High tensile strength composite sleeper, material formulation and its forming method

Abstract

The present application relates to railway engineering construction technical field, especially a kind of high tensile strength composite sleeper, material preparation scheme and its forming method, wherein, high tensile strength composite sleeper includes sleeper body, sleeper core and spike mounting seat. Foaming cavity is provided in sleeper body. Sleeper core is foaming body, and it is formed in foaming cavity. After foaming process is finished, spike mounting seat is surrounded by solidified sleeper core. Spike mounting seat is combined by top plate, bottom plate and connecting transition piece. Threaded mounting hole for screw spike is formed on spike mounting seat. In this way, on the one hand, when rail load, pulling force is transmitted to spike mounting seat via screw spike, because spike mounting seat is always subjected to the stability of holding force from sleeper core, pulling force can be effectively balanced;On the other hand, after foaming, cold solidification sleeper core can be left in foaming cavity, and subsequent need not to be executed to pull out, cleaning operation, so that the manufacturing cycle of composite sleeper can be significantly shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of railway engineering construction technology, and particularly relates to a high tensile strength composite sleeper, a material preparation scheme and a forming method thereof. BACKGROUND

[0002] The sleeper is an indispensable material in the field of railway transportation, which is used to support the railway rail and keep the track gauge and horizontal direction geometric shapes between two or more rails in line with the design requirements of the engineering blueprint, and also makes various loads borne by the rail evenly distributed on the sleeper foundation. Therefore, the threaded spike between the rail and the sleeper should have good perpendicularity, and the sleeper should have good tensile strength.

[0003] In recent years, a large number of enterprises in China have carried out a large number of experimental researches on how to improve the tensile strength of the sleeper. For example, Zhongge Composite Material (Nantong) Co., Ltd. developed a sleeper (Chinese invention patent authorization announcement number CN104652182B) during 2014-2015. After actual experimental verification, it achieved very high tensile strength and passed the CMA test. The improved sleeper is composed of a sleeper body and a sleeper core. The sleeper body material is a fiber reinforced resin based composite material, and the sleeper core is composed of a plurality of fiber reinforced resin based composite material profiles and foaming material. When the sleeper body and the sleeper core are compounded, the bolt guide file of the sleeper core composite material profile is embedded in the sleeper body. Its process procedure is more and complex. When the sleeper body and the sleeper core are compounded, the sleeper core composite material profile may be inclined, so that one end of the bolt guide file of the sleeper core composite material profile cannot be embedded in the sleeper body, affecting the overall strength of the sleeper. In the nut sleeve installation method, in examples 1-3, the bolt guide file of the sleeper core composite material profile is drilled through the sleeper body to the lower part, then the nut sleeve is installed in the hole or the epoxy resin is cast into the hole to obtain the bolt thread hole. In the drilling process, it is difficult to ensure the perpendicularity of the nut sleeve installation hole. From the drawings in the specification, the installed nut sleeve is a single nut sleeve, and the contact surface between the upper plane of the nut sleeve and the bottom plane of the upper surface of the sleeper body is small. When the bolt spike tension reaches a high value or a peak value, the contact surface between the nut sleeve and the sleeper body is locally easily damaged. The upper plane of the nut sleeve or the epoxy resin cast nut sleeve is flush with the upper surface of the sleeper body. When the bolt spike tension reaches a certain value, the nut sleeve is likely to be pulled out, causing safety hazards. In example 4, the nut sleeve installation method is to hollow the foaming material at both ends of the sleeper, then embed the metal bracket into the required position of the sleeper body, pass the bolt through the bolt hole from the upper surface of the sleeper body, screw it into the threaded hole of the metal bracket, and then perform secondary foaming treatment on the hollowed part at both ends of the sleeper body. With the solidification of the foaming material, the metal bracket is positioned, and the bolt is removed by loosening. As known, low-density foaming material is easy to be executed to be hollowed, but it has no structural strength; and high-density foaming material has good structural strength after solidification, but it is difficult to be completely hollowed from both ends of the sleeper. Even if the high-density foaming material is forced to be hollowed, the inner cavity surface of the sleeper body will be damaged, and the overall structural strength of the sleeper will be reduced. Therefore, it is urgent for technical personnel to solve the above problems. SUMMARY

[0004] Therefore, the inventors designed a high tensile strength composite sleeper to solve the above problems and defects.

[0005] In order to solve the above technical problems, the present application relates to a high tensile strength composite sleeper, comprising a sleeper body, a sleeper core and a spike mounting seat. The sleeper body is a hollow structure, and a foaming cavity is arranged in the sleeper body. The sleeper core is a foaming body, which is formed in the foaming cavity. Before the foaming process is performed, the open end of the sleeper body is sealed, and the spike mounting seat is pre-assembled in the foaming cavity. After the foaming process is completed, the sleeper core in a solidified state surrounds the spike mounting seat. The spike mounting seat comprises a top plate, a bottom plate and a connecting transition piece. The top plate and the bottom plate are arranged in parallel and are spaced apart at a certain distance. The connecting transition piece connects the top plate and the bottom plate, and is perpendicular to the top plate. A threaded mounting hole is formed on the spike mounting seat, and the threaded mounting hole is used for rotating the threaded spike, crossing the top plate and penetrating into the connecting transition piece to a certain depth. An installation through hole is formed on the top wall of the sleeper body, and the installation through hole is used for allowing the threaded spike to pass through freely.

[0006] As a further improvement of the disclosed technical solution of the present application, the number of connecting transition pieces is consistent with the number of threaded mounting holes. Assuming that the number of threaded mounting holes is N, N≥2, and the threaded mounting holes are uniformly distributed along the length direction of the top plate.

[0007] As a further improvement of the disclosed technical solution of the present application, when the spike mounting seat is installed in place relative to the foaming cavity, the top plate and the bottom plate are respectively in contact with the top wall and the bottom wall of the foaming cavity.

[0008] As a further improvement of the disclosed technical solution of the present application, a first upper strip-shaped guide groove and a first lower strip-shaped guide groove are respectively formed on the top wall of the top plate and the bottom wall of the bottom plate. The first upper strip-shaped guide groove and the first lower strip-shaped guide groove are respectively formed on the top wall and the bottom wall of the foaming cavity. The first upper strip-shaped guide groove is matched with an upper strip-shaped guide protrusion, and the first lower strip-shaped guide groove is matched with a lower strip-shaped guide protrusion.

