Fastener assembly with retaining shoulder for rail transit

Abstract

The utility model relates to a retaining shoulder fastener assembly for rail transit, which is characterized in that an elastic strip, an iron backing plate and an elastic backing plate are fixed on a sleeper through threaded occlusion of a screw spike and an embedded sleeve, a flat washer is arranged between the screw spike and the elastic strip, the iron backing plate is arranged at the upper part of the elastic backing plate, and a round hole is formed in the middle of the elastic backing plate. The elastic base plate and the iron base plate are limited through bolt holes; an under-rail backing plate is arranged at the upper part of the iron backing plate and is in direct contact with the steel rail, an insulating rail gauge block is buckled on the steel rail in a limiting manner, a rail gauge baffle is placed on the other side of the screw spike, and an elastic strip is buckled above the rail gauge baffle and the insulating rail gauge block; a fine adjustment base plate is arranged between the iron base plate and the under-rail base plate, and a height adjustment base plate is arranged between the elastic base plate and the sleeper. By optimizing the structures of the elastic base plate, the elastic strip, the iron base plate and the gauge stop block, the torsional rigidity is increased, the resonance problem is relieved, the steel rail adjusting capacity is increased, and the fastener application performance is improved.

Description

Technical Field

[0001] This utility model relates to the field of rail transit technology, and in particular to a rail transit component with a shoulder fastener. Background Technology

[0002] With the rapid development of intercity, suburban, and urban rail transit in my country, the adaptability of existing WJ-7 and WJ-8 fastening systems in complex operating environments is becoming increasingly apparent. Technically, while the WJ-7 and WJ-8 fastening systems, widely used on high-speed railways, meet the design speed and axle load requirements of intercity, suburban, and urban rail transit, in actual operation, these lines often have small-radius curves. In these sections, the lateral load on trains is greater, and the lateral displacement of the rail head is significant. The existing fastening systems' lateral load resistance, torsional stiffness, and lateral adjustment capabilities are insufficient to cope with these conditions, leading to severe rail wear and high maintenance costs.

[0003] Regardless of whether the existing fastening system is applied to high-speed railways or small-radius curves in intercity and urban rail lines, the measured natural frequency (650Hz~740Hz) of the elastic clips in the fastening system highly overlaps with the wheel-rail excitation frequency band, easily causing resonance and leading to clip breakage. Simultaneously, the spiral spikes in the existing fastening system exhibit abnormal loosening under abnormal hammering, with some spiral spikes loosening or rapidly rotating out. Regarding the lateral adjustment capability of the rail, the WJ-7 and WJ-8 fasteners offer lateral adjustments of ±6mm and ±5mm respectively, which is insufficient to meet the actual needs of subsequent maintenance and repair, necessitating optimization of the fasteners and key components.

[0004] Therefore, the existing WJ-7 and WJ-8 fastener systems cannot simultaneously meet the diversified operational needs of high-speed railways and rail transit in sections with small-radius curves. Furthermore, the instability in the existing fastener systems severely restricts the long-term stability and operational economy of the track structure. These defects have become key bottlenecks restricting the high-quality development of new rail transit networks. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention creates a circular hole in the center of the elastic pad, maintaining the overall stiffness while reducing the stiffness in the center and increasing the stiffness on both sides, effectively increasing torsional stiffness and preventing rail rollover. Furthermore, this invention optimizes the elastic clip structure to increase its natural frequency, optimizes the spiral spike structure, and improves the rail adjustment capability by optimizing the iron pad and gauge block structure.

[0006] To achieve the above objectives, the technical solution adopted by this utility model includes:

[0007] A shoulder fastener assembly for rail transit, characterized in that it comprises:

[0008] The elastic clip, iron pad, and elastic pad are fixed to the sleeper by the threaded engagement of the spiral spike and the pre-embedded sleeve. A flat washer is provided between the spiral spike and the elastic clip. The iron pad is on the upper part of the elastic pad. A round hole is provided in the middle of the elastic pad. Bolt holes are provided at both ends of the elastic pad. The iron pad is provided with a shoulder and bolt holes. The elastic pad and the iron pad are limited by the bolt holes.

[0009] A rail pad is provided on the upper part of the iron pad plate. The rail pad is in direct contact with the rail. An insulating gauge block is pressed onto the rail. A gauge baffle is placed on the other side of the spiral spike. The elastic bar is pressed onto the gauge baffle and the insulating gauge block.

