Railway sleeper and method for manufacturing railway sleeper

Abstract

To provide a railway sleeper capable of improving wear resistance of the sleeper while ensuring good lateral resistance of ballast.SOLUTION: A railway sleeper placed on ballast has a sleeper body 110 and a wear-resistant portion 120 containing an elastomer. A plurality of wear-resistant portions 120 are present at least on a lower surface 110a of the sleeper body 110. A total area of the wear-resistant portions 120 present on a lower surface is greater than 70% and less than 95% of an area of the lower surface.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a railway sleeper and a method for manufacturing a railway sleeper. [Background technology]

[0002] One type of railway track is a ballasted track, in which sleepers are placed on ballast and rail members are laid on top of the sleepers. Ballast is often made of hard, angular crushed stone, and contact with the ballast causes wear on the sleepers. This wear is particularly noticeable on the underside of the sleepers. In order to suppress wear of the sleepers, Patent Document 1 proposes a method of covering the sleepers with a protective layer made of an abrasion-resistant material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-165703 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if a soft protective layer is provided between the sleepers and the ballast as in Patent Document 1, there is a possibility that the ballast will dig into the sleepers. Also, if a hard material is used as the protective layer, the sleepers may easily slip on the ballast, which may reduce the lateral resistance of the ballast. When the lateral resistance of the ballast decreases, lateral stability decreases. An object of the present invention is to provide a railway sleeper that can improve the wear resistance of the sleeper while ensuring good ballast lateral resistance. [Means for solving the problem]

[0005] [1] A railway sleeper placed on ballast, comprising a sleeper body and a wear-resistant portion containing an elastomer, wherein a plurality of the wear-resistant portions are present at least on the underside of the sleeper body, spaced apart in the longitudinal direction of the sleeper body, and the total area of ​​the wear-resistant portions present on the underside is greater than 70% and less than 95% of the area of ​​the underside. [2] A railway sleeper as described in [1], wherein on the surface where multiple wear-resistant portions exist, the distance between the wear-resistant portions in the longitudinal direction of the sleeper body is 10 mm or more and 50 mm or less. [3] A railway sleeper as described in [1], wherein on a surface where a plurality of the wear-resistant portions exist, the wear-resistant portions are spaced apart in both the longitudinal direction of the sleeper body and the width direction perpendicular to the longitudinal direction, and the distance between the wear-resistant portions in the longitudinal direction and the distance between the wear-resistant portions in the width direction are both 10 mm or more and 50 mm or less. [4] The railway sleeper according to any one of [1] to [3], wherein the sleeper body is made of a urethane foam reinforced with long glass fibers. [5] The railway sleeper according to any one of [1] to [4], wherein the Shore A hardness of the elastomer is 60 or more and 95 or less. [6] The railway sleeper according to any one of [1] to [5], wherein the thickness of the wear-resistant portion is 1 mm or more and 20 mm or less. [7] The railway sleeper according to any one of [1] to [6], wherein the wear-resistant portion is present on one or more side surfaces of the sleeper body. [8] The railway sleeper according to any one of [1] to [7], wherein the elastomer is a urethane elastomer. [9] A method for manufacturing a railway sleeper according to any one of [1] to [8] above, comprising a coating step of applying a curable elastomer composition to an area of ​​the sleeper body where the wear-resistant portion is to be provided to form a coating film, and a curing step of curing the coating film.

[10] A method for manufacturing railway sleepers as described in [9], wherein the curable elastomer composition is a two-component curable elastomer composition having a base agent and a curing agent, and in the application process, a mixed liquid of the base agent and the curing agent is applied. [Effects of the Invention]

[0006] According to the present invention, a railway sleeper can be obtained that can improve the wear resistance of the sleeper while ensuring good ballast lateral resistance. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a plan view of the railway sleeper of the present embodiment as viewed from the underside. [Figure 2] FIG. 2 is a cross-sectional view taken along the line PP in FIG. [Figure 3] 1A to 1C are schematic diagrams showing an example of a coating device, in which (a) is a front view, (b) is a plan view, and (c) is a side view. [Figure 4] FIG. 1 is a schematic diagram showing an example of a sleeper body manufacturing system. [Figure 5] FIG. 5 is a cross-sectional view showing an example of the molding passage in FIG. 4. [Figure 6] FIG. 10 is a plan view of a railway sleeper according to another embodiment, as viewed from the underside. [Figure 7] FIG. 7 is a cross-sectional view taken along line QQ in FIG. [Figure 8] FIG. 10 is a plan view of a railway sleeper according to another embodiment, as viewed from the underside. [Figure 9] FIG. 10 is a plan view of a railway sleeper according to another embodiment, as viewed from the underside. [Figure 10] FIG. 10 is a plan view of a railway sleeper according to another embodiment, as viewed from the underside. DETAILED DESCRIPTION OF THE INVENTION