[0009] As a further improvement of the disclosed technical solution of the present application, the high tensile strength composite sleeper further comprises a first end cover and a second end cover. The first end cover and the second end cover are used to seal the two open ends of the sleeper body.

[0010] As a further improvement of the disclosed technical solution of the present application, a first plug-in body matched with the cross-sectional shape of the foaming cavity is formed on the first end cover. A second plug-in body matched with the cross-sectional shape of the foaming cavity is formed on the second end cover. When the first end cover and the second end cover are assembled in place relative to the sleeper body, the first plug-in body and the second plug-in body are embedded in the foaming cavity.

[0011] As a further improvement of the disclosed technical solution, a second upper strip-shaped guiding recess is formed on the top wall of the first plug-in body and is matched with the upper strip-shaped guiding protrusion, and a second lower strip-shaped guiding recess is formed on the bottom wall of the first plug-in body and is matched with the lower strip-shaped guiding protrusion. A third upper strip-shaped guiding recess is formed on the top wall of the second plug-in body and is matched with the upper strip-shaped guiding protrusion, and a third lower strip-shaped guiding recess is formed on the bottom wall of the second plug-in body and is matched with the lower strip-shaped guiding protrusion.

[0012] As a further improvement of the disclosed technical solution, the high-tensile-strength composite sleeper further comprises a first plug-in member and a second plug-in member. The first end cover is fixedly connected to one open end of the sleeper body by the first plug-in member, and the second end cover is fixedly connected to the other open end of the sleeper body by the second plug-in member. A first plug-in hole matched with the first plug-in member and a second plug-in hole are respectively formed on the first plug-in body at the position of the one open end of the sleeper body. A third plug-in hole matched with the second plug-in member and a fourth plug-in hole are respectively formed on the second plug-in body at the position of the other open end of the sleeper body.

[0013] As a further improvement of the disclosed technical solution, before the fixed connection of the first end cover, the second end cover and the sleeper body is realized, an adhesive is applied on the first plug-in member and the second plug-in member in advance.

[0014] Furthermore, the application also discloses a material preparation scheme for preparing the high-tensile-strength composite sleeper. The sleeper body is made of a fiber-reinforced resin-based composite material by pultrusion. The sleeper core is made of a foamed polyurethane resin mixture by foaming. The spike mounting seat is made of a metal material by pressure casting or casting, or made of an engineering plastic by molding.

[0015] As a further improvement of the disclosed technical solution, the fiber-reinforced resin-based composite material comprises a resin body and a fiber mixture. The resin body is selected from any one of a vinyl ester resin mixture and a polyurethane resin mixture. The fiber mixture is made of a fiber yarn, a notched steel wire and a fiber felt.

[0016] As a further improvement of the disclosed technical solution, when the resin body is selected as the vinyl ester resin mixture, the weight ratio of the resin body is 25% to 32%, and the weight ratio of the fiber mixture is 68% to 75%.

[0017] As a further improvement of the disclosed technical solution, the formula of the vinyl ester resin mixture is as follows according to the weight ratio:

[0018] vinyl ester resin: 18.9% to 24.2%;

[0019] polyvinyl acetate: 3.34% to 4.27%;

[0020] Bis(4-tert-butylcyclohexyl) peroxydicarbonate: 0.07% to 0.086%;

[0021] Benzoyl peroxide: 0.11% to 0.138%;

[0022] Tert-butyl peroxybenzoate: 0.07% to 0.086%;

[0023] Isobutyl methyl ketone peroxide: 0.18% to 0.24%;

[0024] Kaolin: 0.55% to 0.7%;

[0025] Ceramic powder: 0.55% to 0.7%;

[0026] Color paste: 0.89% to 1.15%;

[0027] Release agent: 0.34% to 0.43%;

[0028] The formulation of the fiber mixture is as follows by weight ratio:

[0029] Glass fiber yarn: 19.56% to 21.66%;

[0030] Carbon fiber yarn: 6.52% to 7.22%;

[0031] Notched steel wire: 6.52% to 7.22%;

[0032] Multi-axial glass fiber woven felt or mesh cloth: 24.78% to 27.23%;

[0033] Multi-axial carbon fiber woven felt or mesh cloth: 10.62% to 11.67%;

[0034] Or the formulation of the fiber mixture is as follows:

[0035] Glass fiber yarn: 11.41% to 12.63%

[0036] Aramid fiber yarn: 14.67% to 16.25%

[0037] Notched steel wire: 6.52% to 7.22%

[0038] Multi-axial glass fiber woven felt or mesh cloth: 14.16% to 15.56%

[0039] Multi-axial aramid woven felt or mesh cloth: 21.24% to 23.34%.

[0040] As another modification of the disclosed technical solution, when the resin body is selected as the polyurethane resin mixture, the weight ratio of the resin body is 15% to 20%, and the weight ratio of the fiber mixture is 80% to 85%.

[0041] As a further improvement of the disclosed technical solution, the formula of the fiber mixture is as follows in terms of weight ratio:

[0042] Glass fiber yarn: 11.54% to 12.24%;

[0043] Basalt fiber yarn: 9.63% to 10.2%;

[0044] Aramid fiber yarn: 9.63% to 10.2%;

[0045] Notched steel wire: 7.7% to 8.16%;

[0046] Multi-axial glass fiber woven felt or mesh cloth: 16.6% to 17.68%;

[0047] Multi-axial basalt woven felt or mesh cloth: 12.45% to 13.26%;

[0048] Multi-axial aramid woven felt or mesh cloth: 12.45% to 13.26%;

[0049] The formula of the polyurethane resin mixture is as follows in terms of weight ratio:

[0050] Polyol: 6.57% to 8.76%;

[0051] Isocyanate: 8.27% to 11.04%;

[0052] Ceramic powder: 0.16% to 0.2%.

[0053] As a further improvement of the disclosed technical solution, the formula of the foamed polyurethane resin mixture is as follows in terms of weight ratio:

[0054] Polyol: 39% to 43%;

[0055] Isocyanate: 39% to 43%;

[0056] Ceramic powder: 1.2% to 2.0%

[0057] Chopped glass fiber yarn: 12.8% to 20%.

[0058] In addition, the application also discloses a molding method for preparing the high-tensile-strength composite sleeper.

