CN115816875A - High-strength polyurethane winding pultrusion pipeline for railway cable passing through rail and preparation method thereof - Google Patents

Abstract

The invention discloses a high-strength polyurethane winding pultrusion pipeline for railway cable cross-track and a preparation method thereof, wherein the cross-track pipeline is a polyurethane winding pultrusion pipeline, and the content of reinforcing fibers accounts for 75-82% of the total weight of the pipeline; the preparation method of the over-rail pipe comprises the steps of adopting a cushion block to assist a core rod and a mould to form a pipeline, arranging a yarn arranging and felt arranging link, distributing and arranging reinforcing fibers according to a cross-sectional view of the over-rail pipe, increasing the using amount of axial reinforcing fibers and improving transverse compressive resistance; and the guide bracket is arranged in the glue injection box, so that a glue injection and impregnation space is ensured, glue injection in multiple directions is adopted, reaction before glue solution solidification is avoided, and the pipeline meets the designed strength requirement. Through professional tests, the maximum stress of the pipeline can reach more than 505Mpa, the design requirements of the strength and the long service life of the over-rail pipe are completely met, and the over-rail pipe has good practical value and application prospect.

Description

High-strength polyurethane winding pultrusion pipeline for railway cable passing through rail and preparation method thereof

Technical Field

The invention relates to a pipeline for railway cable crossing, in particular to a high-strength polyurethane winding pultrusion pipeline for railway cable crossing and a preparation method thereof.

Background

When laying the track of railway, in order to protect the cable conductor, need wrap up the cable conductor together with the pipeline, pre-buried in the track to improve the life of cable conductor. Because the cable is used for laying railway tracks, the cable has certain requirements on the strength of the pipelines, particularly the cable passing pipelines, and the cable passing requirements are met.

At present, two solutions are provided for cable rail crossing, one is to pass through the bridge from the top of the rail by arranging the bridge, the mode avoids the situation that the cable is extruded, but the limiting factors are too many, such as the problems of high cost, requirement on space, unsuitability for mounting the bridge in some environments and the like. Another solution, also a more common solution, is to use a pre-buried rail passing pipe under the rail. In order to protect cables, the traditional track-passing pipeline is made of metal steel pipes, and the traditional track-passing pipeline is replaced by non-metal track-passing pipes in recent years due to the defects of inconvenient installation, difficult rust and corrosion prevention treatment, uneven welding and cable damage and the like. The non-metal pipes commonly used at present comprise PE pipes, PVC pipes, glass fiber reinforced plastic pipes and the like. However, the strength of the PE pipe and the PVC pipe is not high enough, and there is a problem that the cable cannot pass through when the cable is deformed or broken due to reinforcement binding or concrete pouring, or the cable is damaged when the cable collapses during later use. Glass fiber reinforced plastic (SMC) pipes have the advantages of light weight, hardness, stable performance, corrosion resistance and the like, but have the problems of low elastic modulus, easy deformation, poor temperature resistance, easy aging, low shear strength and deformation and fracture when used in a rail crossing process.

Polyurethane, short for polyurethane, is a thermoplastic high molecular compound, has better stability, chemical resistance, rebound resilience and mechanical property than PE pipes and PVC pipes, and is used in the fields of buildings, automobiles, aviation industry, heat preservation, heat insulation and the like. The fiber material is a structural material formed by a fiber material through a textile processing technology, has high strength performance, and can achieve the purpose of improving the strength of the material by combining with a thermoplastic material. One of the existing ways of combining fiber materials and polyurethane is to adopt a winding pultrusion process, namely, the fiber materials are wound on an inner lining pipe or an inner lining layer and then placed in a sealed glue injection box, then two-component polyurethane is injected into the glue box under certain pressure, and a polyurethane winding pultrusion pipeline is formed after high-temperature curing. For example, in a processing method for a high pressure resistant polyurethane winding pultrusion pipeline disclosed in chinese patent document CN114228198a, a pipeline lining material is coated on a core mold to form a tubular lining layer, and fibers are adopted to perform hoop winding on the surface of the lining layer to form a hoop fiber winding layer; adopting fibers to perform cross winding on the surface of the circumferential fiber winding layer to form a cross fiber winding layer; and then entering a gum dipping procedure, injecting the two-component polyurethane material into the pressurized gum dipping procedure under high pressure for permeation gum dipping treatment, and entering a curing procedure for polyurethane curing treatment at high temperature after gum dipping is finished to obtain the corresponding cured high-pressure-resistant polyurethane winding pultrusion pipeline.

