Rail fastening structure

Abstract

A rail fastening structure is provided that includes a fastening spring made of a non-metallic material that has excellent electrical insulation and corrosion resistance. [Solution] A rail fastening structure for fastening a rail to a concrete sleeper includes a resin block placed on the concrete sleeper so as to abut against the upper surface and side surfaces of the rail bottom of the rail, a resin spring placed on the upper surface of the resin block, and a fastening bolt for fixing the resin block and the resin spring to the concrete sleeper, wherein the resin spring has an elastic force imparting structure that imparts an elastic force to the upper surface of the rail bottom via the resin block.

Description

[Technical Field]

[0001] The present invention relates to a rail fastening structure for fastening a rail to a concrete sleeper. [Background technology]

[0002] BACKGROUND ART When fastening rails such as railway rails to concrete sleepers, a rail fastening structure is used in which the rails are held by metal members such as leaf springs.

[0003] Conventionally, various structures have been known as such rail fastening structures. For example, as described in Patent Document 1, a rail fastening structure is known that includes a metal leaf spring that is in direct contact with the top surface and side surfaces of the bottom of the rail. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 3-89701 Summary of the Invention [Problem to be solved by the invention]

[0005] The leaf springs used in conventional rail fastening structures hold the bottom of the rail with a specified spring force, thereby suppressing excessive displacement and vibration in the vertical and horizontal directions that occurs in the rail, which is elastically supported by track pads, when a train passes, as well as a decrease in the axial force of the fastening bolts due to creep of the track pads that elastically support the rail.

[0006] Furthermore, the rail fastening structure has the function of insulating the current of the track circuit for detecting trains and the return current for driving trains.

[0007] However, because components used in conventional rail fastening structures are generally made of iron-based materials, corrosion occurs in areas such as tunnel leaks and in areas near the sea. Because spring steel is used for fastening springs, even if fastening bolts, washers, and other components are changed to corrosion-resistant alloys such as stainless steel, there is a risk of galvanic corrosion occurring between the fastening springs and the springs. If this corrosion progresses, there is a risk of the leaf springs breaking or falling off, causing train transportation disruptions. In contrast, when resin leaf springs are used, the leaf springs are not only not corroded but also do not undergo galvanic corrosion. Therefore, by using stainless steel bolts in combination, the corrosion resistance of the entire fastening structure can be improved.

[0008] Therefore, the present invention has been made in consideration of the above problems, and aims to provide a rail fastening structure equipped with a fastening spring made of a non-metallic material that has excellent electrical insulation and corrosion resistance. [Means for solving the problem]

[0009] The present invention has been made to achieve the above object and has the following features.

[0010] The rail fastening structure of the present invention is a rail fastening structure for fastening a rail to a concrete sleeper, and is characterized in that it comprises a resin block placed on the concrete sleeper so as to abut against the upper surface and side surfaces of the rail bottom of the rail, a resin spring placed on the upper surface of the resin block, and a fastening bolt for fixing the resin block and the resin spring to the concrete sleeper, and the resin spring has an elastic force imparting structure that imparts an elastic force to the upper surface of the rail bottom via the resin block.

[0011] In the rail fastening structure according to the present invention, it is preferable that the elastic force imparting structure is such that the resin spring is curved so that the cross-sectional shape in the extending direction of the rail is upwardly convex.

[0012] In the rail fastening structure according to the present invention, it is preferable that the elastic force imparting structure is such that the resin spring is curved so that the cross-sectional shape in a direction perpendicular to the extending direction of the rail is upwardly convex.

[0013] In the rail fastening structure according to the present invention, it is preferable that the elastic force imparting structure includes a groove portion formed in the resin spring in a direction perpendicular to the extending direction of the rail.

[0014] In the rail fastening structure according to the present invention, it is preferable that a pair of the groove portions be formed on both sides of a bolt hole through which the fastening bolt is inserted.