[0010] A fine-adjustment shim is provided between the iron pad and the rail pad, and a height adjustment shim is provided between the elastic pad and the sleeper.

[0011] Furthermore, the top of the threads of the spiral spike is chamfered.

[0012] Furthermore, the rail bearing surface of the iron pad does not have a limiting boss, and the bolt holes of the iron pad are set as U-shaped grooves or extended at both ends.

[0013] Furthermore, the bolt holes of the elastic pad are configured as U-shaped grooves or extended ends.

[0014] Furthermore, when the bolt holes of the iron pad are U-shaped grooves, the lateral engagement position is adjusted by fixing the U-shaped grooves of the iron pad with the spiral rail spike bolts; the insulating gauge block is adapted to the shoulder of the iron pad for secondary adjustment.

[0015] Furthermore, the elastic pad includes a first type of elastic pad and a second type of elastic pad. The first type of elastic pad is used in curved sections where the track radius is less than a preset value, and the second type of elastic pad is used in curved sections and straight sections where the track radius is not less than the preset value.

[0016] Furthermore, through lugs are provided on both sides of the rail pad, and the through lugs are used for limiting the direction of the rail.

[0017] Furthermore, the gauge baffle has staggered frustum-shaped openings inside, and there is a height difference between the internal ribs and the side ribs of the gauge baffle; during normal use, the concave surface of the gauge baffle does not contact the outer end of the contact surface of the iron pad.

[0018] Furthermore, the elastic bar is ω-shaped, with its two sides being side limbs and its middle part being a middle limb. The frontmost points of the side limbs and the frontmost points of the middle limb are on the same plane. When fixed by the elastic bar, both the middle limb and the side limbs of the elastic bar are pressed onto the insulating gauge block.

[0019] The beneficial effects of this utility model are as follows:

[0020] This utility model optimizes and improves upon the existing WJ-8 type fastener for high-speed railway ballastless track, taking into account the operating conditions and line conditions of intercity, suburban railways, and urban rail transit. Using the shoulder-supported fastener assembly for rail transit described in this utility model, the following can be achieved:

[0021] Beneficial effects:

[0022] (1) Increase the torsional stiffness of the fasteners

[0023] By setting up elastic pads with two types of stiffness, Type I elastic pads are used on curved sections with a radius smaller than a preset value, while Type II elastic pads are used on curved sections with a radius not smaller than the preset value and on straight sections. By opening a circular hole in the middle of the elastic pad, the overall stiffness remains unchanged, but the stiffness in the middle of the pad decreases while the stiffness on both sides increases, effectively increasing the torsional stiffness of the rail and preventing the rail from tipping over.

[0024] (2) Increase the natural frequency of the spring bar

[0025] Without changing the original interface size, the existing spring bar is optimized and its structure is adjusted to increase its natural frequency.

[0026] (3) Improve the anti-loosening performance of spiral rail spikes

[0027] Without changing the original interface size and sleeve, the threads of the spiral rail spike are optimized to reduce the mating clearance between the spiral rail spike and the sleeve, increase the friction between the spiral rail spike and the sleeve, and improve the anti-loosening performance of the spiral rail spike.

[0028] (4) Increase the lateral adjustment capability of the rails and the adaptability for maintenance and repair of the fasteners.

[0029] By optimizing the structure of the iron pad and gauge baffle, and adjusting the specifications and dimensions of the insulated gauge block and gauge baffle, the lateral adjustment capability of the fastener rail has been increased from ±5mm to ±10mm. This has increased the use of the small and lightweight insulated gauge block, and the gauge baffle has been slotted to reduce weight, thus reducing the difficulty of manually carrying and replacing fastener components and making it more suitable for the increasing maintenance and repair needs of high-speed railways. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below.

[0031] Figure 1 This is a schematic diagram of the structure of this utility model;

[0032] Figure 2 This is a schematic diagram of the thread structure of the spiral rail spike of this utility model;

[0033] Figure 3 This is a schematic diagram of the structure of the elastic pad of this utility model. Figure 1 ;

[0034] Figure 4 This is a diagram showing the torsional stiffness variation of the elastic pad of this utility model;

[0035] Figure 5 This is a schematic diagram of the structure of the iron pad of this utility model. Figure 1 ;

[0036] Figure 6 This is a schematic diagram of the structure of the elastic pad of this utility model. Figure 2 ;

[0037] Figure 7 This is a schematic diagram of the structure of the iron pad of this utility model. Figure 2 ;

[0038] Figure 8-1 This is a schematic diagram of the track gauge baffle of this utility model. Figure 1 ;

[0039] Figure 8-2 This is a schematic diagram of the track gauge baffle of this utility model. Figure 2 ;

[0040] Figure 9 This is a schematic diagram of the structure of the rail underplate of this utility model;

[0041] Figure 10 This is a schematic diagram of the structure of the elastic bar of this utility model;

[0042] Figure 11 This is a frequency response curve of the elastic bar of this utility model at its natural frequency.