However, the current winding pultrusion process has at least the following disadvantages: 1) The fiber material content is insufficient, the axial support is not enough, and the over-orbit requirement cannot be met. The existing polyurethane winding pultrusion pipeline is wound around a central shaft of the pipeline in a fiber material winding mode, the amount of wound fibers is limited, and the axial support of the pipeline is insufficient, so that when the pipeline passes through a rail, the axial support force is insufficient, the pipeline is easy to bend and deform, a cable cannot pass through or be damaged easily, and the use requirement of the pipeline passing through the rail cannot be met. 2) The pipe body has the phenomenon of layering or micro-cracking, and the problem of easy cracking and water leakage exists in the using process. The fiber material is directly wound on the lining pipe or the lining layer and then is subjected to glue injection and solidification, or in order to increase the fiber content, multilayer winding is performed, gaps exist between the fiber material and the lining pipe layer or among layers of the multilayer wound fiber material, the fiber material is not in sufficient contact with polyurethane, the glue dipping is not facilitated, insufficient glue dipping and the phenomena of layering or micro-cracks occur easily, and the problems of cracking and water leakage exist under long-term use; the phenomenon of water storage can occur in railway or other use environments, once water enters the rail passing pipe, the cable can be corroded, the transmission of cable signals can be influenced, the maintenance cost is increased, and drainage and maintenance are inconvenient. 3) And (3) injecting glue by adopting a plurality of glue injection boxes, wherein the resin reacts before curing to cause mold blocking. The existing polyurethane winding pultrusion pipeline adopts a plurality of glue injection boxes during glue injection, so that the two-component polyurethane is easy to react before curing, the mold blocking phenomenon is generated, the smooth production is not facilitated, and the product quality is influenced.

In addition, in the actual production, the reaction activity of each component of polyurethane, the glue injection ratio among the components and the glue injection pressure all affect the performance of the pipeline, so how to produce the polyurethane pipeline suitable for railway cable track crossing is still a problem to be solved urgently.

Disclosure of Invention

Aiming at the problems and achieving the purpose, the invention provides a high-strength polyurethane winding pultrusion pipeline for railway cable track crossing and a preparation method thereof, wherein the content of reinforced fibers accounts for 75-82% of the total weight of the pipeline, so that the strength of the pipeline body is effectively increased; and the cushion block is adopted to assist the core rod and the mould to form the pipeline, the use amount of the axial reinforcing fibers is increased, the glue dipping space is ensured by arranging the guide bracket inside the glue injection box, and the glue injection in multiple directions is adopted, so that the reaction before curing is avoided, and the pipeline meets the designed strength requirement. The specific technical scheme is as follows:

the invention provides a railway cable track-crossing pipeline, which is a polyurethane winding pultrusion pipeline and structurally comprises a main body, a winding reinforced fiber body, a longitudinal reinforced fiber body and a reticular reinforced interlayer, wherein the main body is formed by injection molding of thermosetting polyurethane; and the content of the winding reinforced fiber body, the longitudinal reinforced fiber body and the reticular reinforced interlayer accounts for 75-82% of the total weight of the over-track pipeline.

Preferably, the winding reinforced fiber body is formed by winding reinforced fiber bundles around the axial direction of the track passing pipeline in a multi-layer and bidirectional mode; the reticular reinforced interlayer is distributed in the pipe wall of the pipeline track-passing pipeline at equal intervals along the axial direction of the track-passing pipeline; the longitudinal reinforced fiber bodies are reinforced fiber bundles which are axially and longitudinally distributed in the wall of the rail passing pipe around the rail passing pipe.

Preferably, the reinforcing fiber bundles wound with the reinforcing fiber bodies and the reinforcing fiber bundles of the longitudinal reinforcing fiber bodies are made of basalt fibers, and the reticular reinforcing interlayer is made of polyester felt, has a shape consistent with the cross section of the over-rail pipeline, and has an area smaller than the cross section of the over-rail pipeline.

In the railway cable track-crossing pipeline, the outer wall of the cross section is polygonal, and the outer wall is provided with a water chute sunken towards the inner wall.

Secondly, the invention provides a forming die for the railway cable track-crossing pipeline, which comprises a core rod, a forming die shell and a cushion block; the external dimension of the core rod is the hole pattern and the dimension of the inner hole of the over-track pipeline, the core rod penetrates through the forming formwork and is positioned at the central axis position of the forming formwork cavity through the cushion block; the section of the inner cavity of the forming mould shell is polygonal, and the wall of the inner cavity is provided with a convex water tank forming strip.