[0015] In the rail fastening structure according to the present invention, it is preferable that the groove portion is formed from the tip portion in contact with the resin block to a base end side beyond the position where the bolt hole is formed.

[0016] In the rail fastening structure according to the present invention, it is preferable that a plate member extending in the extending direction of the rail is interposed between the resin spring and the bolt head of the fastening bolt.

[0017] The above summary of the invention does not list all of the features necessary for the present invention, and subcombinations of these features may also constitute inventions. [Effects of the Invention]

[0018] According to the present invention, the fastening spring used in the rail fastening structure can be made of resin, thereby realizing a rail fastening structure with excellent electrical insulation and corrosion resistance. Furthermore, the resin fastening spring according to the second embodiment of the present invention can have a uniform cross-sectional shape in the direction perpendicular to the extending direction of the rail, which enables molding by extrusion molding or the like, thereby realizing a rail fastening structure with a fastening spring that is easy to mass-produce. [Brief explanation of the drawings]

[0019] [Figure 1]1 shows a state in which a rail is held by a rail fastening structure according to a first embodiment of the present invention, in which the right half from the center line is a cross-sectional view and the left half is an external view. [Figure 2] FIG. 2 is an enlarged view of part A in FIG. [Figure 3] 1 is a perspective view showing a resin spring according to a first embodiment of the present invention. [Figure 4] 1 is a front view showing a resin spring according to a first embodiment of the present invention. [Figure 5] FIG. 10 shows a state in which a rail is held by a rail fastening structure according to a second embodiment of the present invention, with the right half from the center line being a cross-sectional view and the left half being an external view. [Figure 6] FIG. 6 is an enlarged view of part B in FIG. 5. [Figure 7] FIG. 10 is a perspective view showing a resin spring according to a second embodiment of the present invention. [Figure 8] FIG. 10 is a perspective view showing a resin spring and a plate member according to a second embodiment of the present invention. [Figure 9] 3 is a graph showing the load applied to the rail by the rail fastening structure according to the first embodiment of the present invention. [Figure 10] 6 is a graph showing the load applied to a rail by a rail fastening structure according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0021] [First embodiment] FIG. 1 shows a state in which a rail 2 is held by a rail fastening structure 1A according to a first embodiment of the present invention, with the right half from the center line being a cross-sectional view and the left half being an external view, FIG. 2 is an enlarged view of part A in FIG. 1, FIG. 3 is a perspective view showing a resin spring 20 according to the first embodiment of the present invention, and FIG. 4 is a front view showing a resin spring 20 according to the first embodiment of the present invention. In this specification, the left-right direction is defined as the direction shown in FIG. 1, and is a direction perpendicular to the extension direction of the rail 2. Furthermore, unless otherwise specified, the following description of each component will be given assuming the position of the component in the state in which the rail 2 is held as shown in FIG. 1.

[0022] As shown in FIG. 1, a rail fastening structure 1A according to the first embodiment fastens a rail 2 to a support body 3.

[0023] The rail 2 supports and guides the wheels of a railway vehicle (not shown) to allow the railway vehicle to travel. The rail 2 comprises a rail head 2a, a rail web 2b, and a rail bottom 2c. The rail head 2a comes into contact with the wheels of the railway vehicle and receives wheel load and lateral force. The rail web 2b connects the rail head 2a and the rail bottom 2c and transmits the wheel load and lateral force acting on the rail head 2a to the rail bottom 2c. The rail bottom 2c is a flange-shaped portion extending to both the left and right sides. It is elastically supported on the bearing 3 via track pads 5 and held in place by the rail fastening structure 1A. The rail bottom 2c also comprises a bottom upper surface 2d that is pressed against a resin block 10 (described later), bottom side surfaces 2e that form the left and right sides of the rail bottom 2c, and a bottom lower surface 2f that forms the underside of the rail 2. The rail 2 shown in FIG. 1 is one of a pair of left and right rails; the other rail is not shown.