[0043] Explanation of the attached drawing numbers: 1-Spiral spike, 2-Flat washer, 3-Elastic strip, 4-Insulated gauge block, 5-Gauge baffle, 6-Underrail pad, 7-Iron pad, 8-Elastic pad, 9-Embedded sleeve, 10-Fine adjustment pad, 11-Height adjustment pad, 12-Rail. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. It should be understood that the described embodiments are only some embodiments of this application, not all embodiments, and these embodiments are only used to illustrate this application and not to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0045] This utility model optimizes the existing WJ-8 type fastener for high-speed railway ballastless track. The shoulder-supported fastener assembly for rail transit described in this utility model is a non-separable fastener that transmits lateral forces via a steel pad. This shoulder-supported fastener assembly for rail transit bears both vertical and lateral loads from the wheel and rail. The wheel's action on the rail head generates a vertical force V, and during turns, a lateral force L is generated. The combined effect of the vertical force V and the lateral force L produces a bending moment on the rail, causing rail torsion. Therefore, there is a risk of rail derailment when trains pass through curved sections. This utility model improves and optimizes the fastener accordingly.

[0046] like Figure 1 As shown in the figure, this utility model embodiment discloses a shoulder fastener assembly for rail transit, the structure of which includes:

[0047] The elastic clip 3, iron pad 7, and elastic pad 8 are fixed to the sleeper by the threaded engagement of the spiral spike 1 and the pre-embedded sleeve 9. A flat washer 2 is provided between the spiral spike 1 and the elastic clip 3. The iron pad 7 is above the elastic pad 8. The elastic pad 8 has a round hole in the middle and bolt holes at both ends. The iron pad 7 has a shoulder and bolt holes. The elastic pad 8 and the iron pad 7 are limited by the bolt holes. A rail underplate 6 is provided above the iron pad 7. The rail underplate 6 is in direct contact with the rail 12. An insulating gauge block 4 is pressed and limited on the rail 12. A gauge baffle 5 is placed on the other side of the spiral spike 1. The elastic clip 3 is pressed on the gauge baffle 5 and the insulating gauge block 4. A fine-adjustment shim 10 is provided between the iron pad 7 and the rail underplate 6. A height adjustment shim 11 is provided between the elastic pad 8 and the sleeper.

[0048] like Figure 2 As shown, the top of the thread of the spiral rail spike 1 in this embodiment is chamfered.

[0049] In this embodiment, the spacing L between the threads of the spiral stud 1 is 12.5 mm; an R1 chamfer is added to the top of the thread, R1 is 1 mm; the angle between the top surface of the thread and the horizontal plane is 45 degrees, the angle between the bottom surface of the thread and the horizontal plane is 15 degrees, the top diameter of the thread R3 is 3 mm, the bottom diameter of the thread R2 is 1.5 mm, and the thickness of the thread b is 4 mm.

[0050] The optimized spiral rail spike of this invention is less prone to thread damage during production. It also increases thread thickness, reduces the clearance between the spiral rail spike and the embedded sleeve, improves the fit between them, increases friction, and enhances the spike's resistance to loosening.

[0051] like Figure 3 As shown, in this embodiment, a circular hole with a diameter of 40-80mm is provided in the middle of the elastic pad 8. The elasticity of the rail transit fastener assembly with shoulder guard described in this utility model is mainly provided by the elastic pad 8 under the iron pad 7. Therefore, the torsional stiffness of the fastener (the reaction torque when the rail generates a unit angle of rotation) mainly comes from the anti-overturning properties of the elastic pad under the iron pad and the clamping of the elastic strip. Therefore, the formula for calculating the torsional stiffness can be derived as follows:

[0052]

[0053] Where, k t For torsional stiffness, k pt k is the torsional stiffness of the elastic pad. ct For the torsional stiffness of the elastic bar, For the stiffness of the elastic pad, k c denoted as b, where b is the stiffness of the front end of the spring bar, and d is the length of the elastic pad under the iron pad.

