A progressive expansion rail system and method for replacing type iii slab of ballastless track

Abstract

The application is specifically a progressive rail expansion system and method for replacing type III slab of ballastless track, which comprises two sets of master-slave rail expansion devices, adopts a hollow skeleton in the shape of Chinese character Wang, three-stage electric push rods, displacement sensors, laser range finders, infrared thermometers and PLC control. The middle part of the linear shape is large and the two ends are small through the progressive rail expansion algorithm, three-stage progressive rail expansion, stable voltage self-locking, and double-machine synchronization, over-travel, strain, rail temperature and communication interlocking protection. After the slab is replaced, the device is reset in stages and the data is archived. The application has the following advantages: the progressive rail expansion displacement distribution algorithm is used to generate the "middle large and two ends small" rail expansion curve with the maximum displacement in the center of the slab and the attenuation to zero towards the two ends, and to distribute the target stroke of each stage of push rod; the double-machine synchronization deviation determination algorithm is used to realize millimeter-level synchronous correction and over-limit interlocking; and the double-machine cooperative progressive rail expansion timing and the matched multi-stage electric push rod are used to realize the standardized rail expansion operation with low stress, high precision and high safety in the replacement of type III slab of ballastless track.

Description

Technical Field

[0001] This invention relates to the field of high-speed railway ballastless track maintenance equipment technology, specifically a ballastless track type III slab replacement progressive track expansion system and method. Background Technology

[0002] High-speed railway ballastless track type III slabs are prone to defects such as slab cracking, mortar layer peeling, and structural settlement during long-term service, requiring regular replacement and maintenance. Rail widening operations typically involve placing rail widening equipment at both ends of the track slab to be replaced. After loosening the fasteners in the work section, hydraulic equipment is used to laterally push the rail outwards to widen the gauge and create space for slab replacement. After the replacement is completed, the rail is retracted back to its original position. In traditional type III slab replacement construction, rail widening operations mainly rely on manual operation of hydraulic equipment, which has many technical drawbacks.

[0003] Firstly, the main method is to use a single machine for large-displacement jacking operations, which lacks a mathematical model to automatically allocate the shifting stroke. This makes it difficult to form a gradually expanding rail profile with a larger diameter in the middle and smaller diameter at both ends. As a result, the stress concentration in the track structure is severe, which can easily cause secondary defects such as rail damage, cracking of track slab edges and corners, and crushing of the base mortar.

[0004] Secondly, there is no hardware synchronization communication interface between multiple track-expanding devices. They rely on manual coordination and operation, and there is no quantitative synchronization deviation judgment algorithm. The displacement control error is large, which makes it difficult to meet the millimeter-level construction accuracy requirements of high-speed rail and easily leads to track alignment exceeding the standard.

[0005] Third, the lack of an environmental temperature control mechanism during construction and the absence of a joint safety assessment model for displacement and strain, coupled with the significantly increased brittleness of rails under extremely low temperatures, make blindly carrying out rail expansion operations prone to rail head cracking and fatigue damage to the track structure.

[0006] Fourth, the lack of a maximum travel limit for rail expansion, relying entirely on manual judgment of the shifting amount, poses a significant safety hazard of excessive rail shifting and stress exceeding limits.

[0007] Fifth, equipment alignment, track expansion adjustment, and attitude fixation all rely on manual operation, without an automatic collaborative interlocking mechanism. The time for graded track expansion and pressure stabilization depends on experience and is set manually. The level of automation and intelligence is low, resulting in low construction efficiency, high labor costs, and the inability to standardize and control construction quality.

[0008] Currently available rail widening equipment is mostly a single-machine, general-purpose mechanical widening structure, lacking a dual-machine collaborative, graded, and progressive widening scheme adapted for Type III rail replacement. It also lacks built-in automated algorithm models for displacement distribution, synchronization deviation, safety boundaries, and voltage stabilization delay, making it unable to automatically generate rail shifting alignments that are larger in the middle and smaller at both ends. Furthermore, it lacks rail temperature safety interlocks and does not have maximum travel limits for rail widening. Existing equipment cannot achieve standardized rail widening operations with low stress, high precision, and high safety. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a progressive track expansion system and method for replacing Type III ballastless track slabs. This system generates a "large in the middle and small at both ends" track expansion curve by using a progressive track expansion displacement allocation algorithm, which maximizes the expansion at the center of the slab and decreases to zero at both ends. It also allocates the target stroke of each stage of push rods. A dual-machine synchronous deviation judgment algorithm is used to achieve millimeter-level synchronous correction and over-limit interlocking. Furthermore, relying on the dual-machine collaborative progressive track expansion sequence and its matched multi-stage electric push rods, the system progressively expands the track step by step from pre-expansion to mid-expansion to final expansion, and then cuts off power and stabilizes the voltage to lock the track upon reaching the final position. This enables a standardized track expansion operation with low stress, high precision, and high safety in the replacement of Type III ballastless track slabs.

[0010] To achieve the above objectives, a gradual track widening system for replacing type III slab of ballastless track is designed, which includes two identical track widening devices and a PLC control module integrated on the track widening devices; the two track widening devices are respectively arranged at both ends of the track slab to be replaced along the line direction, with an operation space for the track slab to be reserved between each other. Each track widening device comprises: a king-shaped hollow spider-type framework, which serves as a bearing base body; a walking roller assembly and a walking drive motor, both of which are arranged at the bottom of the king-shaped hollow spider-type framework and are in transmission connection with each other; six multi-stage electric push rods, which are symmetrically arranged on the king-shaped hollow spider-type framework left and right respectively, and are divided into a front group, a middle group and a rear group along the longitudinal direction of the line. The front group is a first-stage pre-widening push rod, the middle group is a second-stage intermediate-widening push rod, the rear group is a third-stage final-widening push rod, and the maximum designed strokes of the front, middle and rear groups of push rods increase step by step; a plurality of displacement sensors, which are respectively built in the six multi-stage electric push rods and measure the lateral displacement of the multi-stage electric push rods; a laser range finder, which is arranged on the king-shaped hollow spider-type framework and measures the lateral displacement of the steel rail; the displacement sensors built in the push rods and the laser range finder form double comparison of the operation stroke of the track widening device; the end of the third-stage final-widening push rod is further provided with a mechanical stop, which forms dual limit of software and machinery with the built-in displacement sensor; the king-shaped hollow spider-type framework is further provided with a steel rail infrared thermometer; the PLC control module is integrated on the front side of the king-shaped hollow spider-type framework, and is internally provided with an industrial Ethernet communication module, a distributed clock synchronization module and a safety IO hard-wired interlock interface; the two track widening devices are respectively configured as a master unit and a slave unit, the PLC control module of the master track widening device is configured with a gradual track widening displacement distribution algorithm, the algorithm generates a track widening displacement curve with a large middle and small two ends, where the maximum single-side lateral target shifting amount of the steel rail at the center of slab replacement is maximum, and the amount gradually attenuates to zero towards the positions of the track widening devices at both ends. The PLC control module of the master unit obtains the target output stroke of each push rod of the two track widening devices according to the curve, and issues time sequence and stroke instructions to the slave unit through the industrial Ethernet communication module; the distributed clock synchronization module is used for controlling the sampling and output instruction time sequences of the two track widening devices to be consistent. The safety IO hard-wired interlock interface is arranged in parallel with the industrial Ethernet communication module, and is respectively connected with the PLC control modules of the two track widening devices and the push rod power circuits through hard wires; the PLC control module controls the first-stage pre-widening push rods, the second-stage intermediate-widening push rods and the third-stage final-widening push rods of the two track widening devices to progress step by step according to the dual-machine cooperative gradual track widening time sequence, and controls power-off voltage-stabilizing self-locking after each stage of push rods reaches a preset stroke.