Preferably, the core rod and the forming mold shell are both Cr ₁₂ The core rod is positioned on the central axis of the forming die shell cavity; the cushion blocks are made of No. 45 steel materials, are distributed on the upper side and the lower side of the two traction clamps at the two ends of the forming formwork, and have the thickness consistent with the wall thickness of the railway cable track-passing pipeline.

The invention further provides a glue injection box for injection molding of the railway cable track-crossing pipeline, which comprises a glue injection box body, wherein a glue injection cavity communicated with a molding mould shell cavity is arranged in the glue injection box body, a plurality of guide supports are arranged in the glue injection cavity, reinforcing fiber bundles are separated to form infiltration spaces, and a plurality of glue impregnation holes are formed in the supports.

Preferably, a plurality of glue injection holes are formed in the glue injection box body; the glue injection holes are distributed on the side wall of the glue injection box body and are positioned between the two guide supports or between the guide supports and the side wall of the glue injection box body.

In addition, the invention also provides a preparation method of the railway cable track-crossing pipeline, which is prepared by adopting the forming mold and the glue injection box and specifically comprises the following steps:

1) Assembling a mold: the core rod passes through a cavity of the over-rail pipeline forming formwork, and the position of the core rod is adjusted at the central position of the cavity of the forming formwork through a cushion block;

2) Preparing glue solution: preparing two-component thermosetting polyurethane resin, including resin A and resin B; the component of the resin A comprises carbamate, ether, ester, allophanate and internal mold release agent; the resin B comprises isocyanate; and the mass ratio of the resin A to the resin B is 105 to 108;

3) Adjusting the core rod: adjusting the fixed end of the core rod to fix the relative position of the fixed end and the pipeline forming formwork;

4) Arranging yarn and cloth felt: cutting the polyester felt into a proper size according to the cross-sectional view of the over-track pipeline, and positioning the polyester felt to a preset position through a felt guide; then combining the cross-sectional view of the rail pipeline to distribute and arrange the reinforced fiber bundles;

5) Fiber threading: marking a plurality of areas on the yarn threading plate according to the design, respectively threading basalt fibers into holes corresponding to the yarn collecting plate according to the designed quantity, and leading out after separated guiding by a guide bracket in the glue injection box body;

6) Extruding, drawing and winding: heating the forming die, controlling the temperature of the die inlet, the middle and the die outlet of the forming die, and simultaneously injecting the prepared resin A glue solution and resin B glue solution into corresponding glue barrels; after the temperature of the forming die is stable, opening a pultrusion device, a winding device and a glue injection machine at the same time, injecting glue and impregnating glue according to the set glue injection pressure and proportion, performing pultrusion according to the set traction speed, and adjusting the number of layers of the wound reinforcing fibers according to the traction speed; and obtaining the high-strength railway cable track-passing pipeline after glue injection, gum dipping and curing.

In step 2), the mass ratio of the carbamate, the ether, the ester, the urea, the allophanate and the internal mold release agent in the resin a is 50; the resin B comprises isocyanate which is diphenylmethane diisocyanate; in step 6), the temperature of the forming die is raised, and the temperatures of a die inlet, a middle part and a die outlet of the forming die are respectively controlled to be 100-120 ℃, 130-150 ℃ and 150-170 ℃; the temperature of the glue injection is 20-25 ℃, and the pressure is 1.5-2.5 Mpa; the traction speed is 0.35-0.5 m per minute; the number of layers of the winding reinforcing fiber is 1 layer in the forward and reverse directions.

The invention has the beneficial effects that:

1) The invention adopts the polyurethane winding pultrusion pipeline as the railway cable track-crossing pipeline for the first time, the content of the reinforced fiber of the pipeline accounts for 75 to 82 percent of the total weight of the pipeline, and the strength requirement of the polyurethane pipe as the railway cable track-crossing pipeline is effectively ensured; and through process improvement, the axial fiber support is increased, the polyurethane component gum dipping is improved, the finishing stress capability of the pipe body is ensured, and the pipe body is ensured to adapt to the buried track passing environment and has long service life.

2) The invention adopts the cushion block to assist the core rod and the mould to form the pipeline, the core rod is inserted into the mould cavity, the cushion block is padded between the core rod and the mould to form the pipe wall space, and the polyester felt is used for arranging the reinforcing fiber, thereby avoiding the use of an inner lining pipe or an inner lining layer, ensuring that the integrity of the pipe body is higher, solving the problem of layered cracks and enhancing the strength and the use performance of the pipe body.