[0054] In this embodiment, when an elastic pad with high static stiffness (35±5kN / mm) is used, the torsional stiffness is reduced from 1.61×10 5 The N·m / rad increased to 2.32 × 10⁻⁶. 5 The torsional stiffness increased significantly by 44.1% (N·m / rad).

[0055] In this embodiment, the structure of the elastic pad 8 is optimized by adjusting the stiffness distribution along the length of the iron pad, thereby increasing the torsional stiffness of the fastener. In this embodiment, a circular hole with a diameter of 40-80mm is opened in the middle of the elastic pad 8, reducing the stiffness in the middle and increasing the stiffness on both sides. At this point, the stiffness of the elastic pad exhibits a non-linear change along its length. Using the above measures can effectively increase the torsional stiffness of the rail and prevent rail overturning.

[0056] In this embodiment, the bolt holes of the elastic pad 8 can be set as U-shaped grooves to increase the left and right position adjustment capability of the fastener and avoid the pad being crushed or cracked due to the thin edge of the bolt hole.

[0057] Additionally, such as Figure 6 As shown, the bolt holes of the elastic pad in this embodiment can also be configured as extended ends. Reducing the length of the elastic pad by 5mm increases the lateral adjustment capability of the fastener, and a protrusion is provided at the thinnest point of the bolt hole edge for local reinforcement. The thinnest point of the bolt hole in the existing elastic pad design is 6.8mm, while the thinnest point of the bolt hole in this utility model is 14.4mm, an increase of nearly 112%, effectively avoiding permanent compression deformation or even damage that easily occurs at the thinnest point of the bolt hole edge during the use of the original elastic pad.

[0058] In this embodiment, the elastic pad 8 includes a first type of elastic pad and a second type of elastic pad. The first type of elastic pad is used on curved sections with a track radius smaller than a preset value, while the second type of elastic pad is used on curved sections and straight sections with a track radius not less than the preset value. Specifically, to improve the quality of the elastic pad, reduce the production dispersion of the elastic pad stiffness, and improve the stability of the rail on small-radius curved sections, two static stiffness specifications are proposed for the elastic pad: 30-40 kN / mm for the first type of elastic pad and 20-26 kN / mm for the second type of elastic pad. The first type of elastic pad with a stiffness of 30-40 kN / mm is used on curved sections with a radius R < 800 m; the second type of elastic pad with a stiffness of 20-26 kN / mm is used on curved sections with a radius R ≥ 800 m and straight sections.

[0059] like Figure 4 As shown in the figure, this embodiment illustrates the torsional situation when an 80mm diameter circular hole is provided in the center of the elastic pad. With the circular hole in the center of the elastic pad, the calculated static stiffness of the elastic pad is 35kN / mm. After adjusting the stiffness of the elastic pad from a uniform distribution to a non-linear distribution, the torsional stiffness of the fastener increases from 2.32 × 10⁻⁶ kN / mm. 5 The N·m / rad increased to 2.52 × 10⁻⁶. 5 The torsional stiffness increased by 8.6% (N·m / rad). By combining measures to increase the static stiffness of the elastic pad from 23±3 kN / mm to 35±5 kN / mm and the non-linear stiffness distribution after structural optimization, the torsional stiffness of the fastener can be increased from 1.61 × 10⁻⁶ kN / mm. 5 The N·m / rad increased to 2.52 × 10⁻⁶. 5 The torsional stiffness increased by a cumulative 56.5% in N·m / rad.

[0060] like Figure 5As shown, in this embodiment, the rail bearing surface of the iron pad 7 is not provided with a limiting boss, and the four limiting bosses around the rail bearing surface of the iron pad are eliminated to avoid problems such as aging and cracking of the rubber pad around the boss. The iron pad in this embodiment is provided with a shoulder and bolt holes. In this embodiment, the bolt holes of the iron pad correspond to the bolt holes of the elastic pad.

[0061] Specifically, the distance between the two shoulders of the iron pad is increased from 169mm to 170-172mm, increasing the lateral adjustment of the rail between the shoulders of the iron pad, from ±2mm to ±3mm.

[0062] In this embodiment, the bolt holes of the iron pad can be set as U-shaped grooves to increase the lateral adjustment capability of the fastener, avoid thin-walled structures on both sides of the iron pad, and prevent manufacturing quality defects.