[0011] Preferably, the present invention further comprises: the I-shaped hollow spider-type skeleton comprises an extension bracket for carrying the multi-stage electric push rod, the extension bracket is of a hollow structure and completely encloses the multi-stage electric push rod; the multi-stage electric push rod comprises a horizontally arranged push rod body and a bottom plate vertically arranged at the tail end of the push rod, and the peripheral edge of the bottom plate is fixedly connected with the inner side wall of the hollow structure of the extension bracket; support lugs are vertically arranged inside the hollow structure of the extension bracket, the support lugs are connected with the side of the push rod body away from the bottom plate, through holes with the same shape as the support lugs are formed in the bottom plate of the multi-stage electric push rod, the support lugs and the bottom plate are arranged in a left-right staggered manner and are aligned through the through holes; on the lateral projection plane, the support lugs and the bottom plate form a mutually matched envelope, and the support lugs and the bottom plate jointly form up-down and left-right staggered multi-stage support for the multi-stage electric push rod.

[0012] Preferably, the present invention further comprises: a rail infrared thermometer, arranged between the first-stage pre-expansion push rod and the second-stage intermediate-expansion push rod on the I-shaped hollow spider-type skeleton; a laser range finder, arranged between the second-stage intermediate-expansion push rod and the third-stage final-expansion push rod on the I-shaped hollow spider-type skeleton.

[0013] Preferably, the present invention further comprises: the PLC control module is further provided with rail temperature safety interlock, automatic traveling alignment, dual over-travel protection, multi-stage power-off self-locking, fault-communication global interlock and external expansion interface; the rail temperature safety interlock presets a construction threshold of -20°C, the automatic traveling alignment controls the traveling drive motor according to the station distance input from the man-machine interface and automatically brakes and locks when reaching the preset position, the dual over-travel protection cuts off all power output of the push rods when any one of the two signals from the built-in displacement sensor inside the push rod and the laser range finder detects that the rail expansion displacement of a single side rail reaches 750mm, and the mechanical stop limits the push rod from extending further, the multi-stage power-off self-locking automatically cuts off power and locks when each stage of push rod reaches the preset stroke or triggers the 750mm over-travel limit, and one unit will synchronously self-lock when the other self-locks, the fault-communication global interlock triggers two sets of rail expansion devices to synchronously lock the rail pushing action through the dual channels of industrial Ethernet and safety IO hard wiring when displacement deviation exceeds the limit, over-travel, low temperature alarm or network communication interruption occurs, and the external expansion interface is used for accessing the composite vertical support sliding unit and the rail strain sensor.

[0014] This invention also provides a method for progressive rail expansion for replacing CRTS III type slabs of ballastless track, using the aforementioned progressive rail expansion system for replacing CRTS III type slabs of ballastless track, including the following steps: S1, Construction preparation and communication self-test: The two sets of rail expansion devices are respectively transported to both ends of the CRTS III type slab to be replaced along the track direction, with a reserved space for track slab replacement work between the two sets of rail expansion devices; after the equipment is powered on, a master-slave communication link is established through industrial Ethernet, the distributed clock synchronization module completes hardware time synchronization, confirms that the safety IO hard-wired interlocking line is connected properly, and completes the self-test of the dual-machine collaborative link; S2, Rail temperature safety interlock judgment: The infrared thermometer collects the surface temperature of the rails on both sides in real time, and when the rail temperature is below -20°C... When the rail temperature reaches -20℃, both sets of rail-expanding devices simultaneously lock all rail-expanding actions and trigger audible and visual alarms. They unlock and standby after the rail temperature meets construction conditions. When the rail temperature is greater than or equal to -20℃, proceed to step S3. S3: Rail-expanding scheme generation and automatic alignment: Input the workstation distance and maximum target rail-expanding displacement parameters into the host machine's human-machine interface. The host PLC control module calls the gradual rail-expanding displacement allocation algorithm, using the center of the track slab to be replaced as the coordinate origin. The coordinates increase along the track expansion device direction on both sides of the line, generating a rail-expanding displacement curve with the maximum lateral target displacement on one side of the rail at the center of the replacement slab, gradually decreasing to zero towards the two ends of the rail expansion device. This allocates the target stroke of each stage of the push rods of the two sets of rail-expanding devices. The PLC control module controls... Two sets of rail-expanding devices are controlled to move to the preset work position and automatically brake and lock; S4, graded progressive rail expansion and voltage stabilization: The first-stage pre-expanding push rods of the two sets of rail-expanding devices are controlled to extend synchronously for pre-expanding and pressure relief. After the first-stage pre-expanding push rods reach the preset stroke, the graded rail expansion and voltage stabilization delay algorithm is called to calculate the voltage stabilization time for this stage. The two sets of rail-expanding devices are simultaneously de-energized, self-locked, and stabilized; The second-stage intermediate-expanding push rods of the two sets of rail-expanding devices are controlled to extend synchronously for intermediate rail expansion. After the second-stage intermediate-expanding push rods reach the position, the graded rail expansion and voltage stabilization delay algorithm is called to obtain the voltage stabilization time. The two sets of rail-expanding devices are simultaneously de-energized, self-locked, and stabilized with a delay; The third-stage final-expanding push rods of the two sets of rail-expanding devices are controlled to extend synchronously according to the target stroke for final-state rail expansion, forming a steel rail that is large in the middle and small at both ends. The track gradually changes its alignment; after each push rod reaches its position, the graded track expansion voltage stabilization delay algorithm is called to automatically calculate the voltage stabilization holding time for that stage; S5, real-time safety monitoring and interlocking protection: the entire track expansion process calls the dual-machine synchronous deviation judgment algorithm. When 2mm < ΔS ≤ 5mm, speed reduction adjustment is triggered and the output speed of the push rod on the leading side is halved. When ΔS > 5mm, the two sets of track expansion devices are synchronously locked and the push rod is stopped through the dual-channel interlocking of industrial Ethernet and safety IO hard-wired, and an audible and visual alarm is triggered, allowing only retraction and reset. The displacement difference between the left and right rails inside a single track expansion device is also executed according to the two-level judgment criteria of 2mm and 5mm; the entire track expansion process also calls the track expansion safety boundary joint judgment algorithm, and simultaneously monitors the actual track expansion displacement S on one side of the rail. real and the actual strain ε of the rail rail When S real >750mm or ε rail >250×10-6 At the same time, the dual machines synchronously cut off the power output of the pusher, the mechanical stop physically restricts the push rod from continuing to extend, and triggers interlocking through dual channels of industrial Ethernet and safety IO hard-wired, with audible and visual alarms, allowing only the retraction reset procedure to be executed; S6, Track slab replacement: After the three-stage track expansion is completed and the device is self-locking and stable, the old type III slab is removed, the base is cleaned, the new slab is fine-tuned, the self-compacting concrete is poured and cured in sequence using the working space reserved between the two sets of track expansion devices; S7, Staged reset and data archiving: Start after the track reset conditions are met. The reset procedure involves two sets of rail-expanding devices retracting in the reverse order of rail expansion, from the third-stage final expansion push rod to the second-stage intermediate expansion push rod to the first-stage pre-expanding push rod. After each stage of retraction is completed, a graded rail-expanding voltage stabilization delay algorithm is invoked to perform short-term voltage stabilization. The external composite vertical support sliding unit returns to its position synchronously with the rail. After construction is completed, the construction data is exported and stored, and the track geometry is remeasured. If a 750mm overtravel or strain over-limit alarm is triggered during construction, on-site safety must be confirmed before retraction reset and alarm lockout can be performed.

[0015] Preferably, the present invention further includes: the gradual track expansion displacement allocation algorithm, which takes the center of the track slab to be replaced as the coordinate origin x=0, and increases the coordinate x along the track towards the track expansion devices on both sides, 0≤x≤L, generating a track expansion displacement curve with the largest single-sided lateral target displacement at the center of the replacement slab and gradually decreasing to zero towards the track expansion devices at both ends, characterized by a large displacement in the middle and small displacement at both ends; the gradual track expansion displacement allocation algorithm adopts a quadratic parabolic distribution model, as shown in the following formula: S(x)=S max (1-(x / L) 2 S(x) represents the lateral displacement of the rail at position x, where x is the longitudinal distance from the calculation point to the center of the track slab to be replaced. At the center, x = 0, and x increases towards the rail expansion devices at both ends, ranging from 0 to L, where L is the longitudinal distance from the center of the replacement slab to a single rail expansion device. max It is the maximum single-sided rail expansion displacement at the center of the plate changing point. The displacement towards the two end rail expansion device positions x=L is reduced to 0, not exceeding 750mm.