[0008] In this specification and claims, the use of "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits. The drawings are schematic diagrams for easily explaining the configuration, and the dimensional ratios of each component may differ from the actual ones.

[0009] <Railway sleepers> The railway sleeper of the present invention (hereinafter also simply referred to as "sleeper") has a sleeper body and a wear-resistant portion. Hereinafter, the railway sleeper of the present invention will be described with reference to one embodiment.

[0010] Fig. 1 is a plan view of a railway sleeper 100 of this embodiment seen from the underside, and Fig. 2 is a cross-sectional view taken along line PP in Fig. 1. The sleeper 100 has a quadrangular prism-shaped sleeper body 110 and a plurality of wear-resistant portions 120 present on the underside 110a of the sleeper body 110. Hereinafter, the longitudinal direction of the sleeper body 110 will be referred to as the X direction, the horizontal direction (width direction) perpendicular to the X direction when the sleeper 100 is placed on a horizontal surface will be referred to as the Y direction, and the direction perpendicular to the X and Y directions will be referred to as the Z direction. Of the outer surfaces of the sleeper body 110, the surfaces perpendicular to the Z direction are referred to as the bottom surface 110a and top surface 110d, the surfaces perpendicular to the X direction are referred to as the side surface 110b, and the surfaces perpendicular to the Y direction are referred to as the side surface 110c. The bottom surface 110a of the sleeper body 110 is the surface that faces downward when the sleeper 100 is placed on ballast. In this embodiment, the wear-resistant portion 120 is present only on the bottom surface 110a of the outer surfaces of the sleeper body 110.

[0011] <Sleeper body> The sleeper body 110 is preferably a synthetic sleeper made of fiber reinforced resin containing reinforcing fibers and cured resin. The reinforcing fibers are preferably bundles of long fibers (fiber bundles), and are preferably bundles of long glass fibers. The long fibers have a length that extends from one side surface 110b, 110b perpendicular to the X direction of the sleeper 100 to the other. When the sleeper body 110 includes fiber bundles, the cured resin material is impregnated into the gaps between the fibers of the fiber bundles. The cured resin is preferably a cured urethane resin, more preferably a cured thermosetting urethane resin. The cured resin is preferably a foamed resin. The cured resin is more preferably a urethane foam containing bubbles, which is a cured urethane resin. The synthetic sleeper is more preferably a urethane foam reinforced with long glass fibers (hereinafter also referred to as "long glass fiber reinforced urethane foam"). Synthetic sleepers may contain solid fillers such as silica sand, fly ash, or rubber chips.

[0012] When the cured resin is a foamed resin, the specific gravity of the sleeper body 110 is preferably 0.64 to 0.84. If the specific gravity of the sleeper body 110 is equal to or greater than the lower limit, the mechanical strength of the sleeper 100 is increased, and if it is equal to or less than the upper limit, the sleeper 100 becomes lighter. Furthermore, if the specific gravity of the sleeper body 110 is equal to or less than the upper limit, wear due to contact with ballast is more likely to occur, which is also preferable in that the application of the present invention is more effective. The specific gravity of the sleeper body 110 can be adjusted by, for example, the density of the cured resin and the content of the reinforcing fibers. The density of the cured resin can be adjusted by the amount of foaming agent, the combination of types, etc.

[0013] The sleeper body 110 can be manufactured by a known method, which will be described later. The sleeper body 110 may be a commercially available product. For example, Eslon Neo Lumber FFU (registered trademark, manufactured by Sekisui Chemical Co., Ltd., hereinafter also referred to as "FFU"), which is a long glass fiber reinforced urethane foam, can be used. FFU is a material made by reinforcing a thermosetting urethane resin foam with long glass fibers.

