device for direct connection to a steel bridge according to the first embodiment of the present invention will be described. 6 is a method for assembling a rail fastening device 4 that fastens a tie plate 12 that supports a rail 2 to a bridge girder 3a. The rail fastening method #100 for directly connecting a steel bridge includes a fastening bolt insertion process #110, a fastening nut tightening process #120, a tie plate installation process #130, and a fastening nut tightening process #130.

[0041] The fastening bolt insertion process #110 shown in FIG. 6(A) is a process of inserting a fastening bolt 14 into the through hole 3b of the bridge girder 3a from below the bridge girder 3a. For example, when updating an existing steel straight type II rail fastening device with a rail fastening device 4, the through hole 3b is formed in the bridge girder 3a to match the position of the through hole in the tie plate of the steel straight type II rail fastening device. Therefore, the existing through hole 3b of the bridge girder 3a is used as is, and the fastening bolt 14 is inserted into the through hole 3b. When a rail fastening device 4 is newly installed in the bridge girder 3a of a newly constructed steel bridge 3, the fastening bolt 14 is inserted into the through hole 3b of the bridge girder 3a that is formed to match the position of the through hole 12f of the tie plate 12 of the rail fastening device 4. With a washer 16 attached to the fastening bolt 14, the tip of the male thread portion 14b side of the fastening bolt 14 is inserted into the through hole 3b from below to above the bridge girder 3a.

[0042] The fastening nut tightening process #120 shown in Figure 6(B) is a process of tightening the fastening nut 15 to the fastening bolt 14 so that the bridge girder 3a is sandwiched between the head 14a of the fastening bolt 14 and the fastening nut 15. As shown in Figure 6(A), a washer 17 is attached to the male threaded portion 14b of the fastening bolt 14 protruding from the top surface of the bridge girder 3a, and then the female threaded portion of the fastening nut 15 is engaged with the male threaded portion 14b of the fastening bolt 14 as shown in Figure 6(B), thereby tightening the fastening nut 15 to the fastening bolt 14. As a result, the fastening bolt 14 is fixed and integrated with the bridge girder 3a, and the fastening bolt 14 is prevented from slipping out downward through the through hole 3b of the bridge girder 3a and falling.

[0043] Tie plate installation process #130 shown in Figure 6(C) is a process of installing the tie plate 12 on the bridge girder 3a so that the fastening bolts 14 with fastening nuts 15 fastened thereto are inserted into the through holes 12f of the tie plate 12. With the fastening nuts 15 fastened to the fastening bolts 14, the tie plate 12 is installed on the bridge girder 3a so that the fastening bolts 14 and the fastening nuts 15 are inserted into the through holes 12f of the tie plate 12.

[0044] The fastening nut tightening step #130 shown in Figure 6(D) is a step of tightening the fastening nut 18 onto the fastening bolt 14 so that the bridge girder 3a and tie plate 12 are sandwiched between the head 14a of the fastening bolt 14 and the fastening nut 18. After the cover plate 19, insulating collar 20, plain washer 21, spring washer 22, and plain washer 23 are attached to the fastening bolt 14 in this order, the female thread portion of the fastening nut 18 is engaged with the male thread portion 14b of the fastening bolt 14, and the fastening nut 18 is tightened onto the fastening bolt 14. As a result, the tie plate 12 is fixed to the bridge girder 3a, and the rail 2 is fixed to the bridge girder 3a via the tie plate 12.

[0045] Next, a position adjusting method for a rail fastening device for direct connection to a steel bridge according to the first embodiment of the present invention will be described. 7 is a method for adjusting the position of a rail fastening device 4 that fastens a tie plate 12 that supports a rail 2 to a bridge girder 3a. The position adjustment method #200 includes a fastening nut loosening process #210, a position adjustment process #220, and a fastening nut tightening process #220.