3) According to the invention, by arranging the polyester felt, the reinforcing fibers can be randomly arranged according to the designed strength and position, the axial fiber arrangement amount of the pipe body is increased, the transverse strength of the pipe body is increased, the pressure resistance capability of the pipe body is improved, and the use safety of the cable in the over-rail pipe is ensured.

4) The guide bracket is arranged inside the glue injection box, so that the reinforced fibers form a space, and the polyurethane is convenient to quickly soak; and adopt a plurality of directions injecting glue, avoid using resin to react and take place stifled mould phenomenon before a plurality of injecting glue box solidification, improve production efficiency, guarantee product quality.

5) The product of the over-track pipeline has low specific gravity and is convenient to transport and install; the paint is impact-resistant and corrosion-resistant, can resist some inevitable collision friction in the production process, and can be used in some special environments such as acid-base environment, coastal environment and the like; and the insulating property is good, and the cable can be used as a railway cable track-crossing pipeline, so that the damage caused by electric conduction can be avoided.

6) Through professional tests, the maximum stress of the pipeline can reach more than 505Mpa, the compressive resistance is 2 times that of cast iron and 6-8 times that of a common SMC material, and the design requirement of long service life of the cross-rail pipe can be met. The cross-rail pipe can realize segmented connection by designing the water guide groove and the connecting elbow, is connected by the 45-degree elbow and then led out of the ground to replace a hand hole well, is favorable for branch cable switching, installation and drainage, and has good practical value and application prospect.

Drawings

FIG. 1 is a schematic structural view of a high-strength polyurethane winding pultrusion pipeline for railway cable crossing;

FIG. 2 is a schematic view of the internal structure of the cross-track pipeline of the present invention;

FIG. 3 is a schematic view of the assembly of the over-track pipe core rod, the spacer block and the forming mold shell;

FIG. 4 is a schematic structural view of the glue injection box of the present invention;

FIG. 5 is a stress cloud of the cross section of the over-the-track pipeline of the present invention;

FIG. 6 is a cross-sectional minimum stress cloud for a cross-section of a cross-track pipeline according to the present invention;

FIG. 7 is a cloud of maximum stress across the cross-section of the inventive cross-track pipeline;

FIG. 8 is a strain cloud of the cross section of the cross-track pipeline of the present invention;

FIG. 9 is a cross-sectional deformation cloud of the over-track pipeline of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and the accompanying drawings.

Example 1

The embodiment is to prepare a high-strength polyurethane winding pultrusion pipeline for railway cable cross-track, the structure of the cross-track pipeline is shown in figures 1 and 2, the structure of the cross-track pipeline comprises a main body formed by injection molding of thermosetting polyurethane, a winding reinforced fiber body, a longitudinal reinforced fiber body and a reticular reinforced interlayer which are distributed in the main body; and the content of the winding reinforced fiber body, the longitudinal reinforced fiber body and the reticular reinforced interlayer accounts for 75-82% of the total weight of the over-track pipeline. The winding reinforced fiber body is formed by winding reinforced fiber bundles around the axial direction of the over-rail pipeline in a multi-layer and bidirectional mode; the reticular reinforced interlayer is distributed in the pipe wall of the pipeline cross-rail pipeline at equal intervals along the axial direction of the cross-rail pipeline; the longitudinal reinforced fiber body is formed by longitudinally distributing reinforced fiber bundles in the wall of the rail-passing pipe around the rail-passing pipe in the axial direction. The reinforced fiber bundles wound with the reinforced fiber bodies and the reinforced fiber bundles of the longitudinal reinforced fiber bodies are both made of basalt fibers, the reticular reinforced interlayer is made of polyester felt, the shape of the reticular reinforced interlayer is consistent with the cross section of the over-rail pipeline, and the area of the reticular reinforced interlayer is smaller than the cross section area of the over-rail pipeline. And the outer wall of the cross section of the cross-rail pipeline is polygonal, and a water guide groove which is sunken towards the inner wall of the cross-rail pipeline is arranged on the outer wall of the cross-rail pipeline. The preparation method comprises the following steps:

1) Preparing a forming die: designing and preparing a core rod according to the hole pattern and the size requirement of an inner hole of the over-track pipeline; root of herbaceous plantPreparing a forming die according to the modeling and size design of the outer wall of the through-rail pipeline; and designing and preparing a cushion block for later use. Wherein the core rod is made of Cr and the over-orbit pipeline forming die ₁₂ The core rod is positioned on the central axis of the forming mould shell cavity; the cushion blocks are made of No. 45 steel and are distributed on the upper side and the lower side of two traction clamps at the two ends of the forming formwork, and the section thickness of the cushion blocks is consistent with the shape and the wall thickness of the section of the over-track pipeline so as to ensure that the pipeline is not crushed, as shown in figure 3. The injection molding glue injection box comprises a glue injection box body, wherein a glue injection cavity communicated with a molding mould shell cavity is arranged in the glue injection box body, a plurality of guide brackets are arranged in the glue injection cavity, reinforcing fiber bundles are separated to form an infiltration space, a plurality of glue soaking holes are formed in the brackets, and a plurality of glue injection holes are formed in the glue injection box body; the glue injection holes are distributed on the side wall of the glue injection box body and are located between the two guide supports or between the guide supports and the side wall of the glue injection box body, as shown in fig. 4.