[0014] <Abrasion resistant part> The wear-resistant portion 120 contains an elastomer. The Shore A hardness of the elastomer is preferably 60 or more and 95 or less. When the Shore A hardness of the elastomer is equal to or greater than the above-mentioned lower limit, the wear resistance is excellent. In addition, it is easy to prevent ballast from cutting into the wear-resistant portion 120. If ballast cuts into the wear-resistant portion 120 when a train passes, the rail will move up and down excessively. Furthermore, if the ballast continues to cut into the wear-resistant portion 120, it will lead to dimensional changes in the sleepers. On the other hand, when the Shore A hardness of the elastomer is equal to or less than the above-mentioned upper limit, the ballast is less likely to wear out.

[0015] As the elastomer, known elastomers can be used, such as urethane elastomers and polyester elastomers. In particular, urethane elastomers are preferred, and two-component curing urethane elastomers are more preferred. Examples of the polyol component constituting the two-component curing urethane elastomer include polyether polyol and polyester polyol. Examples of the isocyanate component include MDI (diphenylmethane diisocyanate) and HDI (hexamethylene diisocyanate).

[0016] The elastomer of the wear-resistant portion may be either a non-foamed or foamed elastomer, with a non-foamed elastomer being preferred in terms of dimensional stability and the ease of preventing ballast from biting into the wear-resistant portion. The wear-resistant portion may contain a filler (for example, calcium carbonate, glass powder, silica sand, rubber chips, etc.) in addition to the elastomer.

[0017] On the underside 110a of the sleeper body 110, multiple rectangular wear-resistant portions 120 are present at equal intervals in the X direction. In this specification, the areas where no wear-resistant portions 120 are present are referred to as non-existent portions 130. In this embodiment, the non-existent portions 130 are exposed portions where the outer surface of the sleeper body 110 is exposed. The wear-resistant portions 120 have a certain thickness, and a step is present at the boundary between the wear-resistant portions 120 and the non-existent portions 130. The ratio of the total area of ​​the wear-resistant portions 120 present on the underside 110a of the sleeper body 110 to the area of ​​the underside 110a is greater than 70% and less than 95%, and preferably 80% to 90%. When the ratio of the total area of ​​the wear-resistant portions 120 is equal to or greater than the lower limit, the wear resistance is improved. When it is equal to or less than the upper limit, the ballast lateral resistance is improved by part of the ballast penetrating into the non-existent portions 130.

[0018] The distance A between the wear-resistant portions 120 in the X direction on the underside 110a of the sleeper body 110 is preferably 10 mm or more and 50 mm or less. The distance A between the wear-resistant portions 120 in the X direction is the width of the non-existence portion 130 in the X direction. When the distance A (width of the non-existence portion 130) is equal to or greater than the lower limit, a portion of the ballast digs into the non-existence portion 130, thereby improving the ballast bed lateral resistance. When the distance A is equal to or less than the upper limit, the wear-resistant portion 120 improves the wear resistance.

[0019] The thickness T of the wear-resistant portion 120 is preferably 1 mm or more and 20 mm or less. In this specification, the thickness of the wear-resistant portion 120 on the lower surface 110a, which is the XY plane, is the thickness of the wear-resistant portion 120 in the Z direction. The same applies to the other surfaces. When the thickness T of the wear-resistant portion 120 is equal to or greater than the above lower limit, the wear resistance is improved. When the thickness T is equal to or less than the upper limit, the depth of ballast excavation required to install the sleeper 100 can be prevented from increasing.

[0020] <Manufacturing method for railway sleepers> The sleeper 100 of this embodiment can be manufactured by applying a curable elastomer composition to the region of the underside 110a of the sleeper body 110 where the wear-resistant portion 120 is to be provided, to form a coating film (application step), and then curing the coating film (curing step). An example of a method for applying the curable elastomer composition only to the region where the wear-resistant portion 120 is to be provided is a method in which a masking material is first attached in a peelable manner to the region of the underside 110a that will become the wear-resistant portion 130, and then the curable elastomer composition is applied to the entire underside 110a in the application step.