[0059] S1, according to the design blueprint requirements, performing a cutting operation to prepare a sleeper body of a certain length;

[0060] S2, when the stud mounting seat is formed by the die casting or casting process, a machining operation is performed on it to form the threaded mounting hole on the stud mounting seat; or, in the process of forming the stud mounting seat by the die pressing process, the threaded mounting hole is formed by die pressing together; the pillow body is machined to form the foamed material injection hole, the foamed material exhaust hole and the mounting through hole on the top wall, all of which are communicated with the foaming cavity;

[0061] S3, the inside of the foaming cavity and the outer side wall of the stud mounting seat are cleaned and cleaned;

[0062] S4, the stud mounting seat is inserted into the foaming cavity, and the threaded mounting hole and the mounting through hole are aligned;

[0063] S5, the threaded stud is coated with a release agent on the outer side wall, and is screwed into the threaded mounting hole;

[0064] S6, the two open ends of the pillow body are sealed;

[0065] S7, the foamed polyurethane resin mixture is injected into the foaming cavity through the foamed material injection hole until the excess foamed polyurethane resin mixture is overflowed through the foamed material exhaust hole, and the foamed polyurethane resin mixture is cured and formed after a certain time;

[0066] S8, the threaded stud is screwed out of the threaded mounting hole, and the cured foamed polyurethane resin mixture overflowed through the foamed material exhaust hole is removed.

[0067] As a further improvement of the disclosed technical solution of the present application, the pillow body and the stud mounting seat are preheated before the foamed polyurethane resin mixture is injected into the foaming cavity, and the temperature of the two is controlled at 35-40°.

[0068] As a further improvement of the disclosed technical solution of the present application, the diameter of the foamed material injection hole is controlled at 25-35mm; the diameter of the foamed material exhaust hole is controlled at 3-5mm.

[0069] The above technical solution has the following beneficial technical effects in practical application:

[0070] With respect to the innovative structure of the high tensile strength composite sleeper, the design effectively improves the tensile strength of the composite sleeper, and ensures that the steel rail always maintains good connection reliability and stability after assembly. The reason is that the spike mounting seat is hidden in the foaming cavity and is wrapped by the foamed and solidified sleeper core. On the one hand, when the steel rail is loaded, the pulling force is transmitted to the spike mounting seat through the threaded spike. Since there is a large wrapping contact area between the spike mounting seat and the sleeper core, it means that it is always affected by stable wrapping force, which can effectively balance the pulling force and ultimately effectively avoid the phenomenon of damaging the spike mounting seat, causing the spike mounting seat to be pulled out of the sleeper, or damaging the sleeper (the sleeper top wall arches locally due to excessive force). On the other hand, during the preparation of the composite sleeper, the foamed and solidified sleeper core does not need to be removed, which greatly shortens the manufacturing cycle of the composite sleeper and reduces the manufacturing cost. On the other hand, since the spike mounting seat is integrally installed in the foaming cavity, it can also effectively improve the compressive strength of the formed composite sleeper to ensure stable loading of the steel rail and passing trains.

[0071] With respect to the innovative material preparation scheme of the high tensile strength composite sleeper, on the one hand, by optimizing the foaming raw materials, the sleeper core after forming has good structural strength and density, thereby ensuring that the sleeper core always maintains sufficient wrapping force on the spike mounting seat, and ensuring that the steel rail and the composite sleeper remain in a stable assembly state for a long period of time after being fastened by the threaded spike. On the other hand, it ensures that the foamed and solidified sleeper core has a very high bonding strength relative to the sleeper body and the spike mounting seat, thereby preventing the composite sleeper from losing stability due to the pulling force.

[0072] With respect to the innovative forming method of the high tensile strength composite sleeper, on the one hand, the forming step is optimized, and the threaded mounting hole is pre-formed on the spike mounting seat after casting, and the threaded spike is used to limit the installation position before the foaming process is performed, to ensure that it occupies the correct relative position relative to the foaming cavity and the sleeper core after foaming and solidification. In addition, the threaded spike plays a role in plugging the threaded mounting hole to avoid the fluid state foaming raw material from being poured, thereby saving a lot of subsequent cleaning work. On the other hand, by using the threaded spike, the threaded mounting hole also effectively ensures that it maintains good perpendicularity relative to the top wall of the composite sleeper, thereby ensuring that the steel rail can be correctly laid during subsequent track construction, and also improves the stability and reliability of the composite sleeper in supporting the steel rail. BRIEF DESCRIPTION OF DRAWINGS

[0073] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0074] Figure 1 This is a three-dimensional schematic diagram of the high tensile strength composite sleeper of the present invention (only the right half is shown).

[0075] Figure 2 yes Figure 1 Top view (in full schematic view).

[0076] Figure 3 yes Figure 2 AA sectional view.

[0077] Figure 4 yes Figure 2 BB cross-sectional view.

[0078] Figure 5 This is an exploded view of the high tensile strength composite sleeper of the present invention (only the right half is shown).

[0079] Figure 6 This is also a three-dimensional schematic diagram of the high tensile strength composite sleeper in this invention (the sleeper core, first end cap, second end cap, first pin, and second pin are hidden).

[0080] Figure 7 This is a three-dimensional cross-sectional view of the high tensile strength composite sleeper of the present invention (the sleeper core, first end cap, second end cap, first pin and second pin are hidden).

[0081] Figure 8 This is a three-dimensional schematic diagram of the sleeper body in the high tensile strength composite sleeper of the present invention.

[0082] Figure 9 This is a three-dimensional schematic diagram of the full cross-sectional shape of the sleeper body in the high tensile strength composite sleeper of the present invention.

[0083] Figure 10 This is a three-dimensional schematic diagram of the high tensile strength composite sleeper center spike mounting base of the present invention.

[0084] Figure 11 This is a three-dimensional cross-sectional view of the high tensile strength composite sleeper center spike mounting base of the present invention.

[0085] Figure 12 This is a three-dimensional schematic diagram of the first end cap in the high tensile strength composite sleeper of the present invention.

[0086] Figure 13 is a perspective view of the second end cover in the high tensile strength composite sleeper of the present application.