[0016] Preferably, the present invention further includes: calling the dual-machine synchronization deviation determination algorithm throughout the track expansion process, defined as: ΔS=|S host -S slave |;S host For the actual measured single-sided track expansion displacement of the main unit, S slaveTo measure the single-sided rail expansion displacement of the slave device, a first-level threshold ΔS1 = 2mm and a second-level threshold ΔS2 = 5mm are set. When 2mm < ΔS ≤ 5mm, a speed reduction adjustment is triggered, and the output speed of the push rod on the leading side is halved for dynamic correction. When ΔS > 5mm, it is determined that the synchronization is seriously exceeded. The two rail expansion devices are synchronously locked and the push rail is stopped through dual-channel interlocking via industrial Ethernet and safety IO hard-wired interlocking, and an audible and visual alarm is triggered. Only retraction and reset are allowed. The difference in left and right rail displacement within a single rail expansion device is also set with two levels of criteria: 2mm and 5mm.

[0017] Preferably, the present invention further includes: invoking the joint determination algorithm for the track expansion safety boundary and the graded track expansion voltage stabilization delay algorithm throughout the track expansion process; the joint determination algorithm for the track expansion safety boundary simultaneously monitors S real and ε rail S real The actual rail expansion displacement on one side of the rail is measured using a laser rangefinder and a displacement sensor built into the push rod. ε rail To measure the actual strain of the rail using an external rail strain sensor, satisfying S real ≤750mm and ε rail ≤250×10 -6 When S real >750mm or ε rail >250×10 -6 At the same time, the dual machines synchronously cut off the rail pushing power and execute self-locking protection; in the graded rail expansion and voltage stabilization delay algorithm, the voltage stabilization holding time after each push rod is in place is T, T=T0+k×S step T0 = ​​2s, k = 0.04s / mm, where T0 is the basic stabilization time, taken as 2 seconds, k is the displacement time coefficient, taken as 0.04 seconds per millimeter, and S step This is the extension displacement of the push rod at this stage, in millimeters. The PLC control module automatically calculates the holding time for each stage.

[0018] Preferably, the present invention further includes: when displacement deviation exceeds the limit, overtravel, low temperature alarm, or network communication is interrupted, the two sets of rail expansion devices are triggered to synchronously lock the rail pushing action through dual channels of industrial Ethernet and safety IO hard-wired; an external expansion interface is connected to a composite vertical support sliding unit and a rail strain sensor, and after connection, rail strain over-limit interlocking is realized; each push rod automatically cuts off power and locks when it reaches the preset stroke or triggers the 750mm overtravel limit, and when one rail expansion device self-locks, the other rail expansion device self-locks synchronously.

[0019] Preferably, the present invention further includes: if a 750mm overtravel or strain over-limit alarm is triggered during the construction process, the retraction reset and alarm lock can only be performed after on-site safety is confirmed; after the construction is completed, the control system automatically exports and stores all construction data, including rail temperature, stroke of each push rod, dual-machine collaborative correction amount, alarm records and operation time, and re-measures the track geometry. After all indicators meet the acceptance standards of high-speed railway ballastless track, the track window replacement operation is completed.

[0020] Compared with the prior art, the advantages of this invention are: Two rail-expanding devices, one master and one slave, work in tandem. The master PLC generates a rail-expanding displacement curve with the maximum lateral target displacement on one side of the rail at the center of the slab, gradually decreasing to zero towards both ends. The target stroke of each push rod is allocated, automatically forming a gradually expanding rail profile with a larger displacement in the middle and smaller displacement at both ends. This effectively disperses the lateral stress of the rail, avoiding secondary defects such as rail damage, track slab edge cracking, and mortar extrusion damage caused by stress concentration. Simultaneously, a three-stage progressive rail-expanding process is employed: the first stage is pre-expanding and pressure relief; the second stage is moderate expansion; and the third stage is final expansion, progressing step by step. After each stage is completed, power is cut off, voltage is stabilized, and self-locking is performed, fully releasing residual stress in the rail and further reducing the risk of construction damage. In terms of safety protection, a 750mm dual overtravel limit switch (software and mechanical) is set to prevent excessive rail stress caused by excessive displacement. A -20℃ low-temperature rail temperature interlock is configured to avoid blind rail expansion in low-temperature brittle environments. Through dual-channel interlocking via industrial Ethernet and safety IO hard-wired connections, both devices are triggered to synchronously lock the rail pusher in case of excessive displacement deviation, overtravel, low-temperature alarm, or network communication interruption, ensuring safe dual-machine collaboration. Regarding measurement accuracy, the pusher rod is dual-calibrated with a built-in displacement sensor and laser rangefinder to eliminate mechanism gap errors and achieve a true closed-loop of actual rail displacement, meeting the millimeter-level construction requirements of high-speed rail. In terms of operational stability, the high-rigidity spider-like frame is symmetrically stressed, resisting rail displacement reaction deformation. Each pusher automatically cuts off power and locks itself when in place or exceeding limits, ensuring stable track gauge without rebound during operation. In terms of intelligence, the entire machine automates temperature measurement, automatic alignment, graded rail expansion, overtravel protection, reset, and data storage. An external interface is reserved for connecting strain sensors and rail support fixtures. Construction parameters and alarm records are automatically saved, the operation process is traceable, and the construction process is standardized. In addition, the machine can move directly on the track slab, adapting to the single-piece replacement of skylights on straight and conventional curved CRTS-Ⅲ type slabs, effectively shortening the tooling setup time and improving skylight construction efficiency. Attached Figure Description

[0021] Figure 1 A schematic diagram of the progressive track expansion device for replacing Type III ballastless track slabs; Figure 2 Top view of the progressive track expansion device for replacing Type III ballastless track slabs; Figure 3 Bottom view of the progressive track expansion device for replacing Type III ballastless track slabs; Figure 4 Side view of the progressive track expansion device for replacing Type III ballastless track slabs; Figure 5 Rear view of the progressive track expansion device for replacing Type III ballastless track slabs; Figure 6 Front view of the progressive track expansion device for replacing Type III ballastless track slabs; Figure 7 Schematic diagram of dual-machine collaborative gradual track expansion operation; Figure 8 Flowchart of dual-machine collaborative gradual track expansion construction; Figure 9 A schematic diagram of the improved spider skeleton structure; Figure 10 Improved spider skeleton side view; Figure 11 A schematic diagram of the improved multi-stage push rod structure; Figure 12 Improved front view of multi-stage push rod; In the diagram: 1. Spider-like skeleton; 2. Walking roller assembly; 3. Multi-stage electric push rod; 3.1. First-stage pre-expansion push rod; 3.2. Second-stage intermediate expansion push rod; 3.3. Third-stage final expansion push rod; 4. PLC control module; 5. Rail infrared thermometer; 6. Ballastless track type III plate; 7. Walking drive motor; 8. Laser rangefinder; 9. Support ear plate; 10. Rail; 11. Base plate; 11.1 Through hole; 12. Push rod body. Detailed Implementation

[0022] To make the purpose, principle and structure of the present invention clearer, the following description is provided in conjunction with the accompanying drawings and specific embodiments.