[0021] The masking material is not particularly limited. For example, a plate-shaped member having the same thickness as the thickness T of the wear-resistant portion 120 may be attached to the lower surface 110a with a removable adhesive tape. The curable elastomer composition may be a one-component composition or a two-component composition having a base agent and a curing agent. When a two-component curable elastomer composition is used, a mixed liquid (coating liquid) of the base agent and the curing agent is applied in the coating step. The method for applying the curable elastomer composition in the application step is not particularly limited, and may be any known application means such as a spray coater, a roll coater, a die coater, or a brush.

[0022] FIG. 3 is a schematic diagram showing an example of a coating device using a die coater, where (a) is a front view, (b) is a plan view, and (c) is a side view. The coating device of this example has a die 201 equipped with an outlet 201a for discharging the coating liquid, and a moving means 202 for moving the die 201 parallel to the coating surface 210 while maintaining a constant clearance c between the outlet 201a and the coating surface 210. For example, the coating liquid is a curable elastomer composition, and the coating surface 210 is the lower surface 110 a of the sleeper body 110 .

[0023] A masking material 230 is applied in advance to the area of ​​the coating surface 210 that will become the non-existence portion 130. A coating liquid (curable elastomer composition) is supplied to the die 201, and while the die 201 is moved in the longitudinal direction (X direction) of the sleeper body 110, the coating liquid is discharged from the discharge port 201a to form a coating film. The thickness of the coating film can be adjusted by the clearance C between the discharge port 201a and the coating surface 210. It is preferable that the clearance C and the thickness of the masking material 230 are the same. The width of the wear-resistant portion 120 in the Y direction can be adjusted by the width W of the discharge port 201a in the Y direction. In this example, the width W of the discharge port 201a is the same as the width of the sleeper body 110 in the Y direction.

[0024] The curing process for curing the coating film is not particularly limited. After the coating film is cured, the masking material is peeled off, thereby forming the abrasion-resistant portion 120 and the non-existence portion 130.

[0025] The wear-resistant portion 120 thus formed is in close contact with and integrated with the underside 110a of the sleeper body 110. A portion of the curable elastomer composition forming the wear-resistant portion 120 may be cured while impregnated into the surface of the sleeper body 110, or may be cured while being compatible with the surface of the sleeper body 110. It is preferable that both the wear-resistant portion 120 and the sleeper body 110 are made of a material containing urethane resin, as this allows them to be more firmly integrated. For example, it is preferable that the wear-resistant portion 120 is made of a urethane elastomer, and the sleeper body 110 is made of a synthetic sleeper made of fiber-reinforced resin containing reinforcing fibers and a cured resin, the cured resin containing a thermosetting urethane resin.

[0026] <Manufacturing method of the sleeper body> FIG. 4 is a schematic diagram showing an example of a manufacturing system suitable for manufacturing a synthetic sleeper (sleeper body) made of a long glass fiber reinforced urethane foam. The manufacturing system 1a has a base liquid tank 11, a hardener liquid tank 12, a supply device 15, an impregnation machine 16, and a molding passage 19. In addition, the manufacturing system 1a has a base liquid pump 21 that supplies the base liquid 1 stored in the base liquid tank 11 to the supply device 15, and a hardener liquid pump 22 that supplies the hardener liquid 2 stored in the hardener liquid tank 12 to the supply device 15. In the manufacturing system 1a, a fiber bundle 6 in which long fibers are aligned in one direction is continuously transported in one direction (X direction) by a transport means (not shown).

[0027] The impregnation machine 16 can be composed of, for example, an impregnation plate 16a and a plurality of kneading plates 16b. An endless belt may be used instead of the impregnation plate 16a. A temperature regulator may be provided to adjust the temperature of the impregnation plate 16a or the endless belt to a predetermined temperature.

[0028] As shown in FIG. 5, the forming passage 19 is formed by surrounding the four sides with the surfaces of four metal belts 19a. The metal belt 19a is heated (for example, to 30 to 80° C.) to thermally harden and foam the resin-impregnated fiber bundle 7 passing through the molding passage 19.