2) Preparing glue solution: preparing a resin A glue solution according to the mass ratio of carbamate to ether to ester to urea to allophanate to internal mold release agent of 50.

3) Adjusting the core rod: inserting the prepared core rod into a cavity of a forming die, adjusting and positioning the position of the core rod at the central position of the cavity of the forming die through a cushion block, and fixing the relative position of the core rod and the pipeline forming die through a fixed end of the core rod, as shown in fig. 2;

4) Arranging yarn and cloth felt: cutting the polyester felt into a proper size according to the cross-sectional view of the cross-track pipeline, and positioning the polyester felt to a proper position through a felt guide; and the reinforced fibers are distributed and arranged in combination with the cross-sectional view of the rail pipeline. The principle is that the cross-sectional areas of all parts of the cross-track pipeline are uniformly distributed, and reinforcing fibers are reasonably arranged in the axial direction to enhance the compression resistance of the pipe body.

5) Fiber threading: marking a plurality of areas on the yarn threading plate according to the design, and respectively threading the basalt fibers into the holes of the corresponding yarn collecting plate according to the designed quantity for later use.

6) Extruding, drawing and winding: heating the forming die, controlling the temperature of the die inlet of the forming die to be 130 ℃, the temperature of the middle of the forming die to be 140 ℃ and the temperature of the die outlet of the forming die to be 160 ℃, and simultaneously injecting the prepared resin A glue solution and resin B glue solution into corresponding glue barrels; and after the temperature of the forming die is stable, opening the pultrusion equipment, the winding equipment and the glue injection machine, injecting glue and impregnating glue according to the set glue injection pressure and proportion, performing pultrusion according to the set traction speed, and adjusting the number of layers of the basalt fiber to be wound according to the traction speed. The specific operation is as follows:

a. the panel of the winding machine is opened to set the winding speed to weave the glass fiber to be wound on the longitudinal glass fiber

b. Opening the traction equipment, and starting the oil cylinder to work;

c. overlapping a winding encoder on the front-end glass fiber, and starting an automatic winding function;

d. connecting the glue injection pipe to the upper surface of a glue injection opening of the mold and starting an automatic glue injection function;

e. and starting the tractor to pull the section bar, and starting automatic winding and glue injection work when the winding machine encoder and the glue injection machine probe receive an operation instruction.

In the embodiment, the content of the basalt fiber reinforced fibers is controlled to be 75-82%, preferably 80-82%, and most preferably 82% of the total weight of the pipeline; and (3) winding and pultrusion the polyurethane obtained after glue injection, gum dipping and curing to obtain the high-strength railway cable track-crossing pipeline.

Example 2 the reinforcing fiber content was 73% by weight of the total weight of the pipe

This example also prepared a high strength polyurethane wound pultruded pipe for railway cable transition, the outer profile and inner diameter dimensions of the transition pipe structure were the same as those of example 1, and the reinforcing fiber content was 73% of the total weight of the pipe. The other operations were the same as in example 1 to obtain a polyurethane-wrapped pultruded pipe as comparative product 1.

Example 3 the reinforcing fiber content was 85% by weight of the total weight of the pipe

This example also prepared a high strength polyurethane wound pultruded pipe for railway cable transition, the outer profile and inner diameter dimensions of the transition pipe structure were in accordance with example 1, and the reinforcing fiber content was 85% of the total weight of the pipe. The other operations were the same as in example 1 to obtain a polyurethane-wrapped pultruded pipe as comparative product 2.

Example 4 No spacer

In this embodiment, a high-strength polyurethane winding pultrusion pipeline for railway cable cross-track is also prepared, the dimensions of the outer profile surface and the inner diameter of the cross-track pipeline structure are the same as those of embodiment 1, and the content of the reinforcing fiber accounts for 82% of the total weight of the pipeline, but the step of adjusting the core rod of the preparation method does not adopt a cushion block, but directly wraps the basalt fiber reinforcing fiber on the core rod to form an inner liner layer, and the inner liner layer is subjected to gum dipping. Otherwise the same procedure as in example 1 was followed to obtain a polyurethane-wound pultruded pipe as comparative product 3.