[0087] 1-sleeper body; 11-foaming cavity; 111-upper strip-shaped guiding protrusion; 112-lower strip-shaped guiding protrusion; 12-mounting through hole; 2-sleeper core; 3-nail mounting seat; 31-top plate; 311-first upper strip-shaped guiding groove; 32-bottom plate; 321-first lower strip-shaped guiding groove; 33-connecting transition piece; 331-threaded mounting hole; 332-mobility-enhancing annular groove; 4-first end cover; 41-first plug-in body; 411-second upper strip-shaped guiding groove; 412-second lower strip-shaped guiding groove; 5-second end cover; 51-second plug-in body; 511-third upper strip-shaped guiding groove; 512-third lower strip-shaped guiding groove; 6-first plug-in piece; 7-second plug-in piece. DETAILED DESCRIPTION

[0088] In the description of the present application, it should be understood that the terms "front", "back", "upper", "lower", "left", "right" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0089] In railway construction, composite sleepers are padded between sleeper support beams and steel rails to effectively ensure that the steel rails are laid flat, thereby achieving the design goal of high-speed, stable and safe operation of trains.

[0090] The disclosed content of the present application will be further described in detail below in conjunction with specific embodiments, Figures 1-7 The structure of the high tensile strength composite sleeper is shown in the drawings, and it can be seen that it mainly consists of a sleeper body 1, a sleeper core 2 and a nail mounting seat 3 and the like. Among them, the sleeper body 1 is in a hollow structure, and a foaming cavity 11 (as shown in Figure 9 ) is arranged in it. The sleeper core 2 is a foaming body, which is formed in the foaming cavity 11. Before the foaming process is formally performed, the open end of the sleeper body 1 is sealed, and the nail mounting seat 3 is pre-assembled in the foaming cavity 11, and after the foaming process is completed, it is surrounded by the cured sleeper core 2. The nail mounting seat 3 includes a top plate 31, a bottom plate 32 and a connecting transition piece 33. The top plate 31 and the bottom plate 32 are arranged in parallel and at a certain distance. The connecting transition piece 33 connects the top plate 31 and the bottom plate 32, and it is perpendicular to the top plate 31. Threaded mounting holes 331 (as shown in Figure 10 、 11The threaded mounting hole 331 is formed on the top wall of the sleeper 1, and the mounting through hole 12 (as shown in FIG. 1) for the threaded spike to freely pass through is formed on the threaded mounting hole 331. Figure 9 By adopting the technical scheme, the tensile strength of the composite sleeper is effectively improved, and the connection reliability and stability of the rail are ensured after the rail is assembled. The reason is that the spike mounting seat 3 is hidden in the foaming cavity 11 and is wrapped by the foamed and solidified sleeper core 2. When the rail is loaded, the pulling force is transmitted to the spike mounting seat 3 through the threaded spike. Since the spike mounting seat 3 and the sleeper core 2 have a large wrapping contact area, the spike mounting seat 3 is always subjected to a stable wrapping force, which can effectively balance the pulling force and effectively prevent the spike mounting seat 3 from being damaged, pulled out of the sleeper 1, or the sleeper 1 (the top wall of the sleeper 1 is locally arched) from being damaged due to the pulling force exceeding the limit.

[0091] In addition, it should be noted that during the preparation of the composite sleeper, the foaming process is performed after the spike mounting seat 3 is pre-installed in the foaming cavity 11. That is, the foamed and solidified sleeper core 2 can remain in the foaming cavity 11, and subsequent removal operation is not required, thereby greatly shortening the manufacturing cycle of the composite sleeper and reducing the manufacturing cost.

[0092] Furthermore, as shown in FIG. 1, the two threaded mounting holes 331 arranged along the length direction of the spike mounting seat 3 are formed on each spike mounting seat 3, and the number of the connecting transition pieces 33 is correspondingly two. Figure 3 As shown in FIG. 1, the threaded mounting hole 331 is formed on the top wall of the sleeper 1, and the mounting through hole 12 (as shown in FIG. 1) for the threaded spike to freely pass through is formed on the threaded mounting hole 331.

[0093] In combination with the accompanying drawings, Figure 3 , 4As shown in the diagram, when the spike mounting base 3 is installed in place relative to the foaming cavity 11, its top plate 31 and bottom plate 32 are respectively in contact with the top and bottom walls of the foaming cavity 11. By adopting the above technical solution, on the one hand, because the top and bottom walls of the foaming cavity 11 are stably contacted by the top plate 31 and bottom plate 32 respectively, and under the auxiliary support of the connecting transition piece 33, the compressive strength of the composite sleeper is significantly improved, thereby ensuring stable load-bearing capacity for the rails and passing trains; on the other hand, it avoids the occurrence of "foaming dead corners" and the phenomenon that the fluid foaming material cannot be smoothly and effectively filled due to the small gap space, ensuring that the foamed and cooled sleeper core has good molding quality and overall density.

[0094] To ensure that the inserted rail spike mounting bracket 3 occupies the correct orientation relative to the foaming cavity 11 and to avoid tilting, as a further optimization of the above technical solution, such as Figure 10 , 11 As shown, a first upper strip-shaped guide groove 311 and a first lower strip-shaped guide groove 321 are respectively formed on the top wall of the top plate 31 and the bottom wall of the bottom plate 32. Both the first upper strip-shaped guide groove 311 and the first lower strip-shaped guide groove 321 extend along the length of the rail spike mounting base 3. Correspondingly, upper strip-shaped guide protrusions 111 and lower strip-shaped guide protrusions 112 (e.g., matching the first upper strip-shaped guide groove 311) are formed on the top wall and bottom wall of the foaming cavity 11, respectively. Figure 8 (As shown in the diagram). In this way, when installing the rail spike mounting base 3 into the foam cavity 11, the worker only needs to ensure that the first upper strip-shaped guide groove 311 and the first lower strip-shaped guide groove 321 are aligned with the upper strip-shaped guide protrusion 111 and the lower strip-shaped guide protrusion 112, respectively, and then push the rail spike mounting base 3 in without deviation. The entire operation is convenient and quick. It should also be noted that the presence of the upper strip-shaped guide protrusion 111 and the lower strip-shaped guide protrusion 112 can effectively improve the structural strength of the pillow body 1 (mainly in terms of bending strength).

[0095] In addition, by appendix Figure 10 , 11 As shown in the diagram, multiple friction-enhancing annular grooves 332 are evenly distributed along the length of the connecting transition piece 33 on its peripheral sidewall. Thus, after the pillow core 2 completes its foaming process, these grooves are filled with the cooled, solidified foam material, further strengthening the bond between the rail spike mounting base 3 and the pillow core 2. This means an increased ability of the pillow core 2 to hold the rail spike mounting base 3 in place, effectively preventing the rail spike mounting base 3 from failing to bond with the pillow core 2 due to excessive pull-out force.