[0029] A method for manufacturing the sleeper body 110 using the manufacturing system 1a will be described. A main liquid 1 is supplied to a supply device 15 by a main liquid pump 21, and a curing agent liquid 2 is supplied to a curing agent liquid pump 22. The main liquid 1 and the curing agent liquid 2 are mixed in the supply device 15 to form a resin composition 5. When the resin composition 5 is to be a foamable resin composition, a foaming agent is added to the resin composition 5. The resin composition 5 is supplied from the supply device 15 to the fiber bundle 6 in progress (merging step). In the merging step, the resin composition 5 may be sprayed onto the fiber bundle 6 using a spraying device, for example.

[0030] Next, the fiber bundle 6 supplied with the resin composition 5 is treated in an impregnation machine 16. In the impregnation machine 16 shown in Fig. 4, the fiber bundle 6 is kneaded on an impregnation plate 16a using a kneading plate 16b, thereby impregnating the fiber bundle 6 with the resin composition 5 and producing a resin-impregnated fiber bundle 7 (impregnation step).

[0031] Next, the resin-impregnated fiber bundle 7 is passed through a molding passage 19. While the resin-impregnated fiber bundle 7 passes through the molding passage 19, the impregnated resin composition 5 is cured to form a long molded body 111 (curing step). If the resin composition 5 is a foamable resin composition, the curing step includes a foaming operation. The obtained molded body 111 is cut to an appropriate length to form a sleeper body 110 (cutting step).

[0032] According to this embodiment, a wear-resistant layer is not provided over the entire underside 110a of the sleeper body 110, but instead multiple wear-resistant portions 120 and non-existence portions 130 where no wear-resistant portions 120 are present are provided at a predetermined area ratio, thereby achieving both the effect of improving wear resistance due to the wear-resistant portions 120 and the effect of improving ballast lateral resistance due to ballast digging into the non-existence portions 130. In addition, by forming the wear-resistant portion 120 by applying a curable elastomer composition to the area where the wear-resistant portion 120 is to be provided and then curing it, the wear-resistant portion 120 and the sleeper body 110 can be integrated without using adhesives, bolts, or other bonding means.

[0033] <Modification> In the above embodiment, the wear-resistant portion is provided only on the underside 110a of the sleeper body 110, but it may also be provided on outer surfaces other than the underside 110a. Since there is a lot of contact with ballast, it is preferable to provide it on at least one of the side surfaces (side surface 110b perpendicular to the X direction and side surface 110c perpendicular to the Y direction). Wear-resistant portions may be provided on the entire side surface of the sleeper body 110, or wear-resistant portions of any shape and non-existent portions may be provided.

[0034] 6 and 7 show an example in which, as in the above embodiment, a wear-resistant portion 120 is provided on the underside 110a of the sleeper body 110, and furthermore, a wear-resistant portion 121 is provided on the entire surface of each of the side surfaces 110b, 110b perpendicular to the X direction. No non-existent portion 130 exists on the side surface 110b. 6 is a plan view of the sleeper as viewed from the bottom side, and FIG. 7 is a cross-sectional view taken along line QQ in FIG. According to this example, the wear-resistant portion 121 is also provided on the side surface 110b, so that the wear resistance of the sleeper 100 is further improved.

[0035] In the above embodiment, it is possible to appropriately change the shapes of the wear-resistant portion and the non-existent portion provided on the underside 110a of the sleeper body 110. Figures 8 to 10 are plan views of the sleeper as viewed from the underside. In the above embodiment, of the four sides of the rectangular wear-resistant portion 120, the side perpendicular to the X direction is adjacent to the non-existence portion 130. However, as shown in FIG. 8, of the four sides of the rectangular wear-resistant portion 122, the side perpendicular to the X direction may be adjacent to the non-existence portion 131, and further the side perpendicular to the Y direction may be adjacent to the non-existence portion 132. In this example, the non-existence portion 131 extends continuously in the Y direction, and the non-existence portion 132 extends continuously in the X direction. The distance C between the wear-resistant portion 122 and the edge of the sleeper body 110 in the Y direction is preferably 3 mm or more and 20 mm or less, and more preferably 5 mm or more and 15 mm or less. When the distance C is equal to or greater than the above-mentioned lower limit, the wear-resistant portion 122 is excellent in improving the ballast lateral resistance. When the distance C is equal to or less than the upper limit, the wear-resistant portion 122 is excellent in improving the wear resistance.