[0046] The fastening nut loosening process #210 shown in Figure 7(A) is a process of loosening the fastening nut 18 from the fastening bolt 14. As shown in Figure 7(A), by loosening the fastening nut 18 fastened to the fastening bolt 14, the force with which the fastening bolt 14 and the fastening nut 18 press down on the tie plate 12 is reduced without completely removing the fastening nut 18 from the fastening bolt 14. At this time, because the fastening nut 15 remains fastened to the fastening bolt 14, the fastening bolt 14 is prevented from slipping out of the through-hole 3b of the bridge girder 3a and falling from the bridge girder 3a.

[0047] Position adjustment step #220 shown in Figure 7(B) is a step of adjusting the position of the tie plate 12 on the bridge girder 3a by loosening the fastening nut 18. As shown in Figure 7(B), the position of the tie plate 12 is adjusted in a direction perpendicular to the rail 2 while the fastening nut 18, cover plate 19, insulating collar 20, flat washer 21, spring washer 22, and flat washer 23 remain attached to the fastening bolt 14. For example, to correct the lateral displacement of the rail 2 in the longitudinal direction, the tie plate 12 is slid on the bridge girder 3a to adjust the position of the tie plate 12 by an adjustment amount Δ (the adjustment amount (movement amount) of the rail 2), and the position of the rail 2 is adjusted integrally with the tie plate 12 by the adjustment amount Δ.

[0048] The fastening nut tightening step #230 shown in Figure 7(C) is a step of tightening the fastening nuts 18 onto the fastening bolts 14. As shown in Figure 7(C), after the position of the tie plate 12 has been adjusted, the fastening nuts 18 are tightened onto the fastening bolts 14, and the fastening nuts 18 are tightened onto the fastening bolts 14, thereby fixing the tie plate 12 to the bridge girder a.

[0049] The rail fastening device for direct connection to a steel bridge according to the first embodiment of the present invention has the following effects. (1) In this first embodiment, fastening members 13 fasten the tie plate 12 to the bridge girder 3a, and fastening bolts 14 of the fastening members 13 are inserted from below the bridge girder 3a into the through holes 3b in the bridge girder 3a and the through holes 12f in the tie plate 12. Furthermore, in this first embodiment, fastening nuts 15 are fastened to the fastening bolts 14 so that the bridge girder 3a is sandwiched between the heads 14a of the fastening bolts 14 and the fastening nuts 15, and fastening nuts 18 are fastened to the fastening bolts 14 so that the bridge girder 3a and the tie plate 12 are sandwiched between the heads 14a of the fastening bolts 14 and the fastening nuts 15. Therefore, the bridge girder 3a is sandwiched between the heads 14a of the fastening bolts 14 and the fastening nuts 15, preventing the fastening bolts 14 from falling off the bridge girder 3a. As a result, for example, when attaching or detaching the tie plate 12 or adjusting the position of the tie plate 12, the work can be easily performed by simply loosening the fastening nuts 18. Furthermore, the tie plate 12 can be easily fastened to the bridge girder 3a using the fastening member 13, which has a simple structure consisting of one fastening bolt 14 and two fastening nuts 15, 18. As a result, the fastening member 13 can be constructed with a small number of parts, allowing for efficient fastening work. Furthermore, when correcting alignment deviation, workers do not need to enter under the bridge girder 3a. The position of the tie plate 12 can be easily adjusted using the fastening member 13, which has a simple structure, simply by loosening and fastening the fastening nut 18. Furthermore, while prior arts 1 and 2 use a structure in which left and right lateral pressure bearing brackets located on the inside and outside of the rail gauge are fastened to the bridge girder using four fastening bolts and fastening nuts, this embodiment uses a structure in which the tie plate 12 is fastened to the bridge girder 3a using two fastening bolts 14 and fastening nuts 18. This reduces the number of fastening bolts and fastening nuts, allowing for quick and easy installation of the tie plate 12.