[0063] Additionally, such as Figure 7 As shown, in this embodiment, the bolt holes of the iron pad can also be designed with extended ends to avoid thin-walled structures on both sides of the iron pad. The thinnest part of the bolt hole groove of the iron pad in this embodiment is 16.9mm, which is 80% larger than the original design, correspondingly reducing stress concentration by 80% and effectively avoiding stress concentration and manufacturing quality defects. At the same time, in order to increase the lateral adjustment range of the rail, the length of the iron pad is reduced by 5mm.

[0064] In this embodiment of the utility model, the iron pad with the bolt hole set as a U-shaped groove matches the elastic pad with the bolt hole set as a U-shaped groove, and the iron pad with the bolt hole set as an end extension matches the elastic pad with the bolt hole set as an end extension.

[0065] like Figure 8-1 and Figure 8-2 As shown, in this embodiment, the gauge baffle 5 has staggered frustum-shaped openings on one side, and there is a height difference between the internal ribs and the side ribs of the gauge baffle. During normal use, the concave surface of the gauge baffle 5 does not contact the outer side of the iron pad 7. The staggered frustum-shaped openings inside the gauge baffle 5 ensure a large contact area between the gauge baffle and the shoulder, low pressure, and do not affect the lateral and vertical load-bearing capacity of the gauge baffle, while preventing rainwater from entering. The openings also facilitate mold separation after injection molding of the glass fiber reinforced polyamide material. The 4mm height difference between the internal ribs and the side ribs of the gauge baffle allows for free drainage during rainfall, ensuring its insulation. Each gauge block of this fastener weighs approximately 50g, and each gauge baffle weighs approximately 500g. The increased adjustment range and the combined use of insulated gauge blocks effectively reduce the transportation and time costs required for left-right adjustment of the rails during track maintenance.

[0066] The WJ-8 gauge baffle comes in five specifications: No. 2, No. 4, No. 7, No. 10, and No. 12. No. 7 is used normally. This optimization increases the lateral adjustment range of the rails and reduces the number of gauge baffle specifications, facilitating on-site maintenance. The optimized gauge baffle retains only three specifications: No. 2, No. 9, and No. 16, with No. 9 used normally. The contact surface of the gauge baffle's iron pad has been specially designed to complement the iron pad structure. Under normal use, the concave surface of the gauge baffle's contact surface does not contact the two ends of the iron pad, meaning it does not transmit lateral force. The lateral adjustment capability of the gauge baffle has been optimized from ±3mm to ±7mm, increasing the gauge adjustment capability of the fasteners by 133%.

[0067] The contact point between the gauge baffle 5 and the elastic clip 3 is set with a groove of 8mm radius, slightly higher than the radius of the elastic clip 3 itself by 7mm. A 1mm straight section is provided inside the groove. The rear width of the groove is 34mm, and the front width is 20mm, facilitating the installation and positioning of the elastic clip 3. When adjusting the left and right position of the rail, replacing the gauge baffle and gauge block will not affect the fastening position of the elastic clip 3, as both are located at the highest point of the arc of the middle limb of the elastic clip 3, ensuring no additional bending moment is generated, thus affecting the bolt service life and the stress state of the elastic clip.

[0068] The gauge baffle is made of a high-polymer material (glass fiber reinforced polyamide 66), which allows for soft contact between the elastic clip's clamping end and the gauge block. This prevents the elastic clip from breaking due to longitudinal rail movement causing it to jam. It also ensures that the clamping section of the elastic clip is of approximately consistent length, reducing the impact of dimensional errors on its natural frequency. Furthermore, this design allows the elastic clip's resonant frequency to reach above 800Hz, avoiding the excitation frequencies below 750Hz commonly found in high-speed, intercity, and urban railway lines due to rail corrugation and polygonal wheel shapes.

[0069] In this embodiment, in order to increase the adjustment amount of the insulating gauge block, the size of the insulating gauge block 4 clamping the rail is adjusted from the original 20mm to 25mm, the length of the insulating gauge block 4 is extended from the original 110mm to 120mm, the mass of the spring clip clamping end mass block is increased, and the natural frequency of the spring clip is increased. The length of the contact surface between the insulating gauge block 4 and the bottom of the rail remains unchanged, and the extended parts at both ends are provided with upturned corners so as not to contact the bottom of the rail.