[0036] 9 shows an example in which multiple wear-resistant portions 123 are present at intervals in both the X and Y directions, and non-existent portions 133, 134, and 135 are present in a lattice pattern. In this example, of the four sides of the rectangular wear-resistant portion 123, the side perpendicular to the X direction is adjacent to the non-existent portion 133, and the two sides perpendicular to the Y direction are adjacent to the non-existent portions 134 and 135, respectively. The non-existent portion 133 extends continuously in the Y direction, and the non-existent portions 134 and 135 extend continuously in the X direction. The distance A between the abrasion-resistant portions 123 in the X direction and the distance B between the abrasion-resistant portions 123 in the Y direction are preferably 10 mm or more and 50 mm or less, respectively. The distance B is the width of the abrasion-resistant portion 135 in the Y direction. When the distance A (width of the non-existence portion 133) and the distance B (width of the non-existence portion 135) are equal to or greater than the lower limit values, a portion of the ballast will dig into the non-existence portions 133, 135, thereby improving the ballast bed lateral resistance. When the distance A is equal to or less than the upper limit values, the wear-resistant portion 123 will have an excellent effect of improving the wear resistance. The distance C between the wear-resistant portion 123 and the edge of the sleeper body 110 in the Y direction is preferably 3 mm or more and 20 mm or less, and more preferably 5 mm or more and 15 mm or less. The distance C is the width of the non-existence portion 134 in the Y direction. When the distance C is equal to or greater than the above-mentioned lower limit, the wear-resistant portion 123 is excellent in improving the ballast lateral resistance. When the distance C is equal to or less than the upper limit, the wear-resistant portion 123 is excellent in improving the wear resistance.

[0037] FIG. 10 shows an example in which, of the four sides of the parallelogram-shaped wear-resistant portion 124, the side intersecting the X direction is adjacent to a non-existence portion 136, and the side perpendicular to the Y direction is adjacent to a non-existence portion 137. The non-existence portion 136 extends continuously in a diagonal direction intersecting both the X direction and the Y direction, and the non-existence portion 137 extends continuously in the X direction. The distance A between the wear-resistant portions 124 in the X direction is preferably 10 mm or more and 50 mm or less. If the distance A (the width of the non-existence portions 136) is equal to or more than the above-mentioned lower limit, a portion of the ballast will dig into the non-existence portions 136, thereby improving the ballast bed lateral resistance. If the distance A is equal to or less than the upper limit, the wear-resistant portions 124 will improve the wear resistance. The distance C between the wear-resistant portion 124 and the edge of the sleeper body 110 in the Y direction is preferably 3 mm or more and 20 mm or less, and more preferably 5 mm or more and 15 mm or less. When the distance C (the width of the non-existence portion 137) is equal to or greater than the above-mentioned lower limit, the wear-resistant portion 124 is excellent in improving the ballast lateral resistance. When it is equal to or less than the upper limit, the wear-resistant portion 124 is excellent in improving the wear resistance.

[0038] In the above example, the wear-resistant portion is rectangular, but is not limited thereto. For example, the wear-resistant portion may be polygonal, circular, or irregularly shaped, such as an island, and the area other than the wear-resistant portion may be an absent portion. If the distance between the wear-resistant portions is not constant in the X, Y, or Z directions, it is sufficient that the minimum and maximum widths are within the above-mentioned preferred ranges. [Example]

[0039] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

[0040] (Materials used) · Sleeper body: Sleeper body made of long glass fiber reinforced polyurethane foam (FFU), specific gravity 0.74, length in X direction 2400 mm, width in Y direction 230 mm, thickness in Z direction 150 mm. Two-component curing urethane elastomer: A cured product of a two-component curing elastomer composition consisting of a base agent containing a polyether polyol-based prepolymer and a curing agent containing monomeric MDI. The Shore A hardness of the cured product is 80.

[0041] Example 1 In this example, a sleeper 100 having the configuration shown in FIGS. 1 and 2 was manufactured. That is, a plurality of wear-resistant portions 120, each rectangular in plan view, were formed at equal intervals along the X direction on the underside 110a of the sleeper body 110. Each wear-resistant portion 120 was 240 mm long in the X direction, 230 mm wide in the Y direction, and 3 mm thick in the Z direction. The width A of the non-existent portion 130 between adjacent wear-resistant portions 120 was 30 mm. The total area of ​​the wear-resistant portions 120 was 90% of the area of ​​the underside 110a of the sleeper body 110.