[0050] (2) In this first embodiment, the tie plate 12 is an insulating tie plate that is sandwiched between the rail 2 and the bridge girder 3a to electrically insulate them. Therefore, by fastening the rail 2 to the tie plate 12 and fastening the tie plate 12 to the bridge girder 3a, the rail 2 and the bridge girder 3a can be electrically insulated from each other. As a result, by installing the electrically insulated tie plate 12 between the rail 2 and the bridge girder 3a, the rail 2 and the bridge girder 3a can be separated by the insulating material, thereby achieving high insulation. For example, compared to using electrically insulating left and right lateral pressure bearing brackets arranged on the inside and outside of the rail gauge, the use of a single electrically insulating tie plate 12 allows for electrical insulation between the rail 2 and the bridge girder 3a with a simple structure.

[0051] (3) In the first embodiment, the through-hole 12f of the tie plate 12 is an elongated hole that allows the position of the tie plate 12 to be adjusted in a direction intersecting the longitudinal direction of the rail 2. Therefore, when correcting a lateral displacement of the rail 2, for example, the position of the tie plate 12 can be easily adjusted by simply loosening the fastening nut 18.

[0052] (4) In the first embodiment, the tie plate 12 is manufactured by spraying ceramic onto the surface of a metal. This provides excellent wear resistance to the surface of the tie plate 12. Furthermore, for example, ceramic spraying can be applied to a steel tie plate 12 to provide the tie plate 12 with insulating properties.

[0053] (5) In the first embodiment, the tie plate 12 is made of ceramic. This makes it possible to impart wear resistance to the tie plate 12 and to provide insulation throughout the entire tie plate 12. For example, an insulating tie plate can be easily manufactured by molding ceramic powder into the shape of the tie plate 12 and then firing it.

[0054] (6) In this first embodiment, the position of the tie plate 12 on the bridge girder 3a is adjusted by loosening the fastening nuts 18. Therefore, when correcting alignment deviation, the tie plate 12 can be easily moved simply by loosening and retightening the fastening nuts 18. For example, the tie plate 12 alone can be easily moved while the fastening nuts 18, cover plate 19, insulating collar 20, flat washer 21, spring washer 22, and flat washer 23 remain attached to the fastening bolts 14. Furthermore, there is no need for workers to enter under the girders of the steel bridge 3 to loosen and retighten the fastening nuts 18 each time alignment deviation correction work is performed. This eliminates the need for workers to enter under the girders of the steel bridge 3 to loosen and retighten the fastening nuts 18, allowing alignment deviation correction to be performed in a short time, thereby improving the efficiency of alignment deviation correction work.

[0055] (Second embodiment) In the following, the same parts as those shown in FIGS. 1 to 7 are denoted by the same reference numerals and detailed description thereof will be omitted. The rail fastening device 4 shown in Figures 8 and 9 is a rail fastening device directly connected to a steel bridge, having substantially the same structure as the rail fastening device 4 shown in Figures 1 to 7. In the rail fastening device 4 shown in Figures 8 and 9, the position of the through hole 12f of the tie plate 12 shown in Figure 9 differs from the position of the through hole 12f of the tie plate 12 shown in Figures 2, 3, and 5; the through hole 12f of the tie plate 12 shown in Figures 8 and 9 is located closer to the center line of the tie plate seat surface 12a. For example, by forming the through hole 12f shown in Figures 8 and 9 in the same position as the through hole of the tie plate of an existing improved steel straight rail fastening device, it will be formed in the same position as the through hole 3b of the bridge girder 3a, and can be easily replaced with an existing improved steel straight rail fastening device without processing the steel bridge 3. This second embodiment has the same effects as the first embodiment.