[0070] This invention has two settings for adjusting the left and right sides of the rails: when the adjustment range of a single rail is within ±3mm, adjustment can be achieved simply by replacing the insulating gauge block with one of different thicknesses. It is lightweight, compact, and easy to carry and replace. When the adjustment range of a single rail is between ±4mm and ±10mm, adjustment is achieved by simultaneously replacing the insulating gauge block and the gauge baffle.

[0071] By setting different thicknesses for the insulated gauge blocks perpendicular to the rail direction, convenient adjustments of ±3mm to the lateral position of the rail can be achieved. Three gauge block specifications (No. 2, No. 9, and No. 16) are available, and by adjusting the distance between the contact surface of the gauge block and the iron pad and the horizontal contact point of the shoulder of the gauge block and the iron pad, the gauge blocks can be adjusted. Changing the gauge blocks allows for lateral movement of the iron pad and the rail, thereby adjusting the gauge by ±7mm. Combining the insulated gauge blocks and gauge blocks, adjustments of ±10mm to the lateral position of the rail on one side and ±20mm to the gauge can be achieved, with adjustment increments of 0.5mm, resulting in higher precision.

[0072] This utility model optimizes the structure of the iron pad 7 and the gauge baffle 5, increases the specifications of the insulating gauge block 4 and the gauge baffle 5, increases the left and right position adjustment capability of the fastener rail from the original ±5mm to ±10mm, and reduces the adjustment increment from 1mm to 0.5mm. It also increases the use of the small and lightweight insulating gauge block, and performs slotted weight reduction treatment on the gauge baffle, reducing the difficulty of manually carrying and replacing fastener components, and better adapting to the increasing maintenance and repair needs of high-speed railways.

[0073] like Figure 9 As shown, in this embodiment, the rail pad 6 is provided with through ears on both sides, which are used to limit the direction of the rail.

[0074] Specifically, the rail pad is lengthened and the side lugs on both sides are extended. The original design side lug length was 115mm, and after the length is increased and the side lugs are extended, the length is 165mm, an increase of 50mm. This improves the longitudinal positioning capability of the rail pad along the rail by approximately 43%. In this embodiment, the rail pads are available in six thicknesses: 2mm, 4mm, 6mm, 8mm, 10mm, and 12mm. These are used in conjunction with 0.5mm and 1mm thick micro-adjustment pads for rail height adjustment, reducing the rail height adjustment increment from 1.0mm to 0.5mm, a reduction of 50%.

[0075] When the rail causes a 1mm displacement in the rail pad, the maximum stress on the side lugs of the rail pad in the prior art is 4.9MPa, while the maximum stress after the side lugs of this invention are connected on both sides is 3.5MPa, allowing the side lugs to withstand greater longitudinal displacement. When the rubber material strength is 12.5MPa, the side lugs of the rail pad in the prior art can only withstand a deformation of 2.6mm, while this invention can withstand a deformation of 3.6mm, increasing the longitudinal restraint capacity by 38.5%.

[0076] like Figure 10As shown, this embodiment also presents structural optimizations for the spring clip 3, where h1 is the spring range, h2 is the lateral limb arch height, h3 is the middle limb arch height, b is the width at the pin placement point, L1 is the width of both limbs, L2 is the middle width, L3 is the distance between the clamping ends, L4 is the maximum width, and L5 is the contact length of the straight section of the clamping limb. While maintaining the original interface dimensions, the existing W1-type spring clip is optimized to improve its natural frequency. The lateral limb arch height is reduced from 44mm to 30mm; the straight section length of the clamping limb is increased from 30mm to over 35mm; and the radius of the tail end arc is increased from 25mm to 30mm. The spring clip 3 of this invention still uses 60Si2Mn spring steel as its raw material. Compared with existing spring clips, the spring range and clamping force of this invention are comparable, but the stress is reduced, and the natural frequency is significantly improved. The natural frequency of this invention's spring clip is approximately 850Hz, which can effectively avoid resonance fracture caused by cyclic wear of the wheel and rail.

[0077] In this embodiment, the height difference between the bottom surface of the front end of the middle limb and the bottom surface of the front end of the side limb of the elastic clip 3 is used as the elastic clip's range, which is 14mm. Fatigue performance testing of the elastic clip meets the technical requirements of a static assembly displacement of 14mm for the side limbs, a dynamic fatigue amplitude of -2.0 to +0.5mm, no breakage after 5 million fatigue loading cycles, and residual deformation of the range not exceeding 1mm. The elastic clip is placed at the normal installation angle, a 50kN vertical load is applied to the fastening position of the middle limb and stabilized for 5 seconds before being unloaded. This is repeated 3 times. The change in height (i.e., residual deformation) of the upper surface of the middle limb from the clamping surface is not higher than 1mm, while the residual deformation of other existing high-speed railway fasteners is around 2mm, thus improving the elastic clip's performance retention capability.