[0023] See Figures 1 to 12, the present invention provides a gradual track widening system and method for type III slab replacement of ballastless track, which is suitable for the skylight replacement construction of damaged unit slabs of CRTS type III slab ballastless track. During long-term service, the type III slab 6 of the ballastless track is prone to diseases such as slab cracking, mortar layer peeling, and structural settlement, requiring regular replacement; before replacement, the fasteners in the operation section need to be loosened, and the steel rail 10 is shifted to the outer side of the line to widen the track gauge, so as to form an operation space between the two sets of track widening devices for old slab removal, base cleaning, new slab fine adjustment, self-compacting concrete pouring and curing. The center of the slab replacement, that is, the geometric center of the single type III slab 6 of the ballastless track to be replaced along the line direction, is also the longitudinal midpoint of the reserved operation space between the two sets of track widening devices. More accurate and more automated track widening can make the steel rail 10 form a gradually shifting line shape that is large in the middle and small at both ends, reduce the stress concentration of the steel rail 10 and the type III slab 6 of the ballastless track, and realize standardized track widening operations with low stress, millimeter-level synchronization and safety interlock.

[0024] The gradual track widening system for type III slab replacement of ballastless track of this embodiment includes two identical sets of track widening devices and a PLC control module 4 integrated on the track widening devices; the two sets of track widening devices are respectively arranged at both ends of the type III slab 6 of the ballastless track to be replaced along the line direction, and an operation space for the type III slab 6 of the ballastless track to be replaced is reserved between each other. Each set of track widening device includes a spider-type framework 1, a traveling roller assembly 2, a traveling drive motor 7, a multi-stage electric push rod 3, a PLC control module 4, a steel rail infrared thermometer 5, a laser range finder 8 and a support lug plate 9.

[0025] Among them, the spider-type framework 1 is a king-shaped hollow spider-type framework, which serves as a bearing matrix. The specific structure of the king-shaped hollow spider-type framework is: a longitudinal rod arranged along the line direction, that is, the extending direction of the steel rail 10, and three cross rods substantially perpendicular to the extending direction of the steel rail 10. The cross rods pass through the longitudinal rod and are fixedly connected with the longitudinal rod. Each cross rod is bilaterally symmetrical with the longitudinal rod as the center. Both the cross rods and the longitudinal rod are arranged horizontally and have a hollow structure, presenting a "king" shape in top view projection. The cross rods extending from the longitudinal rod as the center to the vicinity of the steel rail 10 on both sides form a "spider leg-shaped" structure; the longitudinal rod and the cross rods thus form the main body of the spider-type framework 1 and its extension brackets, that is, the longitudinal rod constitutes the main body extending along the line direction, the part of the three cross rods that is cross-connected with the longitudinal rod constitutes the transverse main body, and the part of each cross rod extending to both sides of the longitudinal rod to the vicinity of the steel rail 10 constitutes the extension bracket. Both the main body and the extension brackets have a hollow structure, so as to reduce self-weight and ensure the rigidity against the counterforce of pushing the rail while bearing the multi-stage electric push rod 3. The spider-type framework 1 can be made of low-alloy high-strength steel, which has low-temperature impact toughness and is a rectangular hollow high-strength framework, which not only reduces self-weight, but also ensures the rigidity against the counterforce of pushing the rail, and is convenient for on-site transportation.

[0026] The spider-like frame 1 is uniformly equipped with walking roller assemblies 2 and walking drive motors 7 at its bottom. Both the walking roller assemblies 2 and the walking drive motors 7 are located at the bottom of the spider-like frame 1 and are connected by transmission, enabling the entire machine to move and align autonomously. The walking roller assemblies 2 avoid the support platform of the ballastless track III-type plate 6 and can move directly on the track plate surface. The head rollers can be equipped with transmission gears and connected to the walking drive motors 7. The PLC control module 4 controls the walking drive motors 7 to drive the entire machine to move, and automatically brakes and locks after reaching the preset point.

[0027] Six multi-stage electric actuators 3 are symmetrically arranged on the spider skeleton 1. These six actuators are divided into three groups along the longitudinal direction of the track: front, middle, and rear. The front group consists of the first-stage pre-expansion actuator 3.1, the middle group consists of the second-stage middle expansion actuator 3.2, and the rear group consists of the third-stage final expansion actuator 3.3. The maximum design stroke of the actuators in the front, middle, and rear groups increases progressively. The first-stage pre-expansion actuator 3.1 is located at the head of the spider skeleton 1, the second-stage middle expansion actuator 3.2 is located in the middle of the spider skeleton 1, and the third-stage final expansion actuator 3.3 is located at the tail of the spider skeleton 1.

[0028] The extension brackets at the front, middle and rear have left and right ends on their outer sides, and each end accommodates a multi-stage electric push rod 3. The push rod body 12 of the multi-stage electric push rod 3 is fixed to the extension bracket as a fixed end, and the telescopic end is set towards the direction close to the rail 10, so as to make free telescopic movement.

[0029] The extension support of the spider skeleton 1 is a hollow structure that completely encloses the multi-stage electric push rod 3. The push rod end of the multi-stage electric push rod 3 is vertically provided with a base plate 11. The periphery of the base plate 11 is fixedly connected to the inner wall of the hollow structure of the extension support, so that the base plate 11 and the extension support form an integral load-bearing connection.

[0030] The multi-stage electric push rod 3 includes a horizontally arranged push rod body 12 and a vertically arranged base plate 11 at the end of the push rod. The end of the push rod body 12 away from the rail 10 is fixedly connected to the vertical side of the base plate 11 to form an inner fixed support. The hollow structure of the extension bracket has a vertically arranged support ear plate 9 inside. The support ear plate 9 is a plate vertically arranged below the push rod body 12. Its top is connected to the end of the push rod body 12 away from the base plate 11, that is, the end close to the rail 10, to form a bottom-up fixed support. In this way, it cooperates with the base plate 11 to form multi-dimensional support for the multi-stage electric push rod 3, ensuring its directional consistency and verticality, and avoiding deflection due to gravity and reaction force, which would affect the accuracy of the rail expansion operation.

[0031] Furthermore, the base plate 11 of the multi-stage electric actuator 3 has through holes 11.1 with the same shape as the support ear plate 9. The support ear plate 9 and the base plate 11 are staggered left and right and aligned through the through holes 11.1. On the side projection plane, the support ear plate 9 and the base plate 11 form a mutually cooperating envelope, and the support ear plate 9 and the base plate 11 together form a staggered multi-stage support for the multi-stage electric actuator 3 in the upper and lower and left and right directions. In this way, during the extension and retraction of the multi-stage electric actuator 3, its fixed end, support end and envelope structure jointly bear the push rail reaction force, preventing the actuator from deflecting or drooping due to cantilever force, and ensuring that the extension and retraction directions of the six multi-stage electric actuators 3 are consistent.

[0032] Each of the multi-stage electric push rods 3 has a built-in displacement sensor that measures the lateral displacement of the multi-stage electric push rod 3. The end of the third-stage final expansion push rod 3.3 is also equipped with a mechanical stop, which, together with the built-in displacement sensor, forms a dual limit of software and mechanical control, setting the maximum safe limit for single-sided rail expansion to 750mm. The specific structure of the mechanical stop can be selected according to requirements. Preferably, in this embodiment, a limiting block can be fixedly set at the telescopic end of the third-stage final expansion push rod 3.3, and a fixed stop can be set at the corresponding position of the extension bracket of the spider skeleton 1. When the push rod extends to 750mm on one side, the limiting block abuts against the fixed stop, thereby physically limiting the push rod from extending further, forming a dual limit of software and mechanical control together with the built-in displacement sensor.

[0033] The spider-like skeleton 1 is also equipped with a rail infrared thermometer 5, which is located between the first-stage pre-expansion push rod 3.1 and the second-stage intermediate expansion push rod 3.2, and is used to collect the surface temperature of the rails 10 on both sides in real time.