[0024] The bearing body 3 is a cross sleeper laid so as to extend in a direction perpendicular to the extension direction of the rails 2, and supports the left and right rails 2 while maintaining a constant gap between them. A plurality of bearing bodies 3 are arranged at predetermined intervals in the extension direction of the rails 2, and distribute the train load transmitted from the rails 2 to the trackbed (not shown). As an example, the bearing body 3 of this embodiment may be a prestressed concrete sleeper that is subjected to a compressive force in the lateral direction by high-tensile steel. The bearing body 3 is equipped with a receiving plug 4 that supports a resin block 10 (described later). The bearing body 3 also has a female thread (not shown) that screws into a fastening bolt 6 (described later). The female thread may be formed by an embedded plug made of synthetic resin such as plastic.

[0025] The socket plugs 4 are plate-shaped components made of synthetic resin such as plastic, and are disposed so as to be embedded in the surface of the support body 3 on both the left and right sides of the rail 2. The socket plugs 4 have through holes 4a through which the bolt shanks 6a of the fastening bolts 6 pass, at positions corresponding to the female threads of the support body 3. In addition, a recess 4b is formed on the top surface of the socket plugs 4 at a position farther from the rail 2 than the through holes 4a.

[0026] The recess 4b is a depression formed in an arc shape in a cross section perpendicular to the extension direction of the rail 2. The recess 4b is formed so as to extend in the extension direction of the rail 2.

[0027] The rail fastening structure 1A according to the first embodiment includes a track pad 5, a fastening bolt 6, a resin block 10, and a resin spring 20.

[0028] The track pads 5 are plate-shaped components made of an elastic material such as rubber, and are placed between the rail 2 and the bearing body 3. The track pads 5 absorb the impact load generated when a railway vehicle passes, and transmit resistance to the bearing body 3 against the progression of the rail 2 in the extension direction. The track pads 5 also protect the surface of the bearing body 3, and electrically insulate the bearing body 3 from the bottom underside 2f of the rail bottom 2c.

[0029] The fastening bolt 6 is a hexagonal bolt having a bolt shank 6a and a bolt head 6b.

[0030] The resin blocks 10 are components made of synthetic resin such as plastic, and are arranged on both the left and right sides of the rail 2 to maintain the mounting position (gauge) of the rail 2. As shown in Figures 1 and 2, the resin blocks 10 include a locking portion 11, a bolt hole 12, a protrusion 13, and an engagement groove 14.

[0031] The locking portion 11 is located at the end closest to the rail 2, and is formed in a stepped shape that corresponds to the shapes of the bottom upper surface 2d and bottom side surface 2e of the rail bottom portion 2c. The locking portion 11 abuts against the bottom upper surface 2d of the rail bottom portion 2c, and functions to receive vertical loads from the rail 2. The locking portion 11 also abuts against the bottom side surface 2e of the rail bottom portion 2c, and functions to receive left-right loads from the rail 2.

[0032] The bolt hole 12 is a through-hole formed at approximately the center of the resin block 10 and sized to allow the bolt shank 6a of the fastening bolt 6 to pass through.

[0033] The protrusion 13 is formed on the underside of the resin block 10 at a position farther from the rail 2 in the left-right direction than the bolt hole 12. The protrusion 13 protrudes downward at a position corresponding to the recess 4b of the receiving plug 4 and is formed with an arc-shaped cross section that can engage with the recess 4b. The protrusion 13 determines the mounting position of the resin block 10 by engaging with the recess 4b. The protrusion 13 also prevents the resin block 10 from rotating around the fastening bolt 6.

[0034] The engagement groove 14 is formed on the upper surface of the resin block 10 at a position farther from the rail 2 in the left-right direction than the bolt hole 12. The engagement groove 14 is a groove formed to correspond to the shape of the base end portion 22 of the resin spring 20 (described later), and is formed to extend in the extension direction of the rail 2. As shown in FIG. 2 as an example, the engagement groove 14 is formed in a substantially triangular shape in a cross section perpendicular to the extension direction of the rail 2.