Example 5 absence of axial reinforcing fibers

In this embodiment, a high-strength polyurethane winding pultrusion pipeline for railway cable cross-track is also prepared, the dimensions of the outer profile and the inner diameter of the cross-track pipeline structure are the same as those of embodiment 1, the content of the reinforced fibers also accounts for 82% of the total weight of the pipeline, but the step of arranging the yarn and cloth felts is not performed, polyester felts and axial reinforced fibers are not adopted, basalt fiber reinforced fibers are directly wrapped on a core rod to form an inner liner layer, the step of extruding, pulling and winding is directly performed, and other operations are the same as those of embodiment 1, so that the polyurethane winding pultrusion pipeline is obtained and serves as a comparative product 4.

Embodiment 6 the glue injection box is not provided with a guide bracket

The dimensions of the outer profile and the inner diameter of the high-strength polyurethane winding pultrusion pipeline for railway cable crossing prepared in the embodiment are the same as those of the embodiment 1, the content of the reinforced fibers accounts for 82% of the total weight of the pipeline, but when the pipeline is extruded, pulled and wound, the rubber injection box is not provided with a guide bracket, other operations are the same as those of the embodiment 1, and the polyurethane winding pultrusion pipeline is obtained and serves as a comparative product 5.

Effect example 1

This example was conducted to examine the properties of each of the polyurethane-wrapped pultruded pipelines prepared in examples 1-6, and the examination items included tensile strength, post-immersion tensile strength, flexural strength, babbitt hardness, hoop stiffness, drop hammer impact, hot edge profile, and oxygen index. Specific results are shown in table 1.

TABLE 1 Performance test results for each polyurethane-wound pultruded pipeline

It can be seen from the above table that the three cross-rail pipes of the examples have good compression resistance which is 2 times of that of cast iron and 6-8 times of that of common SMC materials, and compared with examples 1 and 2 and 3, when the fiber content is less than 75% and more than 82%, the tensile strength, tensile strength after soaking, bending strength, ring stiffness and hot edge shape all meet the requirements of the cross-rail pipes, however, when the drop weight is heavy hit (the drop weight is 1.5 t), cracks and cracks exist, and the construction environment and application environment facing the cross-rail pipes are hard to avoid the impact effect, so that the cross-rail pipes are not suitable for being used as the cross-rail pipes. The reason for this analysis may be that the pipe body has insufficient supporting force when the fiber content is less than 75%, and the pipe body has relatively reduced polyurethane component when the fiber content is more than 82%, making it difficult to form a proper crosslinking system, and the pipe wall becomes brittle and cracks appear in the face of impact. And, the fiber content higher than 82% is that its oxygen index also improves correspondingly, has flammable risk, is more unsuitable to be used as the pipe of crossing the rail.

Comparing example 1 with examples 4 and 6, it can be seen that the pipe body is obviously layered without adopting a cushion block and without a guide bracket, which means that the support of the cushion block is illustrated, the winding fiber is moved inwards to be well wrapped in polyurethane, and no inner liner layer exists (or the inner liner layer and the pipe body are integrally formed), so that the pipe body has good integrity; the guide support enables the reinforced fibers to be dispersed, has a good infiltration space, can be infiltrated fully, enables the reinforced fibers and the polyurethane to be compatible well, enables all the components to be combined tightly, and improves the strength of the pipe body.

Further, comparing example 1 and example 5, it can be seen that the axial fibers have an influence on each item of strength of the entire pipe, particularly tensile strength after immersion in water, bending strength, ring stiffness and heat distortion, in addition to the oxygen index. The reason is that the circumferential strength and the bending strength of the pipeline are enhanced by the axial fibers and the polyester felt, and the shearing force born by the bending is enhanced, which is obvious; the axial fibers penetrate through the polyester felt, so that the restraint effect of the reinforcing fiber bundles in the pipeline is enhanced to a certain extent, and the fibers are in the original positions or the deformation degree of the fibers is reduced when the pipeline is soaked in water and subjected to the action of heat, so that the pipeline is adapted to the environment of the over-track pipeline.