[0034] The laser rangefinder 8 is positioned between the second-stage intermediate expansion push rod 3.2 and the third-stage final expansion push rod 3.3 on the spider-like frame 1. Its measurement object is directly the rail 10. The actual lateral displacement of the rail 10 is obtained by real-time acquisition of the lateral position change of the rail 10. The displacement sensor built into the push rod measures the extension and retraction stroke of the multi-stage electric push rod 3 itself. This stroke needs to be transmitted to the rail 10 through the push rod body 12, the base plate 11, the support ear plate 9, and the extension bracket. Inevitably, there are assembly gaps, fit gaps between the support ear plate 9 and the base plate 11, cumulative errors in the extension and retraction of the multi-stage push rods, and elastic deformation after being subjected to force, which cause a deviation between the extension amount of the push rod and the actual displacement amount of the rail 10. The PLC control module 4 performs a real-time dual comparison between the lateral displacement of the rail 10 directly measured by the laser rangefinder 8 and the push rod stroke measured by the push rod's built-in displacement sensor. The measurement value of the laser rangefinder 8 is used as the direct verification benchmark for the actual displacement of the rail 10, and the measurement value of the push rod's built-in displacement sensor is used as the control feedback for the push rod's output stroke. When the difference between the two is within the allowable range, it indicates that the mechanism clearance and elastic deformation have not significantly affected the rail expansion accuracy, and the system continues closed-loop control according to the push rod stroke. When the difference between the two exceeds the allowable range, it indicates that the transmission chain clearance or mechanism status is abnormal. The PLC control module 4 can then correct the target stroke or trigger the corresponding safety interlock, thereby effectively eliminating the measurement deviation caused by the mechanism clearance. This ensures that the rail expansion device's operating stroke forms a true closed loop with the actual displacement of the rail 10 as the final criterion, meeting the millimeter-level construction accuracy requirements of high-speed rail.

[0035] The PLC control module 4 is integrated on the front of the spider skeleton 1, and has a built-in industrial Ethernet communication module, a distributed clock synchronization module, and a safety IO hard-wired interlocking interface. The two rail expansion devices are configured as master and slave devices, respectively. The PLC control module 4 of the master rail expansion device is configured with a gradual rail expansion displacement distribution algorithm. This algorithm generates a rail expansion displacement curve with the largest single-sided lateral target displacement at the center of the plate changing center and gradually decreasing to zero towards the positions of the rail expansion devices at both ends. The PLC control module 4 of the master rail expansion device obtains the target output stroke of each push rod of the two rail expansion devices according to the curve, and sends timing and stroke commands to the slave device through the industrial Ethernet communication module. The distributed clock synchronization module is used to ensure that the sampling and output command timing of the two rail expansion devices are consistent. The safety IO hard-wired interlocking interface is set in parallel with the industrial Ethernet communication module and is connected to the PLC control module 4 of the two rail expansion devices and the push rod power circuit through hard wiring, respectively, as a hardware safety backup in case of Ethernet communication failure. The PLC control module 4 controls the first-stage pre-expansion push rod 3.1, the second-stage intermediate expansion push rod 3.2, and the third-stage final expansion push rod 3.3 of the two sets of track-expanding devices in a progressive manner according to the dual-machine coordinated gradual track-expanding sequence. After each push rod reaches the preset stroke, it controls the power-off voltage regulation and self-locking. The whole machine can also be powered by a power module, which can be arranged at the tail of the spider skeleton 1 to power the walking, push rod, sensing and control system.

[0036] PLC control module 4 also includes rail temperature safety interlock, automatic travel alignment, dual overtravel protection, multi-level power failure self-locking, fault-communication global interlock, and external expansion interface. The rail temperature safety interlock is preset to a -20℃ construction threshold. The rail infrared thermometer 5 collects the temperature of rail 10 in real time. When the temperature of rail 10 is below -20℃, both sets of rail-expanding devices simultaneously lock all rail-expanding actions and issue audible and visual alarms, prohibiting low-temperature rail-expanding operations. When the temperature of rail 10 is greater than or equal to -20℃, it unlocks and enters standby mode. Automatic travel alignment controls the travel drive motor 7 based on the workstation distance input through the human-machine interface and automatically brakes and locks upon reaching the preset point. The two sets of devices respectively complete the alignment of the two ends. Dual overtravel protection is implemented by either the built-in displacement sensor in the push rod or the laser rangefinder 8. If either signal detects a single-sided rail 10 extension displacement of 750mm, all push rod power output is cut off, and a mechanical stop restricts further extension. Only manual triggering of the retraction program is possible, prohibiting further outward movement of the rail 10. If either machine triggers overtravel, both devices simultaneously stop pushing the rail. Multi-stage power-off self-locking automatically cuts off power and locks when each push rod reaches its preset travel or triggers the 750mm overtravel limit, preventing gauge retraction and deviation. When one device self-locks, the other self-locks synchronously. Fault-communication global interlocking triggers both rail-expanding devices to synchronously lock the rail pushing action via dual channels of industrial Ethernet and safety IO hardwiring when displacement deviation exceeds limits, overtravel occurs, low temperature alarms occur, or network communication is interrupted. The external expansion interface is used to connect the composite vertical support sliding unit and the rail strain sensor. After connection, the rail 10 strain over-limit interlock is realized. The composite vertical support sliding unit can lift the rail 10 to prevent the rail 10 from being suspended and bent, resulting in permanent hard bending, and return to its original position synchronously with the rail 10.

[0037] The PLC control module 4 internally includes a pre-set rail gradual expansion displacement distribution model, a synchronization deviation judgment algorithm, an expansion safety boundary judgment model, and a graded expansion voltage stabilization delay algorithm, all of which are discretized and executed within the PLC. The gradual expansion displacement distribution algorithm uses the center of the ballastless track type III slab 6 to be replaced as the coordinate origin x=0, and the coordinate x increases along the track towards the expansion devices on both sides, 0≤x≤L, generating a mid-range large and end-range expansion displacement curve where the lateral target displacement of rail 10 at the center of the replacement slab is the largest, gradually decreasing to zero towards the expansion devices at both ends. This algorithm preferably uses a quadratic parabolic distribution model: S(x)=S max (1-(x / L) 2 ); where S(x) is the lateral target displacement of rail 10 on one side at position x, x is the longitudinal distance from the calculation point to the center of the ballastless track type III slab 6 to be replaced, x=0 at the center, and x increases towards the rail expansion devices at both ends, ranging from 0 to L, where L is the longitudinal distance from the center of the replacement slab to a single rail expansion device, S maxThe maximum single-sided track expansion displacement at the center of the plate changing device is no more than 750mm. The displacement towards the track expansion device positions x=L at both ends decreases to 0, forming a parabolic profile that is larger in the middle and gradually smaller at both ends. The PLC control module 4 of the main track expansion device calculates the target output stroke of each push rod of the two track expansion devices according to this formula and sends it to the slave device for execution; other gradual distribution models such as cosine curves can also be used to achieve the equivalent effect.

[0038] The algorithm for determining the synchronization deviation between two machines is defined as ΔS = |S host -S slave |, where S host For the actual measured single-sided track expansion displacement of the main unit, S slave To measure the single-sided rail expansion displacement of the slave device, a first-level threshold ΔS1 = 2mm and a second-level threshold ΔS2 = 5mm are set. When 2mm < ΔS ≤ 5mm, a speed reduction adjustment is triggered, and the output speed of the push rod on the leading side is halved for dynamic correction. When ΔS > 5mm, it is determined that the synchronization is seriously exceeded. The two rail expansion devices are synchronously locked and the push rod is triggered by dual-channel interlocking through industrial Ethernet and safety IO hard-wired connection, and an audible and visual alarm is triggered. Only retraction and reset are allowed. The displacement difference between the left and right rails 10 inside a single rail expansion device is also set with two-level criteria of 2mm and 5mm. The push rod on the leading side automatically reduces its speed, thereby controlling the overall rail expansion synchronization error to the millimeter level.

[0039] The joint algorithm for determining the safety boundary of rail expansion simultaneously monitors the actual rail expansion displacement S on one side of rail 10. real And the actual strain ε of the rail 10 rail S real The actual single-sided rail expansion displacement ε of rail 10 was measured using the laser rangefinder 8 and the displacement sensor built into the push rod. rail To measure the actual strain of rail 10 using an external rail strain sensor, satisfying S real ≤750mm and ε rail ≤250×10 -6 When S real >750mm or ε rail >250×10 -6 At this time, the dual machines synchronously cut off the power output of the pusher rail, the mechanical stop physically restricts the push rod from continuing to extend, and triggers interlocking through dual channels of industrial Ethernet and safety IO hard-wired, with audible and visual alarms, allowing only the retraction reset procedure to be executed.