[0096] It is known that according to the design common sense, for the purpose of ensuring the foaming process of the pillow core 2 to be implemented smoothly, various schemes can be adopted to achieve the plugging of the two open ends of the pillow body 1, for example: bonding a sealing plate to the end face of the open end or plugging by a plug matched with the cross section of the foaming cavity 1. However, the composite sleeper prepared by the above technical scheme has poor aesthetic appearance, and a large amount of manpower and material resources need to be invested to remove the sealing plate and the plug, and the pillow body 1 is also easily damaged due to improper operation. In view of this, as a further optimization of the above technical scheme, in the present embodiment, as shown in Figure 1 、 2 , 3, 5, the first end cover 4 and the second end cover 5 are used to achieve the plugging operation of the two open ends respectively, and after the composite sleeper is formed, the first end cover 4 and the second end cover 5 are both reserved.

[0097] Further, as shown in Figure 12 、 13 , a first plug-in body 41 matched with the cross-sectional shape of the foaming cavity 11 is formed on the first end cover 4. A second plug-in body 51 matched with the cross-sectional shape of the foaming cavity 11 is formed on the second end cover 5. When the first end cover 4 and the second end cover 5 are assembled in place relative to the pillow body 1, the first plug-in body 41 and the second plug-in body 51 are both embedded in the foaming cavity 11. In this way, on the premise of ensuring that the formed composite sleeper has an aesthetic appearance, the first end cover 4 and the second end cover 5 cooperate to achieve reliable plugging of the foaming cavity 11, thereby preventing the fluid foaming raw material from overflowing through the assembly gap between the first end cover 4, the second end cover 5 and the pillow body 1, and ensuring that the foaming process can be smoothly implemented and developed.

[0098] In order to cater to the design structure form of the pillow body 1, as shown in Figure 12 , a second upper strip-shaped guide groove 411 matched with the upper strip-shaped guide protrusion 111 is formed on the top wall of the first plug-in body 41, and a second lower strip-shaped guide groove 412 matched with the lower strip-shaped guide protrusion 112 is formed on the bottom wall thereof. As shown in Figure 13 , a third upper strip-shaped guide groove 511 matched with the upper strip-shaped guide protrusion 111 is formed on the top wall of the second plug-in body 51, and a third lower strip-shaped guide groove 512 matched with the lower strip-shaped guide protrusion 112 is formed on the bottom wall thereof. In this way, the upper strip-shaped guide protrusion 111 and the lower strip-shaped guide protrusion 112 are formed along the length direction of the pillow body 1, thereby effectively simplifying the design structure of the pillow body 1, and laying a good foundation for the subsequent reduction of control difficulty and improvement of the final pultrusion molding quality.

[0099] As the first end cover 4 and the second end cover 5 are long-term placed on the composite sleeper, in order to avoid the first end cover 4 and the second end cover 5 from being separated from the foaming cavity 11 due to accidental force or exciting force during subsequent transportation, construction and actual application of the composite sleeper, as a further optimization of the above technical scheme, as shown in Figs. 3, 5 and 7, the first end cover 4 is fixedly connected with the left open end of the sleeper body 1 through the first pin member 6, and the second end cover 5 is fixedly connected with the right open end of the sleeper body 1 through the second pin member 7. Figure 1 、 2 In the left open end position of the sleeper body 1, the first end cover 4 is provided with the first insertion hole and the second insertion hole (not shown in the figure) which are matched with the first pin member 6. In the right open end position of the sleeper body 1, the second end cover 5 is provided with the third insertion hole and the fourth insertion hole (not shown in the figure) which are matched with the second pin member 7.

[0100] It should be further noted that before the fixed connection of the first end cover 4, the second end cover 5 and the sleeper body 1 is realized, the first pin member 6 and the second pin member 7 should be smeared with adhesive in advance. In this way, the first pin member 6 and the second pin member 7 can be effectively prevented from being separated from the sleeper body 1 due to exciting force, thereby avoiding the problem of invalid connection of the first end cover 4, the second end cover 5 and the sleeper body 1.

[0101] In addition, the present application also discloses a material preparation scheme for preparing the above-mentioned high-tensile-strength composite sleeper. The sleeper body 1 is made of fiber reinforced resin-based composite material by pultrusion. The sleeper core 2 is made of foamed polyurethane resin mixture by foaming. The spike mounting seat 3 is made of metal material by pressure casting or casting, or made of engineering plastic by molding.

[0102] The fiber reinforced resin-based composite material comprises a resin body and a fiber mixture. The resin body is selected from any one of vinyl ester resin mixture and polyurethane resin mixture. The fiber mixture is made of fiber yarn, notched steel wire and fiber felt.

[0103] The following is the material preparation scheme of the three kinds of strength composite sleepers, specifically:

[0104] Material preparation scheme one: the resin body is selected as vinyl ester resin mixture, and the weight ratio of the resin body is 25% to 32%, and the weight ratio of the fiber mixture is 68% to 75%.

[0105] According to the weight ratio, the formula of the vinyl ester resin mixture is:

[0106] Vinyl ester resin: 18.9% to 24.2%;

[0107] Polyvinyl acetate: 3.34% to 4.27%;

[0108] Di-tert-butylperoxide: 0.07% - 0.086%;

[0109] Benzoyl peroxide: 0.11% - 0.138%;

[0110] Tert-butyl peroxybenzoate: 0.07% - 0.086%;

[0111] Isobutyl methyl ketone peroxide: 0.18% - 0.24%;

[0112] Kaolin: 0.55% - 0.7%;

[0113] Ceramic powder: 0.55% - 0.7%;

[0114] Coloring paste: 0.89% - 1.15%;

[0115] Release agent: 0.34% - 0.43%;

[0116] The formulation of the fiber mixture is as follows by weight ratio:

[0117] Glass fiber yarn: 19.56% - 21.66%;

[0118] Carbon fiber yarn: 6.52% - 7.22%;

[0119] Notched steel wire: 6.52% - 7.22%;

[0120] Multi-axial glass fiber woven felt or mesh cloth: 24.78% - 27.23%;

[0121] Multi-axial carbon fiber woven felt or mesh cloth: 10.62% - 11.67%.

[0122] The formulation of the foaming polyurethane resin mixture used to form the pillow core 2 is as follows by weight ratio:

[0123] Polyol: 39% - 43%;

[0124] Isocyanate: 39% - 43%;

[0125] Ceramic powder: 1.2% - 2.0%

[0126] Chopped glass fiber yarn: 12.8% - 20%.