Effect example 2

The stress strength of the over-the-rail pipe with the reinforcing fiber content of 82% of the total weight of the pipe as described in example 1 was analyzed by using stress analysis software ansys finite element analysis, abaqus or fluent, etc. As a result, as shown in fig. 4 to 9, under the action of equivalent (Von-Mi Saisi, von Mises Stress) (fig. 5), the hazardous area in the pipeline is less, only the upper and lower sides, especially the upper side, of the pipeline exist, which reflects the environmental test faced by the over-track pipeline on the side, and the pipeline strength of the invention can be adapted to the environment; the minimum principal stress and the maximum principal stress (figures 6 and 7) can show that the pipe body has good effect of resisting external force and deformation; the equivalent elastic strain of fig. 8 and the total deformation analysis of fig. 9 also demonstrate good resistance to deformation and deformation recovery.

In general, the invention adopts the polyurethane winding pultrusion pipeline as the railway cable track-crossing pipeline for the first time, the content of the reinforced fiber of the pipeline accounts for 75-82% of the total weight of the pipeline, and the strength requirement of the polyurethane pipe as the railway cable track-crossing pipeline is effectively ensured; and through process improvement, the axial fiber support is increased, the dipping of the polyurethane component is improved, the finishing stress capability of the pipe body is ensured, and the pipe body is ensured to be suitable for the ground-buried over-rail environment and to have long service life.

The cushion block is adopted to assist the core rod and the mould forming pipeline, the core rod is inserted into the mould cavity, the cushion block is filled between the core rod and the mould to form a pipe wall space, and the polyester felt is used for arranging the reinforcing fiber, so that the use of an inner lining pipe or an inner lining layer is avoided, the integrity of the pipe body is higher, the problem of layered cracks is solved, and the strength and the service performance of the pipe body are enhanced. Through setting up the polyester felt, the realization can arrange reinforcing fiber according to the intensity and the position of design wantonly, increases body axial fibre and arranges the volume, increases body transverse strength, promotes its resistance to pressure's ability, guarantees the safe in utilization of crossing cable conductor in the rail pipe. The guide bracket is arranged in the glue injection box, so that the reinforced fibers form a space, and the polyurethane is convenient to quickly soak; and adopt the injecting glue of a plurality of directions, the resin takes place the reaction and takes place stifled mould phenomenon before using a plurality of injecting glue boxes solidification, improves production efficiency, guarantees product quality.

In addition, the over-rail pipeline product has low specific gravity and is convenient to transport and install; the paint is impact-resistant and corrosion-resistant, can resist some inevitable collision friction in the production process, and can be used in some special environments such as acid-base environment, coastal environment and the like; and the insulating property is good, and the cable can be used as a railway cable track-crossing pipeline, so that the damage caused by electric conduction can be avoided. Through professional tests, the compressive resistance is 2 times that of cast iron and 6-8 times that of a common SMC material, and the long-life design requirement of the rail-passing pipe can be met. The track passing pipe can realize segmented connection by designing the water guide groove and the connecting elbow, is connected by the 45-degree elbow and then led out of the ground instead of a hand hole well, is favorable for branch cable switching, installation and drainage, and has good practical value and application prospect.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. In addition, it should be understood that, although the present specification describes embodiments, one embodiment is not included, and the description is only for clarity, and those skilled in the art should be able to take the description as a whole, and the embodiments may be appropriately combined to form other embodiments understood by those skilled in the art.

Claims (10)

1. A railway cable cross-track pipeline is characterized in that: the over-track pipeline is a polyurethane winding pultrusion pipeline and structurally comprises a main body, a winding reinforced fiber body, a longitudinal reinforced fiber body and a reticular reinforced interlayer, wherein the main body is formed by injection molding of thermosetting polyurethane; and the content of the winding reinforced fiber body, the longitudinal reinforced fiber body and the reticular reinforced interlayer accounts for 75-82% of the total weight of the over-track pipeline.

2. The railway cable transition duct of claim 1, wherein: the winding reinforced fiber body is formed by winding reinforced fiber bundles around the axial direction of the track passing pipeline in a multi-layer and bidirectional way; the reticular reinforced interlayer is distributed in the pipe wall of the pipeline cross-rail pipeline at equal intervals along the axial direction of the cross-rail pipeline; the longitudinal reinforced fiber bodies are reinforced fiber bundles which are axially and longitudinally distributed in the wall of the rail passing pipe around the rail passing pipe.

3. The railway cable transition duct of claim 2, wherein: the reinforced fiber bundles wound with the reinforced fiber bodies and the reinforced fiber bundles of the longitudinal reinforced fiber bodies are both made of basalt fibers, the reticular reinforced interlayer is made of polyester felt, the shape of the reticular reinforced interlayer is consistent with the cross section of the cross-rail pipeline, and the area of the reticular reinforced interlayer is smaller than the cross section area of the cross-rail pipeline.