[0040] In the graded expansion and voltage stabilization delay algorithm, the voltage stabilization holding time after each push rod reaches its position is T, where T = T0 + k × S. step T0 = ​​2s, k = 0.04s / mm, where T0 is the basic stabilization time, taken as 2 seconds, and k is the displacement time coefficient, taken as 0.04 seconds per millimeter. stepThis is the extension displacement of the push rod at this stage, in millimeters. The PLC control module 4 automatically calculates the holding time for each stage without manual setting. The larger the extension displacement, the longer the stabilization time automatically becomes, fully releasing the residual stress inside the rail 10 and avoiding stress lag.

[0041] During use, the two rail-expanding devices are transported to both ends of the ballastless track type III slab 6 to be replaced along the track direction, with a reserved space between the two sets of rail-expanding devices for the replacement of the ballastless track type III slab 6. After the equipment is powered on, a master-slave communication link is established through industrial Ethernet. The distributed clock synchronization module completes hardware time synchronization, confirms the integrity of the safety IO hard-wired interlocking circuit connection, and completes the dual-machine collaborative link self-test. The two sets of devices perform a complete machine self-test, checking whether the push rod communication status, rail infrared thermometer 5, laser rangefinder 8, walking drive motor 7, dual-machine network communication, hard-wired interlocking circuit, and other signals are normal. The rail infrared thermometer 5 collects the surface temperature of the rails 10 on both sides in real time. When the temperature of the rails 10 is below -20℃, the two sets of rail-expanding devices simultaneously lock all rail-expanding actions and issue audible and visual alarms. After the rail temperature meets the construction conditions, they unlock and standby. When the temperature of the rails 10 is greater than or equal to -20℃, the rail-expanding scheme is generated and automatically aligned. Input the station distance and maximum target track expansion displacement parameters into the host human-machine interface. The PLC control module 4 of the host track expansion device calls the gradual track expansion displacement allocation algorithm. Taking the center of the ballastless track type III plate 6 to be replaced as the coordinate origin, the coordinate increases along the track to both sides of the track expansion device direction, generating a track expansion displacement curve with the maximum single-sided lateral target displacement at the center of the replacement plate and gradually decreasing to zero at both ends. Allocate the target stroke of each stage of the push rod of the two sets of track expansion devices. The PLC control module 4 controls the two sets of track expansion devices to move to the preset station and automatically brake and lock.

[0042] Subsequently, graded and progressive rail expansion and voltage stabilization are performed. The first-stage pre-expansion push rods 3.1 of the two rail expansion devices extend synchronously for pre-expansion and pressure relief. After the first-stage pre-expansion push rods 3.1 reach their preset stroke, the graded rail expansion and voltage stabilization delay algorithm is invoked to calculate the stabilization time for this stage. Both rail expansion devices simultaneously de-energize, self-lock, and stabilize voltage. The second-stage intermediate expansion push rods 3.2 of the two rail expansion devices extend synchronously for moderate rail expansion. After the second-stage intermediate expansion push rods 3.2 reach their positions, the graded rail expansion and voltage stabilization delay algorithm is invoked to obtain the stabilization duration. Both rail expansion devices simultaneously de-energize, self-lock, and stabilize voltage after a delay. The third-stage final expansion push rods 3.3 of the two rail expansion devices extend synchronously according to the target stroke for final-state rail expansion, forming a gradually changing rail expansion profile (10) with a larger middle section and smaller ends. After each push rod reaches its position, the graded rail expansion and voltage stabilization delay algorithm automatically calculates the stabilization holding time for this stage. After stress release is complete, the next stage of action begins. The entire rail expansion process utilizes a dual-machine synchronous deviation judgment algorithm. When 2mm < ΔS ≤ 5mm, a speed reduction adjustment is triggered, halving the output speed of the leading push rod. When ΔS > 5mm, the two rail expansion devices are synchronously locked and the push rod is activated via a dual-channel interlock using industrial Ethernet and hard-wired safety I / O, triggering an audible and visual alarm and allowing only retraction and reset. The displacement difference between the left and right rails 10 within a single rail expansion device is also judged according to two levels of criteria: 2mm and 5mm. The entire rail expansion process also utilizes a joint judgment algorithm for rail expansion safety boundaries, simultaneously monitoring the actual rail expansion displacement S on one side of rail 10. real And the actual strain ε of the rail 10 rail When S real >750mm or ε rail >250×10 -6 When either device synchronously cuts off the power output to the rail pusher, the mechanical stop physically restricts the push rod from extending further, and the interlock is triggered via dual channels of industrial Ethernet and safety I / O hardwired connection, triggering an audible and visual alarm. Only the retraction reset procedure is allowed to be executed. When either device triggers the upper limit of displacement or the rail strain exceeds the limit, both devices immediately and synchronously cut off the power output to all push rods, the mechanical stop physically prevents the push rod from extending further, and the interlock is triggered via dual channels of Ethernet and safety I / O hardwired connection, triggering an audible and visual alarm. Only the retraction reset procedure is allowed to be executed. The overall rail expansion synchronization error is controlled within the millimeter level.

[0043] After the three-stage track expansion is completed and the device is self-locking and stable, the track gauge remains constant. Utilizing the working space reserved between the two track expansion devices, the old ballastless track type III slab 6 is dismantled, the base is cleaned, the new slab is fine-tuned, self-compacting concrete is poured, and curing is carried out sequentially. Once the track reset conditions are met, the reset procedure is initiated. The two track expansion devices retract in the reverse order of track expansion, from the third-stage final expansion push rod 3.3 to the second-stage intermediate expansion push rod 3.2 to the first-stage pre-expansion push rod 3.1. After each stage of retraction, the graded track expansion and pressure stabilization delay algorithm is invoked to perform short-term pressure stabilization, slowly releasing the lateral preload of rail 10 to prevent rail 10 from rebounding and shifting. The external composite vertical support sliding unit follows rail 10 back to its synchronous position. After construction is completed, the construction data is exported and stored, and the track geometry is remeasured. The construction data includes rail temperature, push rod stroke at each stage, dual-machine collaborative correction amount, alarm records, and operation time. The track geometry is remeasured, and after all indicators meet the high-speed railway ballastless track acceptance standards, the track slab replacement operation is completed. If a 750mm overtravel or strain over-limit alarm is triggered during construction, the retraction reset and alarm lockout can only be performed after on-site safety has been confirmed.

[0044] In an improved embodiment, the structure of the spider-like frame 1 and the multi-stage electric actuator 3 can be further improved, while the installation of other components and system control remain the same as in the aforementioned embodiment. The improvement to the spider-like frame 1 mainly lies in the extension of the support bracket carrying the multi-stage electric actuator 3. A hollow bracket completely encloses the multi-stage electric actuator 3, serving three main purposes: first, to prevent the multi-stage electric actuator 3 from colliding with other equipment or components and causing damage; second, the extension of the hollow frame prevents rain, snow, and other severe weather conditions from affecting the use of the multi-stage electric actuator 3; and third, a support ear plate 9 is provided inside the extended bracket to support the multi-stage electric actuator 3, preventing deformation due to changes in the center of gravity during prolonged use and during the actuator's advancement stroke, thus avoiding interference with the control system's judgment of the multi-stage electric actuator 3. The improvement to the multi-stage electric actuator 3 mainly lies in the improvement of the base plate 11. A through hole 11.1 of the same shape as the support ear plate 9 is cut into the base plate 11 to facilitate the installation and fixation of the multi-stage electric actuator 3. With the above structure, the left and right ends of the outer sides of the three extension brackets at the front, middle, and rear respectively accommodate multi-stage electric push rods 3. The push rod body 12 is fixed to the extension bracket as a fixed end, and the telescopic end is set towards the direction close to the rail 10, allowing for free telescopic movement. The end of the push rod body 12 away from the rail 10 is fixedly connected to the vertical side of the base plate 11, forming an inner fixed support. The support ear plate 9 is a plate set vertically below the push rod body 12, and its top and the end of the push rod body 12 close to the rail 10 form a bottom-up fixed support, thus cooperating with the base plate 11 to form multi-dimensional support for the multi-stage electric push rods 3, ensuring their directional consistency and verticality, and avoiding deflection due to gravity and reaction force, which would affect the accuracy of the track expansion operation. The whole machine can directly walk on the ballastless track type III slab 6, and is suitable for single-piece replacement skylight operations on straight lines and conventional curves of CRTS-III type slabs, effectively shortening the tooling layout time and improving the efficiency of skylight construction. The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present invention, based on the technical solution and concept of the present invention, should be covered within the scope of protection of the present invention.