[0035] The resin spring 20 is a fastening spring that elastically presses the rail 2 via the resin block 10. The resin spring 20 is a plate-like member formed in a substantially rectangular shape, and may be made of, for example, CFRP (Carbon Fiber Reinforced Plastics), which is a resin reinforced with carbon fiber. As shown in FIG. 3 , the resin spring 20 has a center portion 21, a base end portion 22, and a tip end portion 23.

[0036] The central portion 21 is located approximately in the center of the resin spring 20, and has a bolt hole 21a through which the bolt shank 6a of the fastening bolt 6 is inserted. The bolt hole 21a is formed to have a diameter smaller than the width across flats of the hexagonal bolt head 6b of the fastening bolt 6. As shown in FIG. 4, the central portion 21 is formed so that its cross-sectional shape in the extension direction of the rail 2 in the attached state is curved upward and convex along the direction of the arrow indicated by the thick line.

[0037] 2 and 3, the base end 22 is located at the end farther from the rail 2 when the resin spring 20 is attached. The base end 22 includes an inclined portion 22a extending diagonally downward from the central portion 21, and an engagement piece 22b extending diagonally upward from the lower end of the inclined portion 22a on the opposite side to the central portion 21. The engagement piece 22b engages with the engagement groove 14 of the resin block 10 when the resin spring 20 is attached.

[0038] The tip portion 23 is formed so as to extend from the central portion 21 in a direction approaching the rail 2 when the resin spring 20 is in an attached state. Furthermore, as shown in FIG. 4 , the tip portion 23 is formed so that its cross-sectional shape in the extension direction of the rail 2 in the attached state is curved and convex upward, along the direction of the arrow indicated by the thick line. Therefore, both ends of the tip portion 23 in the extension direction of the rail 2 are formed at positions lower in the height direction than the intermediate portion of the tip portion 23 in the extension direction of the rail 2. In this embodiment, both ends of the tip portion 23 in the extension direction of the rail 2 are referred to as contact portions 23a, and approximately the center of the tip portion 23 in the extension direction of the rail 2 is referred to as intermediate portion 23b. The contact portion 23a abuts against the upper surface of the resin block 10 when the resin spring 20 is in an attached state.

[0039] In this manner, in the attached state of the resin spring 20, the engaging piece 22b of the base end portion 22 abuts against the engaging groove 14 of the resin block 10, and the contact portion 23a of the tip portion 23 abuts against the upper surface of the resin block 10. Furthermore, gaps are formed in the vertical direction between the central portion 21 and the resin block 10, and between the intermediate portion 23b of the tip portion 23 and the resin block 10.

[0040] According to the rail fastening structure 1A having such a configuration, the resin block 10 determines the left-right position of the rail 2, and by tightening the fastening bolt 6, the resin spring 20 presses the rail bottom 2c against the support body 3 on which the track pad 5 is laid via the resin block 10. At this time, the resin spring 20 bends vertically due to the tightening of the fastening bolt 6, and elastically holds the rail 2. As a result, even if the rail 2 laid on the track pad 5, which is an elastic body, moves downward due to the weight of a passing train, the resin spring 20 always presses the rail bottom 2c via the resin block 10, and can maintain a state in which the rail 2 is held.

[0041] In addition, the thickness of the tip portion 23 of the resin spring 20 may be changed so that it is thinner than the thickness of the central portion 21, as shown in Figure 3, in order to adjust the force that presses down on the rail 2 when the fastening bolt 6 is tightened.