[0127] Material preparation scheme two: the resin body is also selected as a vinyl ester resin mixture, and the weight ratio of the resin body is 25% - 32%, and the weight ratio of the fiber mixture is 68% - 75%.

[0128] The formulation of the vinyl ester resin mixture is as follows by weight ratio:

[0129] Vinyl ester resin: 18.9% ~ 24.2%;

[0130] Polyvinyl acetate: 3.34% ~ 4.27%;

[0131] Bis (4-tert-butylcyclohexyl) peroxydicarbonate: 0.07% ~ 0.086%;

[0132] Benzoyl peroxide: 0.11% ~ 0.138%;

[0133] Tert-butyl peroxybenzoate: 0.07% ~ 0.086%;

[0134] Isobutyl methyl ketone peroxide: 0.18% ~ 0.24%;

[0135] Kaolin: 0.55% ~ 0.7%;

[0136] Ceramic powder: 0.55% ~ 0.7%;

[0137] Coloring paste: 0.89% ~ 1.15%;

[0138] Release agent: 0.34% ~ 0.43%;

[0139] The formulation of the fiber mixture is as follows:

[0140] Glass fiber yarn: 11.41% ~ 12.63%;

[0141] Aramid fiber yarn: 14.67% ~ 16.25%;

[0142] Notched steel wire: 6.52% ~ 7.22%;

[0143] Multi-axial glass fiber woven felt or mesh cloth: 14.16% ~ 15.56%;

[0144] Multi-axial aramid woven felt or mesh cloth: 21.24% ~ 23.34%.

[0145] The formulation of the foaming polyurethane resin mixture used to form the pillow core 2 by foaming is as follows:

[0146] Polyol: 39% ~ 43%;

[0147] Isocyanate: 39% ~ 43%;

[0148] Ceramic powder: 1.2% ~ 2.0%

[0149] Chopped glass fiber yarn: 12.8% ~ 20%.

[0150] Material preparation scheme three: the resin body is selected as a polyurethane resin mixture, the weight ratio of the resin body is 15% to 20%, and the weight ratio of the fiber mixture is 80% to 85%.

[0151] The polyurethane resin mixture is prepared in the workshop, and the formula is as follows according to the weight ratio:

[0152] Polyol: 6.57% to 8.76%;

[0153] Isocyanate: 8.27% to 11.04%;

[0154] Ceramic powder: 0.16% to 0.2%.

[0155] The formula of the fiber mixture is as follows according to the weight ratio:

[0156] Glass fiber yarn: 11.54% to 12.24%;

[0157] Basalt fiber yarn: 9.63% to 10.2%;

[0158] Aramid fiber yarn: 9.63% to 10.2%;

[0159] Notched steel wire: 7.7% to 8.16%;

[0160] Multi-axial glass fiber woven felt or mesh cloth: 16.6% to 17.68%;

[0161] Multi-axial basalt woven felt or mesh cloth: 12.45% to 13.26%;

[0162] Multi-axial aramid woven felt or mesh cloth: 12.45% to 13.26%;

[0163] The formula of the foaming polyurethane resin mixture used for foaming and forming the pillow core 2 is as follows according to the weight ratio:

[0164] Polyol: 39% to 43%;

[0165] Isocyanate: 39% to 43%;

[0166] Ceramic powder: 1.2% to 2.0%

[0167] Chopped glass fiber yarn: 12.8% to 20%.

[0168] In actual implementation, the above three material preparation schemes all achieve excellent technical effects, specifically: on the one hand, through the optimization of the foaming raw material, the pillow core 2 after forming has good structural strength and compactness, thereby ensuring that the pillow core 2 always has sufficient wrapping force on the spike mounting seat 3, and ensuring that the steel rail and the composite sleeper are always in a stable assembled state after being fastened by the threaded spike for a relatively long period of time; on the other hand, the foamed and solidified pillow core 2 is ensured to have extremely high bonding strength with respect to the sleeper body 1 and the spike mounting seat 3, thereby eliminating the phenomenon of premature structural instability of the composite sleeper due to the action of the pulling force; on the other hand, in the forming process of the pillow core 2, ceramic powder and chopped glass fiber yarn with a length of 15-20 mm are selected as fillers, and the chopped glass fiber yarn is arranged in a random manner, thereby greatly improving the mechanical strength of the composite sleeper.

[0169] Here, it is also necessary to note that in the foaming forming process of the pillow core 2, the isocyanate is delivered by one pipe of the injection machine, and the mixture of the polyol, the ceramic powder and the chopped glass fiber yarn is delivered by another pipe of the injection machine. When the two materials are mixed, a large amount of heat will be generated due to the chemical reaction to warm the mixture to about 140°C, which is beneficial to subsequent complete filling of the foaming cavity 11.

[0170] The composite sleeper prepared by the above scheme one is subjected to inspection by the subject group, and the specific test results are as follows

[0171] Summary table of mechanical property test results (comparison results of CMA test data and national standards)

[0172]

[0173]

[0174]

[0175] Note: In the mechanical property test, after the composite sleeper passes the 450kN static load test, a load of 324KN is loaded at the center of the sleeper span, the vibration frequency is 3Hz-5Hz, and the fatigue performance test is carried out. After 50 million, 100 million, 150 million, 200 million and 250 million cycles of detection, respectively, 3 times of static load test are carried out again, and the maximum load is 400kN. After 250 million cycles of fatigue performance test, the mechanical properties of the sleeper all exceed the index values, and the sleeper is not damaged.

[0176] Summary table of physical property test results

[0177] Serial number Inspection item Unit Inspection result Index value 1 Density Kg / m 3 ]] 2090 ≥1200 2 Flame retardancy Grade HB HB 3 Breakdown voltage KV 32 ≥20 4 Surface resistivity Ω / ≥ 1 x 10 10 ]]

[0178] Summary of mechanical property test results

[0179] Serial number Inspection item Unit Inspection result Index value 1 Fatigue performance / 250 million times / 324 KN 200 million times without abnormality 2 Bending load resistance KN 1320 ≥1000 3 Bolt dowel pullout strength KN 75 ≥60

[0180] Note: Since the second and third schemes have only slight differences in the same components and the selection ratio compared with the first scheme, in order to save testing costs, only the composite sleepers prepared by the first scheme are sent for inspection.