[0045] The above description is merely a specific embodiment of the invention, but the scope of protection of the invention is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the invention, based on the technical solution and concept of the invention, should be covered within the scope of protection of the invention.

Claims

1. A progressive track expansion system for replacing Type III ballastless track slabs, characterized in that, comprising two identical rail widening devices and a PLC control module integrated on the rail widening devices; The two rail widening devices are respectively arranged at both ends of the track slab to be replaced along the line direction, with an operation space for the track slab to be reserved therebetween, and each set of the rail widening device includes: a king-shaped hollow spider-type framework, which serves as a bearing base body; a traveling roller assembly and a traveling drive motor, both arranged at the bottom of the king-shaped hollow spider-type framework and in transmission connection with each other; six multi-stage electric push rods, which are respectively arranged symmetrically left and right on the king-shaped hollow spider-type framework, and divided into a front group, a middle group and a rear group along the longitudinal direction of the line, wherein the front group is a first-stage pre-widening push rod, the middle group is a second-stage intermediate widening push rod, the rear group is a third-stage final widening push rod, and the maximum design strokes of the front, middle and rear groups of push rods increase step by step; a plurality of displacement sensors, which are respectively built in the six multi-stage electric push rods and configured to measure the lateral displacement of the multi-stage electric push rods; and a laser range finder, which is arranged on the king-shaped hollow spider-type framework and configured to measure the lateral displacement of the steel rail; The displacement sensors built in the push rods and the laser range finder form double comparison of the operation stroke of the rail widening device; the end of the third-stage final widening push rod is further provided with a mechanical stop, which forms dual limit of software and machinery with the built-in displacement sensor; The king-shaped hollow spider-type framework is further provided with a steel rail infrared thermometer; The PLC control module is integrated on the front side of the king-shaped hollow spider-type framework, and is internally provided with an industrial Ethernet communication module, a distributed clock synchronization module and a safety IO hard-wired interlock interface; The two rail widening devices are respectively configured as a master unit and a slave unit, the PLC control module of the master rail widening device is configured with a gradual rail widening displacement distribution algorithm, the algorithm generates a rail widening displacement curve with a large middle part and small two ends, wherein the maximum single-side lateral target shifting amount of the steel rail at the center of slab replacement is maximum, and the shifting amount gradually attenuates to zero towards the positions of the rail widening devices at both ends; the PLC control module of the master unit obtains the target output stroke of each push rod of the two rail widening devices according to the curve, and issues time sequence and stroke instructions to the slave unit through the industrial Ethernet communication module; The distributed clock synchronization module is used for controlling the sampling and output instruction time sequences of the two rail widening devices to be consistent; the safety IO hard-wired interlock interface is arranged in parallel with the industrial Ethernet communication module, and is respectively connected with the PLC control modules and the push rod power loops of the two rail widening devices through hard wires; The PLC control module controls the first-stage pre-widening push rods, the second-stage intermediate widening push rods and the third-stage final widening push rods of the two rail widening devices to advance step by step according to the dual-machine cooperative gradual rail widening time sequence, and controls power-off voltage-stabilizing self-locking after each stage of push rods reaches a preset stroke.

2. The gradual rail widening system for type III slab replacement of ballastless track according to claim 1, characterized in that, the king-shaped hollow spider-type framework comprises extension brackets for bearing the multi-stage electric push rods, and the extension brackets are of hollow structures and completely enclose the multi-stage electric push rods; each of the multi-stage electric push rods comprises a horizontally arranged push rod body and a bottom plate vertically arranged at the tail end of the push rod, and the periphery of the bottom plate is fixedly connected with the inner side wall of the hollow structure of the extension bracket. The hollow structure of the extension bracket has a vertically arranged support ear plate inside. The support ear plate is connected to the side of the push rod body away from the base plate. The base plate of the multi-stage electric push rod has a through hole with the same shape as the support ear plate. The support ear plate and the base plate are staggered left and right and are aligned through the through hole. On the lateral projection plane, the support ear plate and the base plate form a mutually cooperating envelope, and together they form a multi-level support for the multi-stage electric push rod, alternating between vertical and horizontal.

3. The ballastless track type III slab replacement progressive track expansion system as described in claim 1, characterized in that, The rail infrared thermometer is installed between the first-stage pre-expansion push rod and the second-stage intermediate expansion push rod on the king-shaped hollow spider skeleton. The laser rangefinder is positioned between the second-stage intermediate expansion push rod and the third-stage final expansion push rod on the king-shaped hollow spider skeleton.

4. The ballastless track type III slab replacement progressive track expansion system as described in claim 1, characterized in that, The PLC control module is also equipped with rail temperature safety interlock, automatic travel alignment, dual overtravel protection, multi-level power failure self-lock, fault-communication global interlock and external expansion interface; The rail temperature safety interlock is preset to a construction threshold of -20℃. The automatic walking alignment controls the walking drive motor based on the work position distance input by the human-machine interface and automatically brakes and locks when it reaches the preset point. The dual overtravel protection is triggered by either the displacement sensor built into the push rod or the laser rangefinder signal. When either signal detects that the rail expansion displacement on one side reaches 750mm, all push rod power output is cut off and mechanical stop restricts the push rod from continuing to extend. The multi-stage power-off self-locking automatically cuts off power and locks when each push rod reaches the preset stroke or triggers the 750mm overtravel limit. When one push rod self-locks, the other self-locks synchronously. The fault-communication global interlock triggers two sets of rail expansion devices to synchronously lock the rail pushing action through dual channels of industrial Ethernet and safety IO hard-wired when the displacement deviation exceeds the limit, overtravel occurs, low temperature alarm occurs, or network communication is interrupted. The external expansion interface is used to connect the composite vertical support sliding unit and the rail strain sensor.