[0042] [Second embodiment] Above, it has been explained that the rail fastening structure 1A according to the first embodiment is characterized by including a resin spring 20, and that the resin spring 20 is curved so that the cross-sectional shape in the extension direction of the rail 2 is convex upward. Next, a rail fastening structure 1B according to the second embodiment will be explained. The rail fastening structure 1B according to the second embodiment includes a resin spring 30 having a different shape from that of the first embodiment. Note that components that are the same as or similar to those in the first embodiment described above are given the same reference numerals, and detailed explanations will be omitted.

[0043] Figure 5 shows the state in which a rail 2 is held by a rail fastening structure 1B according to a second embodiment of the present invention, with the right half from the center line being a cross-sectional view and the left half being an external view, Figure 6 is an enlarged view of part B in Figure 5, Figure 7 is an oblique view showing a resin spring 30 according to the second embodiment of the present invention, and Figure 8 is an oblique view showing a resin spring 30 and a plate member 40 according to the second embodiment of the present invention.

[0044] 5 and 6, a rail fastening structure 1B according to the second embodiment fastens a rail 2 to a support body 3. The rail fastening structure 1B includes a track pad 5, a fastening bolt 6, a resin block 10, and a resin spring 30. The rail fastening structure 1B may also include a plate member 40 to increase the fastening load of the rail 2 by the resin spring 30 and to alleviate stress concentration in the groove portion 33 of the resin spring 30.

[0045] The resin spring 30 is a fastening spring that elastically presses the rail 2 via the resin block 10. The resin spring 30 is a plate-like member formed in a substantially rectangular shape, and may be made of, for example, CFRP, which is a resin reinforced with carbon fiber. As shown in FIG. 7 , the resin spring 30 includes a center portion 31, a base end portion 32, a groove portion 33, and arm portions 34.

[0046] The central portion 31 is located approximately in the center of the resin spring 30 and has a bolt hole 31a through which the bolt shank 6a of the fastening bolt 6 is inserted. The bolt hole 31a is formed to have a diameter smaller than the width across flats of the bolt head 6b of the fastening bolt 6, which is hexagonal. Furthermore, the central portion 31 is formed so as to be approximately parallel to the upper surface of the resin block 10 in the attached state, as shown in FIG.

[0047] The base end 32 is located at the end farthest from the rail 2 when the resin spring 30 is attached. The base end 32 includes an inclined portion 32a that extends from the central portion 31 in a gently curved downward diagonal direction, and an engagement piece 32b that extends from the lower end of the inclined portion 32a in a curved upward diagonal direction opposite the central portion 31. The engagement piece 32b has an arc-shaped cross section that corresponds to the engagement groove 14 of the resin block 10, and engages with the engagement groove 14 when the resin spring 30 is attached. Note that in this embodiment, the engagement groove 14 and the engagement piece 32b have been described as having arc-shaped cross sections as shown in FIG. 6 . However, the shapes of the engagement groove 14 and the engagement piece 32b are not limited to this. As in the first embodiment, the engagement groove 14 may have a substantially triangular cross section, and the engagement piece 32b may have a bent shape that corresponds to the engagement groove 14.

[0048] The groove portions 33 are grooves formed so as to penetrate the resin spring 30 in the plate thickness direction, and are formed adjacent to the central portion 31 on both sides in the extension direction of the rail 2. The groove portions 33 are formed so as to extend linearly in a direction perpendicular to the extension direction of the rail 2 from the end portion closer to the rail 2 to the base end portion 32 side beyond the bolt hole 31a. In addition, it is preferable that the end portion of the groove portion 33 on the base end portion 32 side, which corresponds to the root of the groove, be formed in an arc shape to avoid stress concentration.

[0049] The arm portion 34 is located outside the groove portion 33 in the extension direction of the rail 2. The arm portion 34 includes a base portion 34a located on the same plane as the central portion 31, and a tip portion 34b extending diagonally downward from the end of the base portion 34a on the opposite side to the base end portion 32. As shown in FIG. 5, the tip portion 34b abuts against the upper surface of the resin block 10 when the resin spring 20 is attached.