[0181] Finally, it should be pointed out that the present application also discloses a molding method for preparing the high-tensile-strength composite sleeper, which comprises the following steps:

[0182] S1. According to the design blueprint requirements, perform the cutting operation to prepare sleepers 1 of a certain length;

[0183] S2. After the spike mounting seat 3 is formed by the die casting or casting process, perform the machining operation to form the threaded mounting hole 331 on the spike mounting seat 3; or, in the process of forming the spike mounting seat 3 by the die pressing process, the threaded mounting hole 331 is formed by die pressing at the same time; machine the sleeper 1 to form the foaming material injection hole, the foaming material exhaust hole (not shown in the figure) and the mounting through hole 12 on the top wall, all of which communicate with the foaming cavity 11; the diameter of the foaming material injection hole is controlled to be 25-35 mm; the diameter of the foaming material exhaust hole is controlled to be 3-5 mm;

[0184] S3. Perform the cleaning operation on the inside of the foaming cavity 11 and the outside wall of the spike mounting seat 3;

[0185] S4. Insert the spike mounting seat 3 into the foaming cavity 11, and make the threaded mounting hole 331 on the spike mounting seat 3 and the mounting through hole 12 opposite to each other;

[0186] S5. Coat the outside wall of the threaded spike with a release agent, and screw it into the threaded mounting hole 331;

[0187] S6. Block the two open ends of the sleeper 1 by the first end cover 4 and the second end cover 5 respectively, and then lock them by the first bolt 6 and the second bolt 7 (it is advisable to coat a layer of adhesive on the first bolt 6 and the second bolt 7 before performing the insertion operation);

[0188] S7. Inject the foaming polyurethane resin mixture into the foaming cavity 11 through the foaming material injection hole until the excess foaming polyurethane resin mixture overflows through the foaming material exhaust hole, wait for a certain time, and the foaming polyurethane resin mixture is cured to form the sleeper core 2;

[0189] S8. Unscrew the threaded spike from the threaded mounting hole 331, and remove the cured foaming polyurethane resin mixture that has overflowed through the foaming material exhaust hole.

[0190] By adopting the technical scheme, on one hand, the forming step is optimized. Before the rail spike mounting seat 3 is loaded into the sleeper 1, the threaded mounting hole 331 is pre-formed. Before the foaming process is performed, the threaded rail spike is used to limit the loading position, so that the threaded mounting hole 331 occupies a correct relative position with respect to the foaming cavity 11 and the sleeper core 2 after foaming and solidification. In addition, the threaded rail spike plays a role of plugging the threaded mounting hole 331, so that the fluid foaming material (i.e. foaming polyurethane resin mixture) is prevented from being poured, thereby saving a large amount of subsequent cleaning work. On the other hand, by using the threaded rail spike, the threaded mounting hole 331 is effectively ensured to have good perpendicularity with respect to the top wall of the composite sleeper, so that the steel rail can be correctly laid in subsequent track laying construction, and the bearing stability and reliability of the composite sleeper to the steel rail are also improved to some extent.

[0191] It should be further noted that, in order to consider that the foaming polyurethane resin mixture can be quickly foamed in the foaming cavity 11 of the sleeper 1, thereby improving the production efficiency, as a further optimization of the technical scheme, before the foaming polyurethane resin mixture is injected into the foaming cavity 11, the sleeper 1, the rail spike mounting seat 3, the first end cover 4 and the second end cover 5 are all subjected to preheating treatment, and the temperature value is controlled at 35-40°. In this way, during the foaming preparation of the sleeper core 2, the preheating operation can effectively ensure that the foaming polyurethane resin mixture can completely fill the foaming cavity 11, thereby ensuring that the sleeper core 2 after foaming and solidification has good forming quality and density.

[0192] The above description of disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high tensile strength composite railway sleeper, comprising a sleeper body, a sleeper core, and a rail spike mounting base; the sleeper body has a hollow structure with a foaming cavity inside; the sleeper core is a foam material formed within the foaming cavity; before the formal foaming process, the open end of the sleeper body is pre-sealed, and the rail spike mounting base is pre-installed in the foaming cavity; after the foaming process is completed, it is surrounded by the solidified sleeper core, characterized in that... The rail spike mounting base includes a top plate, a bottom plate, and a connecting transition member; the top plate and the bottom plate are parallel and spaced apart by a predetermined distance; the connecting transition member connects both the top plate and the bottom plate and is perpendicular to the top plate; a threaded mounting hole is formed on the rail spike mounting base for the threaded rail spike to be screwed in, pass through the top plate, and penetrate to a predetermined depth into the connecting transition member; a mounting through hole is formed on the top wall of the pillow body, corresponding to the threaded mounting hole, for the threaded rail spike to pass through freely; Once the rail spike mounting base is installed in place relative to the foam cavity, the top plate and the bottom plate are respectively in contact with the top and bottom walls of the foam cavity. A first upper strip-shaped guide groove and a first lower strip-shaped guide groove are respectively formed on the top wall of the top plate and the bottom wall of the bottom plate; both the first upper strip-shaped guide groove and the first lower strip-shaped guide groove extend along the length direction of the rail spike mounting seat; correspondingly, an upper strip-shaped guide protrusion adapted to the first upper strip-shaped guide groove and a lower strip-shaped guide protrusion adapted to the first lower strip-shaped guide groove are respectively formed on the top wall and the bottom wall of the foaming cavity; Along its length, multiple friction-enhancing annular grooves are evenly distributed on the peripheral sidewall of the connecting transition piece.

2. The high tensile strength composite sleeper according to claim 1, characterized in that, The number of connecting transition pieces is consistent with the number of threaded mounting holes; and it is assumed that the number of threaded mounting holes is N, N≥2, and they are evenly distributed along the length direction of the top plate.

3. The high tensile strength composite sleeper according to claim 1, characterized in that, It also includes a first end cap and a second end cap; the first end cap and the second end cap are used to seal the two open ends of the pillow body respectively.

4. The high tensile strength composite sleeper according to claim 3, characterized in that, A first insert is formed on the first end cap to match the cross-sectional shape of the foam cavity; a second insert is formed on the second end cap to match the cross-sectional shape of the foam cavity; when the first end cap and the second end cap are assembled in place relative to the pillow body, the first insert and the second insert are both embedded in the foam cavity.