[0056] (Other embodiments) The present invention is not limited to the above-described embodiment, and various modifications and alterations are possible as described below, and these are also within the scope of the present invention. In this embodiment, a rail fastening device for direct connection to a steel bridge has been described as an example, in which the rail 2 is pressed down by the fastening springs 7 of the fastening members 8. However, the present invention can also be applied to a rail fastening device for direct connection to a steel bridge in which a rail press fitting or an insulating press tool is pressed down to the rail 2 by a leaf spring or a coil spring. Also, in this embodiment, an example has been described in which, when correcting alignment displacement of the rail 2, the fastening nuts 18 are loosened from the fastening bolts 14, and the tie plate 12 is moved with the cover plate 19 and other components still attached to the fastening bolts 14. However, the present invention is not limited to such a position adjustment method. For example, the present invention can also be applied to a case in which alignment displacement is corrected by moving the tie plate 12 with the fastening nuts 18 and the cover plate 19 and other components removed from the fastening bolts 14. [Explanation of symbols]

[0057] 1 wheel 2 Rails 3 steel bridge 3a Bridge girder 4 Rail fastening device 5 Railroad Pad 6 Adjustment packing 7 Fastening spring 8 Fastening members 9 Fastening bolts 10 Fastening nut 12 tie plates 12f through hole 13 Fastening members 14 Fastening bolt 14a head 14b Male thread 15 Fastening nut (first fastening nut) 16,17 Washer 18 Fastening nut (second fastening nut) 19 Cover plate 20 Insulation Color 21 Flat washer 22 Spring washer 23 Flat washer Δ adjustment amount

Claims

1. A rail fastening device for direct connection to a steel bridge that fastens a tie plate supporting a rail to a bridge girder of a steel bridge using fastening members, The fastening member is a fastening bolt inserted into the through hole of the bridge girder and the through hole of the tie plate from below the bridge girder; a first fastening nut fastened to the fastening bolt so as to sandwich the bridge girder between the fastening nut and the head of the fastening bolt; a second fastening nut fastened to the fastening bolt so as to sandwich the bridge girder and the tie plate between the fastening bolt and the head of the fastening bolt; A rail fastening device for direct connection to steel bridges.

2. The rail fastening device for direct connection to a steel bridge according to claim 1, the tie plate is an insulating tie plate that is sandwiched between the rail and the bridge girder to electrically insulate them; A rail fastening device for direct connection to steel bridges.

3. The rail fastening device for direct connection to a steel bridge according to claim 1, the through-hole of the tie plate is an elongated hole that allows the position of the tie plate to be adjusted in a direction intersecting the longitudinal direction of the rail; A rail fastening device for direct connection to steel bridges.

4. The rail fastening device for direct connection to a steel bridge according to claim 1, the tie plate has a metal surface on which ceramics is sprayed; A rail fastening device for direct connection to steel bridges.

5. The rail fastening device for direct connection to a steel bridge according to claim 1, the tie plate is made of ceramic; A rail fastening device for direct connection to steel bridges.

6. The rail fastening device for direct connection to a steel bridge according to claim 1, the tie plate is adjusted in position on the bridge girder by loosening the second fastening nut; A rail fastening device for direct connection to steel bridges.

7. A method for assembling a rail fastening device for direct connection to a steel bridge, which fastens a tie plate supporting a rail to a bridge girder of a steel bridge using fastening members, comprising: a fastening bolt insertion process of inserting a fastening bolt of the fastening member into the through-hole of the bridge girder from below the bridge girder; a first fastening nut tightening step of tightening the first fastening nut to the fastening bolt so as to sandwich the bridge girder between the head of the fastening bolt and the first fastening nut of the fastening member; a tie plate installation process of installing the tie plate on the bridge girder so that the fastening bolt to which the first fastening nut has been fastened is inserted into the through hole of the tie plate; a second fastening nut tightening step of tightening the second fastening nut to the fastening bolt so as to sandwich the bridge girder and the tie plate between the head of the fastening bolt and the second fastening nut of the fastening member; A method for assembling a rail fastening device for direct connection to a steel bridge, comprising:

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