[0050] In this manner, in the attached state of the resin spring 30, the engaging piece 32b of the base end 32 abuts against the engaging groove 14 of the resin block 10, and the tip end 34b of the arm portion 34 abuts against the upper surface of the resin block 10. Furthermore, gaps are formed in the vertical direction between the center portion 31 and the resin block 10, and between the base portion 34a of the arm portion 34 and the resin block 10.

[0051] 7, the resin spring 30 is formed so that its cross-sectional shape in a direction perpendicular to the extension direction of the rail 2 is curved and convex upward. That is, the resin spring 30 is formed so that it is curved and convex upward along the direction of the thick arrow shown in FIG. 7. The cross-sectional shape of the resin spring 30 in a direction perpendicular to the extension direction of the rail 2 is uniform. Therefore, the resin spring 30 can be molded by extrusion molding or the like, and has a shape that is more suitable for mass production than the resin spring 20 according to the first embodiment.

[0052] As shown in Fig. 8, the plate member 40 is a plate-like member formed in a substantially rectangular shape and made of synthetic resin such as plastic. In addition, when attached, the plate member 40 covers the groove portion 33 of the resin spring 30 and abuts against the central portion 31 and the base portion 34a of the arm portion 34. A bolt hole 41, through which the bolt shank 6a of the fastening bolt 6 is inserted, is formed in approximately the center of the plate member 40. The bolt hole 41 is formed with a diameter smaller than the width across flats of the bolt head 6b of the fastening bolt 6, which is formed in a hexagonal shape.

[0053] In the rail fastening structure 1B having this configuration, the resin block 10 determines the lateral position of the rail 2. When the fastening bolt 6 is tightened, the plate member 40 presses the resin spring 30, which, via the resin block 10, presses the rail bottom 2c against the support body 3 on which the track pad 5 is placed. At this time, the resin spring 30 bends vertically as the fastening bolt 6 is tightened, elastically holding the rail 2. Furthermore, by disposing the plate member 40 between the resin spring 30 and the bolt head 6b, excessive bending of the arm 34 is suppressed, preventing damage caused by stress concentration at the base of the groove 33 and increasing elastic force. As a result, even if the rail 2, which is laid on the elastic track pad 5, moves downward due to the weight of a passing train, the resin spring 30 always presses the rail bottom 2c via the resin block 10, maintaining the rail 2 in place.

[0054] [Checking the load on the rail] Next, the load applied to the rail by the rail fastening structure according to each embodiment will be explained using graphs. Fig. 9 is a graph showing the load applied to the rail 2 by the rail fastening structure 1A according to the first embodiment, and Fig. 10 is a graph showing the load applied to the rail 2 by the rail fastening structure 1B according to the second embodiment.

[0055] The load applied to the rail 2 by the rail fastening structures 1A and 1B was measured with the rail bottoms 2c on both the left and right sides of the rail 2 fastened by the rail fastening structures 1A and 1B. The horizontal axis of the graphs shown in Figs. 9 and 10 represents the displacement of the rail 2 in the vertical direction, and the vertical axis represents the applied load received by the rail 2. The applied load was measured using a load cell connected to the rail 2.

[0056] 9 and 10, a value of 0 mm on the horizontal axis indicates a state in which the fastening bolts 6 of the rail fastening structures 1A and 1B are tightened with a specified torque and the rail 2 is in its initial position in the up-down direction. Furthermore, a positive value for the displacement on the horizontal axis of the graph indicates a state in which the rail 2 has moved upward from its initial position, and a negative value for the displacement on the horizontal axis of the graph indicates a state in which the rail 2 has moved downward from its initial position.