5. The high tensile strength composite sleeper according to claim 4, characterized in that, A second upper strip-shaped guide groove adapted to the upper strip-shaped guide protrusion is formed on the top wall of the first insert, and a second lower strip-shaped guide groove adapted to the lower strip-shaped guide protrusion is formed on its bottom wall; a third upper strip-shaped guide groove adapted to the upper strip-shaped guide protrusion is formed on the top wall of the second insert, and a third lower strip-shaped guide groove adapted to the lower strip-shaped guide protrusion is formed on its bottom wall.

6. The high tensile strength composite sleeper according to claim 5, characterized in that, It also includes a first pin and a second pin; the first end cap is fixedly connected to one open end of the pillow body by means of the first pin, and the second end cap is fixedly connected to the other open end of the pillow body by means of the second pin; a first insertion hole and a second insertion hole adapted to the first pin are respectively formed at the open end of the pillow body and on the first insertion body; a third insertion hole and a fourth insertion hole adapted to the second pin are respectively formed at the other open end of the pillow body and on the second insertion body.

7. The high tensile strength composite sleeper according to claim 6, characterized in that, Before formally fixing the first end cap, the second end cap, and the pillow body, adhesive is applied to both the first and second pins.

8. The high tensile strength composite sleeper according to any one of claims 1-7, characterized in that, The pillow body is pultruded from fiber-reinforced resin-based composite material; the pillow core is foamed from a foamed polyurethane resin mixture; and the rail spike mounting base is die-cast or cast from metal material, or molded from engineering plastic.

9. The high tensile strength composite sleeper according to claim 8, characterized in that, The fiber-reinforced resin matrix composite material includes a resin body and a fiber mixture; the resin body is selected from either a vinyl ester resin mixture or a polyurethane resin mixture; and the fiber mixture is composed of fiber yarn, indented steel wire and fiber felt.

10. The high tensile strength composite sleeper according to claim 9, characterized in that, When the resin body is selected as a vinyl ester resin mixture, the weight percentage of the resin body is 25% to 32%, and the weight percentage of the fiber mixture is 68% to 75%.

11. The high tensile strength composite sleeper according to claim 10, characterized in that, The formulation of the vinyl ester resin mixture by weight ratio is as follows: Vinyl ester resin: 18.9%–24.2%; Polyvinyl acetate: 3.34%–4.27%; Bis(4-tert-butylcyclohexyl) peroxide dicarbonate: 0.07%–0.086%; Benzoyl peroxide: 0.11%~0.138%; tert-butyl peroxide: 0.07%–0.086%; Isobutyl methyl ketone peroxide: 0.18%–0.24%; Kaolin: 0.55%–0.7%; Ceramic powder: 0.55%~0.7%; Color paste: 0.89%~1.15%; Release agent: 0.34%–0.43%; The formulation of the fiber blend, by weight ratio, is as follows: Glass fiber yarn: 19.56%~21.66%; Carbon fiber yarn: 6.52%~7.22%; Scoring wire: 6.52%~7.22%; Multiaxial fiberglass woven mat or mesh: 24.78%–27.23%; Multiaxial carbon fiber woven felt or mesh: 10.62%–11.67%; Alternatively, the formulation of the fiber blend may be: Fiberglass yarn: 11.41%~12.63% Aramid fiber yarn: 14.67%~16.25% Scoring wire: 6.52%~7.22% Multiaxial fiberglass woven mat or mesh: 14.16%–15.56% Multiaxial aramid woven felt or mesh fabric: 21.24%~23.34%.

12. The high tensile strength composite sleeper according to claim 9, characterized in that, When the resin body is selected as a polyurethane resin mixture, the weight percentage of the resin body is 15% to 20%, and the weight percentage of the fiber mixture is 80% to 85%.

13. The high tensile strength composite sleeper according to claim 12, characterized in that, The formulation of the fiber blend, by weight ratio, is as follows: Glass fiber yarn: 11.54%~12.24%; Basalt fiber yarn: 9.63%–10.2%; Aramid fiber yarn: 9.63%–10.2%; Scoring wire: 7.7%~8.16%; Multiaxial fiberglass woven mat or mesh: 16.6%–17.68%; Multiaxial basalt woven felt or mesh fabric: 12.45%–13.26%; Multiaxial aramid woven felt or mesh fabric: 12.45%–13.26%; The formulation of the polyurethane resin mixture by weight ratio is as follows: Polyols: 6.57%–8.76%; Isocyanates: 8.27%–11.04%; Ceramic powder: 0.16%~0.2%.

14. The high tensile strength composite sleeper according to claim 8, characterized in that, The formulation of the foamed polyurethane resin mixture by weight ratio is as follows: Polyols: 39%–43%; Isocyanates: 39%–43%; Ceramic powder: 1.2%~2.0% Chopped glass fiber yarn: 12.8%–20%.

15. A molding method for preparing a high tensile strength composite sleeper as described in any one of claims 8-14, characterized in that, Includes the following steps: S1. According to the design blueprint requirements, perform a segmentation operation to prepare the pillow body of a certain length; S2. After the rail spike mounting base is formed by die casting or casting, it is machined to form the threaded mounting hole on the rail spike mounting base; or, during the molding process of the rail spike mounting base, the threaded mounting hole is molded at the same time; the pillow body is machined to form foam material injection holes, foam venting holes and mounting through holes that are all connected to the foam cavity on its top wall; S3. Perform cleaning and rinsing operations on the interior of the foaming cavity and the outer wall of the rail spike mounting base; S4. Insert the rail spike mounting base into the foam cavity, ensuring that its threaded mounting hole is aligned with the mounting through hole; S5. Apply release agent to the outer wall of the threaded spike and screw it into the threaded mounting hole; S6. Seal the two open ends of the pillow body; S7. The foamed polyurethane resin mixture is injected into the foaming cavity through the foaming material injection hole until an excess of the foamed polyurethane resin mixture overflows through the foaming vent hole. After a set time, the foamed polyurethane resin mixture is cured and formed. S8. Unscrew the threaded spike from the threaded mounting hole and remove the solidified foamed polyurethane resin mixture that has overflowed from the foaming vent hole.

16. The molding method according to claim 15, characterized in that, Before the foamed polyurethane resin mixture is injected into the foaming cavity, both the pillow body and the rail spike mounting base are preheated, and their temperatures are controlled between 35 and 40°C.

17. The molding method according to claim 15, characterized in that, The diameter of the injection hole of the foaming material is controlled between 25 and 35 mm; the diameter of the venting hole of the foaming material is controlled between 3 and 5 mm.

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