[0042] The sleeper 100 was manufactured using a coating device having the configuration shown in FIG. First, the sleeper body 110 was positioned with the underside 110a facing upward. A 3 mm thick resin plate was attached with double-sided tape as a masking material 230 to the area of ​​the underside 110a where the wear-resistant portion 120 would not be provided, i.e., the area that would become the non-existence portion 130. The base liquid and curing agent liquid of the two-component curable elastomer composition were mixed in a batch mixer, and the uncured mixed liquid (coating liquid) was supplied to the die 201 of the coating device. In the coating device, the width W of the discharge port 201a was 230 mm, and the clearance C was 3 mm. The die 201 of the coating device was placed at the end of the longitudinal direction (X direction) of the sleeper body 110, and while moving the die 201 in the X direction, the uncured mixed liquid was discharged from the discharge port 201a and coated to form a coating film 3 mm thick. After heating and curing the coating film, the masking material 230 was removed, and a sleeper 100 having the sleeper body 110 and the wear-resistant portion 120 was obtained.

[0043] Example 2 In this example, a sleeper having the configuration shown in Figures 6 and 7 was manufactured. A wear-resistant portion 120 was formed on the underside 110a of the sleeper body 110 in the same manner as in Example 1. Furthermore, the uncured mixed liquid was applied to the entire surface of the side surface 110b perpendicular to the X direction of the sleeper body 110, and cured to form a wear-resistant portion 121 with a thickness of 3 mm, thereby obtaining the sleeper of this example. [Explanation of symbols]

[0044] 1a Manufacturing System 6 Fiber bundles 7 Resin-impregnated fiber bundle 19 Molding passage 100 sleepers 110 Sleeper body 110a Bottom side 110b side 110c side 110d top surface 111 Molded body 120, 121, 122, 123, 124 Wear-resistant part 130, 131, 132, 133, 134, 135, 136, 137 non-existent part 201 Die 201a Discharge port 202 Transportation 210 Coating surface 230 Masking material

Claims

1. A railway sleeper placed on ballast, comprising: The sleeper has a main body and a wear-resistant portion containing an elastomer, A plurality of the wear-resistant portions are present at least on the underside of the sleeper body at intervals in the longitudinal direction of the sleeper body, A railway sleeper, wherein the total area of ​​the wear-resistant portions present on the lower surface is greater than 70% and less than 95% of the area of ​​the lower surface.

2. 2. The railway sleeper according to claim 1, wherein, on a surface on which a plurality of the wear-resistant portions are present, the distance between the wear-resistant portions in the longitudinal direction of the sleeper body is 10 mm or more and 50 mm or less.

3. 2. A railway sleeper as described in claim 1, wherein on a surface on which a plurality of the wear-resistant portions are present, the wear-resistant portions are spaced apart in both the longitudinal direction of the sleeper body and the width direction perpendicular to the longitudinal direction, and the distance between the wear-resistant portions in the longitudinal direction and the distance between the wear-resistant portions in the width direction are both 10 mm or more and 50 mm or less.

4. 2. The railway sleeper according to claim 1, wherein the sleeper body is made of urethane foam reinforced with long glass fibers.

5. 2. The railway sleeper according to claim 1, wherein the Shore A hardness of the elastomer is 60 or more and 95 or less.

6. 2. The railway sleeper according to claim 1, wherein the thickness of the wear-resistant portion is 1 mm or more and 20 mm or less.

7. 2. The railway sleeper of claim 1, further comprising: the wear-resistant portion present on one or more sides of the sleeper body.

8. 2. The railway sleeper of claim 1, wherein the elastomer is a urethane elastomer.

9. A method for manufacturing a railway sleeper according to any one of claims 1 to 8, A method for manufacturing a railway sleeper, comprising a coating step of applying a curable elastomer composition to the area of ​​the sleeper body where the wear-resistant portion is to be provided to form a coating film, and a curing step of curing the coating film.

10. 10. The method for manufacturing railway sleepers according to claim 9, wherein the curable elastomer composition is a two-component curable elastomer composition having a base agent and a curing agent, and a mixed liquid of the base agent and the curing agent is applied in the application step.

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