[0057] The upward movement of the rail 2 is assumed to be caused by the rail tilting and twisting (hereinafter referred to as "small deflection") caused by the lateral pressure of the wheels when a train passes, causing the rail bottom 2c to rise. It can be confirmed that the resin springs 20, 30 continue to function as springs even when the stress calculated by analysis is reached. The downward movement of the rail 2 is assumed to be caused by the rail 2 compressing the track pad 5 due to the wheel load when a train passes. It can be confirmed that the resin springs 20, 30 continue to function as springs even when the sinking amount estimated from the train weight and the elasticity of the track pad 5 is reached. A hysteresis characteristic is confirmed between the load when the rail 2 rises and the load when it falls. This characteristic is mainly caused by the internal friction resistance of the resin block 10 and the like, and the shift in the relative position between the resin springs 20, 30 and surrounding parts when the rail 2 moves up and down.

[0058] In this way, according to the rail fastening structures 1A, 1B of the present invention, even when the rail 2 bounces slightly due to the passage of a train or when the rail 2 sinks, the resin springs 20, 30 can maintain a state in which they elastically hold the rail 2 without impairing their function as springs.

[0059] In the above-described embodiments, the resin springs 20, 30 are described as being made of CFRP, which is a resin reinforced with carbon fiber, but the material of the resin springs 20, 30 is not limited to this, and various conventionally known non-metallic materials may be applied, or a combination of multiple materials may be used. It is clear from the claims that such modified or improved embodiments are also included within the technical scope of the present invention. [Explanation of symbols]

[0060] DESCRIPTION OF SYMBOLS 1A, 1B Rail fastening device, 2 Rail, 2a Rail head, 2b Rail web, 2c Rail bottom, 2d Bottom upper surface, 2e Bottom side surface, 2f Bottom lower surface, 3 Support body, 4 Receptacle, 4a Through hole, 4b Recess, 5 Track pad, 6 Fastening bolt, 6a Bolt shank, 6b Bolt head, 10 Resin block, 11 Locking portion, 12 Bolt hole, 13 Convex portion, 14 Engagement groove, 20 Resin spring, 21 Center portion, 21a Bolt hole, 22 Base end portion, 22a Inclined portion, 22b Engagement piece, 23 Tip portion, 23a Contact portion, 30 Resin spring, 31 Center portion, 31a Bolt hole, 32 Base end portion, 32a Inclined portion, 32b engaging piece, 33 groove portion, 34 arm portion, 34a base portion, 34b tip portion, 40 plate member, 41 bolt hole.

Claims

1. A rail fastening structure for fastening a rail to a concrete sleeper, a resin block placed on the concrete sleeper so as to abut against the upper surface and side surfaces of the rail bottom of the rail; a resin spring disposed on an upper surface of the resin block; a fastening bolt for fixing the resin block and the resin spring to the concrete sleeper, The rail fastening structure is characterized in that the resin spring has an elastic force imparting structure that imparts elastic force to the upper surface of the rail bottom via the resin block.

2. The rail fastening structure according to claim 1, The elastic force imparting structure is a rail fastening structure characterized in that the resin spring is curved so that the cross-sectional shape in the extension direction of the rail is convex upward.

3. The rail fastening structure according to claim 1, The elastic force imparting structure is a rail fastening structure characterized in that the resin spring is curved so that the cross-sectional shape in a direction perpendicular to the extension direction of the rail is convex upward.

4. The rail fastening structure according to claim 1, The rail fastening structure is characterized in that the elastic force imparting structure has a groove portion formed in the resin spring in a direction perpendicular to the extension direction of the rail.

5. The rail fastening structure according to claim 4, A rail fastening structure characterized in that a pair of the groove portions are formed on both sides of a bolt hole through which the fastening bolt is inserted.

6. The rail fastening structure according to claim 5, The groove portion is formed from the tip portion that contacts the resin block to the base end side beyond the position where the bolt hole is formed.

7. The rail fastening structure according to claim 4, A rail fastening structure characterized in that a plate member extending in the extension direction of the rail is interposed between the resin spring and the bolt head of the fastening bolt.

Images