5. A method for progressively expanding the track by replacing Type III slabs of ballastless track, characterized in that, The progressive track expansion system for replacing ballastless track type III slabs as described in any one of claims 1 to 4 includes the following steps: S1. Construction preparation and communication self-test: Transfer the two sets of track expansion devices to the two ends of the CRTSⅢ type track slab to be replaced along the line direction, and reserve the track slab replacement operation space between the two sets of track expansion devices; after the equipment is powered on, establish a master-slave communication link through industrial Ethernet, the distributed clock synchronization module completes hardware time synchronization, confirms that the safety IO hard-wired interlocking line is connected well and completes the dual-machine collaborative link self-test. S2. Rail temperature safety interlock judgment: The infrared thermometer collects the surface temperature of the rails on both sides in real time. When the rail temperature is below -20℃, the two rail expansion devices lock all rail expansion actions simultaneously and sound and light alarms. The device is unlocked and put into standby mode after the rail temperature meets the construction conditions. When the rail temperature is greater than or equal to -20℃, proceed to step S3. S3. Rail expansion scheme generation and automatic alignment: Input the station distance and maximum target rail expansion displacement parameters into the host human-machine interface. The host PLC control module calls the gradual rail expansion displacement allocation algorithm. Taking the center of the rail plate to be replaced as the coordinate origin, the coordinate increases along the line towards the rail expansion devices on both sides. Generate a rail expansion displacement curve with the maximum lateral target displacement on one side of the rail at the center of the replacement plate and gradually decreases to zero towards the positions of the rail expansion devices at both ends. Allocate the target stroke of each stage of the push rod of the two sets of rail expansion devices. The PLC control module controls the two sets of rail expansion devices to move to the preset station and automatically brakes and locks. S4. Gradual expansion of rails and voltage stabilization: The first-stage pre-expansion push rods of the two sets of rail expansion devices extend synchronously to perform pre-expansion and pressure relief. After the first-stage pre-expansion push rods reach the preset stroke, the graded rail expansion and voltage stabilization delay algorithm is called to calculate the voltage stabilization time of this stage. The two sets of rail expansion devices are simultaneously de-energized, self-locked, and stabilized. The second-stage intermediate expansion push rods of the two sets of rail expansion devices extend synchronously to perform medium rail expansion. After the second-stage intermediate expansion push rods are in place, the graded rail expansion voltage stabilization delay algorithm is called to obtain the voltage stabilization time. The two sets of rail expansion devices are simultaneously powered off, self-locked, and delayed to stabilize the voltage. The third-stage final expansion push rod of the two sets of rail expansion devices extends synchronously according to the target stroke to perform final rail expansion, forming a gradually expanding rail shape with a larger middle and smaller ends; after each push rod is in place, the graded rail expansion voltage stabilization delay algorithm is called to automatically calculate the voltage stabilization holding time of this stage. S5. Real-time safety monitoring and interlocking protection: The entire track expansion process uses a dual-machine synchronous deviation judgment algorithm. When 2mm < ΔS ≤ 5mm, a speed reduction adjustment is triggered and the output speed of the push rod on the leading side is halved. When ΔS > 5mm, the two sets of track expansion devices are synchronously locked and the push rail is stopped through industrial Ethernet and safety IO hard-wired dual-channel interlocking, and an audible and visual alarm is triggered. Only retraction and reset are allowed. The displacement difference between the left and right rails inside a single track expansion device is also judged according to the two-level criteria of 2mm and 5mm. The entire rail widening process also utilizes a joint judgment algorithm for rail widening safety boundaries, while simultaneously monitoring the actual rail widening displacement S on one side. real and the actual strain ε of the rail rail When S real >750mm or ε rail >250×10 -6 At this time, the dual machines synchronously cut off the power output of the pusher rail, the mechanical stop physically restricts the push rod from continuing to extend, and triggers the interlock through the dual channels of industrial Ethernet and safety IO hard-wired, with audible and visual alarms, and only allows the retraction reset procedure to be executed; S6. Track slab replacement: After the three-stage track expansion is completed and the device is self-locking and stable, the old Type III slab is removed, the base is cleaned, the new slab is finely adjusted, the self-compacting concrete is poured and cured in sequence using the working space reserved between the two sets of track expansion devices. S7. Staged Reset and Data Archiving: After the track reset conditions are met, the reset procedure is initiated. The two sets of track expansion devices retract in the reverse order of track expansion, from the third-stage final expansion push rod to the second-stage intermediate expansion push rod to the first-stage pre-expansion push rod. After each stage of retraction is completed, the staged track expansion voltage stabilization delay algorithm is called to perform short-term voltage stabilization. The external composite vertical support sliding unit follows the rail and returns to its position synchronously. After construction is completed, the construction data is exported and stored, and the track geometry is remeasured. If a 750mm overtravel or strain over-limit alarm is triggered during construction, the retraction reset and alarm lock can only be performed after on-site safety is confirmed.

6. The method for replacing Type III ballastless track slabs with progressive track expansion as described in claim 5, characterized in that, The gradual track expansion displacement allocation algorithm takes the center of the track slab to be replaced as the coordinate origin x=0, and increases the coordinate x along the track towards the track expansion devices on both sides, 0≤x≤L, generating a track expansion displacement curve with the largest single-sided lateral target displacement at the center of the replacement slab and gradually decreasing to zero towards the track expansion devices at both ends. The gradual track expansion displacement allocation algorithm adopts a quadratic parabolic distribution model, as shown in the following equation: S(x)=S max (1-(x / L) 2 ); S(x) is the lateral target displacement of the rail at position x, where x is the longitudinal distance from the calculation point to the center of the track slab to be replaced. At the center, x = 0, and x increases towards the rail expansion devices at both ends, ranging from 0 to L, where L is the longitudinal distance from the center of the replacement slab to a single rail expansion device. max It is the maximum single-sided rail expansion displacement at the center of the plate changing point. The displacement towards the two end rail expansion device positions x=L is reduced to 0, not exceeding 750mm.

7. The method for replacing Type III ballastless track slabs with progressive track expansion as described in claim 5, characterized in that, The entire track expansion process utilizes a dual-machine synchronization deviation determination algorithm, defined as follows: ΔS=|S host -S slave |; S host For the actual measured single-sided track expansion displacement of the main unit, S slave This is a measurement of the single-sided track expansion displacement by the slave unit. Set the first-level threshold ΔS1=2mm and the second-level threshold ΔS2=5mm; When 2mm<ΔS≤5mm, speed reduction adjustment is triggered, and the output speed of the push rod on the leading side is halved for dynamic correction. When ΔS > 5mm, it is determined that the synchronization is seriously out of limit. The two sets of rail extension devices are synchronously locked and the push rail is stopped by industrial Ethernet and safety IO hard-wired dual-channel interlocking, and an audible and visual alarm is triggered. Only retraction and reset are allowed. The displacement difference between the left and right rails inside a single rail expansion device is also set with two levels of criteria: 2mm and 5mm.

8. The method for replacing Type III ballastless track slabs with progressive track expansion as described in claim 5, characterized in that, The entire track expansion process utilizes the joint determination algorithm for track expansion safety boundaries and the graded track expansion voltage stabilization delay algorithm. The joint determination algorithm for extended orbit safety boundaries simultaneously monitors S real and ε rail S real The actual rail expansion displacement on one side of the rail is measured using a laser rangefinder and a displacement sensor built into the push rod. ε rail To measure the actual strain of the rail using an external rail strain sensor, satisfying S real ≤750mm and ε rail ≤250×10 -6 When S real >750mm or ε rail >250×10 -6 At the same time, the two machines simultaneously cut off the power to push the rail and execute self-locking protection; In the graded track expansion and voltage stabilization delay algorithm, the voltage stabilization holding time after each push rod reaches its position is T. T=T0+k×S step ,T0=2s,k=0.04s / mm, Where T0 is the basic stabilization time, taken as 2 seconds, k is the displacement time coefficient, taken as 0.04 seconds per millimeter, and S... step This is the extension displacement of the push rod at this stage, in millimeters. The PLC control module automatically calculates the holding time for each stage.

9. The method for replacing Type III ballastless track slabs with progressive track expansion as described in claim 5, characterized in that, When displacement deviation exceeds the limit, overtravel, low temperature alarm or network communication interruption occurs, the two sets of rail extension devices are triggered to lock the rail pushing action synchronously through dual channels of industrial Ethernet and safety IO hard wiring. The external expansion interface connects to the composite vertical support sliding unit and the rail strain sensor, and after connection, the rail strain over-limit interlock is realized; when each push rod reaches the preset stroke or triggers the 750mm over-stroke limit, it automatically cuts off the power and locks; when one rail expansion device self-locks, the other rail expansion device self-locks synchronously.

10. The method for replacing Type III ballastless track slabs with progressive track expansion as described in claim 5, characterized in that, If the 750mm overtravel or strain over-limit alarm is triggered during construction, the retraction reset and alarm lockout can only be performed after on-site safety is confirmed. After construction is completed, the control system automatically exports and stores all construction data, including rail temperature, stroke of each push rod, amount of dual-machine coordinated correction, alarm records and operation time. The track geometry is re-measured, and the track replacement work is completed after all indicators meet the acceptance standards for high-speed railway ballastless track.

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