4. The railway cable transition duct of claim 1, wherein: the outer wall of the section of the water guide groove is polygonal, and a water guide groove which is sunken towards the inner wall of the water guide groove is arranged on the outer wall.

5. A forming die for railway cable track-passing pipe according to any one of claims 1 to 4, comprising a core rod and a forming die shell, wherein: also comprises a cushion block; the shape and size of the core rod are the hole pattern and size of the inner hole of the over-track pipeline, the core rod penetrates through the forming formwork and is positioned at the central axis position of the forming formwork cavity through the cushion block; the section of an inner cavity of the forming mould shell is polygonal, and a convex water tank forming strip is arranged on the wall of the inner cavity.

6. The railway cable track pipe forming die of claim 5, wherein: the core rod and the forming mould shell are both Cr ₁₂ Chrome-plated material after MoV heat treatmentMaterial manufacturing, wherein a core rod is positioned on a central axis of a forming mould shell cavity; the cushion blocks are made of No. 45 steel materials, are distributed on the upper side and the lower side of the two traction clamps at the two ends of the forming formwork, and have the thickness consistent with the wall thickness of the railway cable track-passing pipeline.

7. A glue injection box of a railway cable track-passing pipeline according to any one of claims 1 to 4, which comprises a glue injection box body, wherein a glue injection cavity communicated with a forming formwork cavity is arranged in the glue injection box body, and the glue injection box is characterized in that: the glue injection cavity is internally provided with a plurality of guide supports which separate the reinforced fiber bundles to form infiltration spaces, and the supports are provided with a plurality of glue impregnation holes.

8. The glue injection box for railway cable track-crossing pipes according to claim 7, characterized in that: the glue injection box body is provided with a plurality of glue injection holes; the glue injection holes are distributed on the side wall of the glue injection box body and are positioned between the two guide supports or between the guide supports and the side wall of the glue injection box body.

9. A method of manufacturing a railway cable-passing conduit according to any one of claims 1 to 4, wherein: the preparation method by adopting the forming die of claim 5 or 6 and the glue injection box of claim 7 or 8 comprises the following steps:

1) Assembling a mold: the core rod penetrates through a cavity of the over-track pipeline forming formwork, and the position of the core rod is adjusted at the central position of the cavity of the forming formwork through a cushion block;

2) Preparing glue solution: preparing two-component thermosetting polyurethane resin, including resin A and resin B; the component of the resin A comprises carbamate, ether, ester, allophanate and internal mold release agent; the resin B comprises isocyanate; the mass ratio of the resin A to the resin B is 105-108;

3) Adjusting the core rod: adjusting the fixed end of the mandrel to fix the relative position of the fixed end and the pipeline forming formwork;

4) Arranging yarn and laying felt: cutting the polyester felt into a proper size according to the cross-sectional view of the over-track pipeline, and positioning the polyester felt to a preset position through a felt guide; then, combining the cross-sectional view of the rail pipeline to carry out distribution arrangement on the reinforced fiber bundles;

5) Fiber threading: marking a plurality of areas on the yarn threading plate according to the design, respectively threading basalt fibers into holes corresponding to the yarn collecting plate according to the designed quantity, and leading out after separated guiding by a guide bracket in the glue injection box body;

6) Extruding, drawing and winding: heating the forming die, controlling the temperature of the die inlet, the middle and the die outlet of the forming die, and simultaneously injecting the prepared resin A glue solution and resin B glue solution into corresponding glue barrels; after the temperature of the forming die is stable, opening a pultrusion device, a winding device and a glue injection machine at the same time, injecting glue and impregnating glue according to the set glue injection pressure and proportion, performing pultrusion according to the set traction speed, and adjusting the number of layers of the wound reinforcing fibers according to the traction speed; and obtaining the high-strength railway cable track-passing pipeline after glue injection, gum dipping and curing.

10. The method of claim 9, wherein the step of preparing the railway cable passage conduit comprises:

in step 2), the mass ratio of carbamate, ether, ester, urea, allophanate and internal mold release agent in the resin a is 50; the resin B comprises isocyanate which is diphenylmethane diisocyanate;

in step 6), the temperature of the forming die is increased, and the temperatures of a die inlet, a middle part and a die outlet of the forming die are respectively controlled to be 100-120 ℃, 130-150 ℃ and 150-170 ℃; the temperature of the glue injection is 20-25 ℃, and the pressure is 1.5-2.5 Mpa; the traction speed is 0.35-0.5 m/min; the number of layers of the winding reinforcing fiber is 1 layer in the forward and reverse directions.

Images