[0078] The foremost points of the side and middle limbs of the elastic clip are on the same plane, ensuring that after the clip is tightened, both the middle and side limbs can be pressed against the gauge block. This provides secondary clamping stiffness and additional clamping force in the event of rail overturning. The secondary stiffness is designed to be more than five times the primary stiffness, enhancing the anti-overturning capability of the fastening system and improving train operation safety when the lateral force between the wheel and rail is excessive.

[0079] like Figure 11 As shown, the difference in natural frequencies between the elastic clip 3 of this utility model and the WJ-8 type fastener elastic clip of high-speed railway ballastless track under standard installation conditions was tested using the frequency response method. The first natural frequency of the WJ-8 type fastener elastic clip is 652Hz, while the first natural frequency of the elastic clip of this utility model is increased to 856Hz, which is higher than the excitation frequency of less than 750Hz commonly found in the periodic wear of wheel and rail in rail transit such as high-speed, intercity and urban railways. This can effectively avoid resonance fracture caused by periodic wear of wheel and rail.

[0080] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A shoulder stop fastener assembly for rail transportation, characterized in that, include: The elastic clip, iron pad, and elastic pad are fixed to the sleeper by the threaded engagement of the spiral spike and the pre-embedded sleeve. A flat washer is provided between the spiral spike and the elastic clip. The iron pad is on the upper part of the elastic pad. A round hole is provided in the middle of the elastic pad. Bolt holes are provided at both ends of the elastic pad. The iron pad is provided with a shoulder and bolt holes. The elastic pad and the iron pad are limited by the bolt holes. A rail pad is provided on the upper part of the iron pad plate. The rail pad is in direct contact with the rail. An insulating gauge block is pressed onto the rail. A gauge baffle is placed on the other side of the spiral spike. The elastic bar is pressed onto the gauge baffle and the insulating gauge block. A fine-adjustment shim is provided between the iron pad and the rail pad, and a height adjustment shim is provided between the elastic pad and the sleeper.

2. A shoulder stop fastener assembly for rail transportation as claimed in claim 1 wherein, The top of the threads of the spiral rail spike is chamfered.

3. A shoulder stop fastener assembly for rail transportation as claimed in claim 1 wherein, The rail bearing surface of the iron pad is not provided with a limiting boss, and the bolt holes of the iron pad are provided with U-shaped grooves or extended at both ends.

4. A shoulder stop fastener assembly for rail transportation as claimed in claim 3 wherein, The bolt holes of the elastic pad are configured as U-shaped grooves or extended ends.

5. A shoulder stop fastener assembly for rail transportation as claimed in claim 4 wherein, When the bolt holes of the iron pad are U-shaped grooves, the lateral fit position is adjusted by fixing the iron pad with the spiral rail spike bolts through the U-shaped grooves of the iron pad; the insulating gauge block is adapted to the shoulder of the iron pad for secondary adjustment.

6. A shoulder stop fastener assembly for rail transportation as defined in claim 1, wherein, The elastic pad includes a first type of elastic pad and a second type of elastic pad. The first type of elastic pad is used on curved sections with a track radius less than a preset value, and the second type of elastic pad is used on curved sections and straight sections with a track radius not less than the preset value.

7. A shoulder stop fastener assembly for rail transportation as defined in claim 1, wherein, The track pad is provided with through lugs on both sides, which are used to limit the track direction.

8. A shoulder stop fastener assembly for rail transportation as defined in claim 1, wherein, The gauge baffle has staggered frustum-shaped openings inside, and there is a height difference between the internal ribs and the side ribs of the gauge baffle; during normal use, the concave surface of the contact surface of the gauge baffle does not contact the outer end of the iron pad.

9. A shoulder stop fastener assembly for rail transportation as defined in claim 1, wherein, The elastic bar is ω-shaped, with its two sides being side limbs and its middle part being a central limb. The frontmost points of the side limbs and the frontmost points of the central limb are on the same plane. When the elastic bar is fixed, both the central and side limbs of the elastic bar are pressed onto the insulating gauge block.

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