Urban rail transit small resistance fastener system

Abstract

The utility model relates to the field of rail transit engineering technology, concretely relates to a small resistance fastener system for urban rail transit, including iron fender, insulating track gauge block, T type bolt, small resistance elastic strip and composite fender, the insulating track gauge block sets up the both sides at the steel rail, the composite fender sets up below the steel rail, the small resistance elastic strip is fixed on the iron fender through the nut and is compacted the insulating track gauge block by T type bolt, the composite fender includes rubber plate body and high molecular resistance reduction layer, the high molecular resistance reduction layer sets up the upper surface of rubber plate body and both constitute an integrity. The utility model has the advantages of: realizing fender on the basis of guaranteeing structural strength, possessing excellent small resistance performance, effectively buffering train impact, reducing track fastener system stress, prolonging track maintenance cycle.

Description

Technical Field

[0001] This utility model relates to the field of rail transit engineering technology, specifically to a low-resistance fastener system for urban rail transit. Background Technology

[0002] In the process of promoting urbanization, and to address the increasingly serious urban public transportation problems, my country has begun to vigorously develop urban rail transit, primarily subways. Fastening systems are essential for ensuring a reliable connection between the rails and the concrete foundation, guaranteeing both the reliability and stability of the connection while providing the rails with both elasticity and rigidity. Furthermore, the rail transit network includes not only underground long-resistance lines but also some elevated low-resistance lines; therefore, it is necessary to research suitable low-resistance composite pads to meet the requirements of different lines.

[0003] Composite pads are a crucial component of low-resistance fasteners, requiring not only good elasticity but also reduced running resistance. Currently, common composite pads for low-resistance fasteners employ a rubber-stainless steel composite design. The rubber layer serves as the "elastic layer," primarily for vibration and noise reduction; the stainless steel plate acts as the "drag-reducing layer," directly contacting the rail's underside to reduce friction between the rail and the pad. The stainless steel plate features a double-plane flat structure. The "elastic layer" and "drag-reducing layer" are bonded together via hot vulcanization.

[0004] However, the main disadvantages of the "rubber plus stainless steel" composite pad during use are twofold: 1) The stainless steel plate has poor corrosion resistance during use, and it is easy to reduce or even lose the anti-friction layer's effectiveness after rusting; 2) The stainless steel plate and rubber plate are prone to bending deformation during the hot vulcanization process, which is not conducive to product size control; 3) The product has poor overall stiffness adjustment capability and cannot meet design requirements. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the existing technology by providing a low-resistance fastener system for urban rail transit. By designing a combination structure of low-resistance spring clips and composite pads, the fastener can be applied to low-resistance sections and ensures that the spring clip clamping point is reasonably positioned in low-resistance, small-radius curve sections. This allows the pads to achieve excellent low-resistance performance while ensuring structural strength, effectively buffering train impacts, reducing stress on the track fastener system, and extending track maintenance cycles.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] A low-resistance fastening system for urban rail transit, used to fix rails to an underlying foundation, is characterized by comprising: an iron pad, an insulating gauge block, a T-bolt, a low-resistance spring strip, and a composite pad. The insulating gauge block is disposed on both sides of the rail, and the composite pad is disposed below the rail. The T-bolt, through nuts, fixes the low-resistance spring strip onto the iron pad and presses it against the insulating gauge block. The composite pad comprises a rubber sheet body and a polymer drag-reducing layer, the polymer drag-reducing layer being disposed on the upper surface of the rubber sheet body and the two forming an integral unit.

[0008] The upper and lower surfaces of the rubber sheet are respectively provided with a number of grooves, and the positions of the grooves on the upper surface of the rubber sheet are staggered with the positions of the grooves on the lower surface of the rubber sheet.

[0009] The rubber sheet is provided with hanging ears at both the front and rear ends, and the rubber sheet is fastened to both sides of the iron pad through the hanging ears.

[0010] The iron pad is fixedly connected to the nylon sleeve embedded in the foundation by anchor bolts.

[0011] A toothed washer is provided between the anchor bolt and the iron pad, and the toothed surface of the toothed washer and the surface of the iron pad form a toothed fit; a heavy-duty spring washer is provided between the anchor bolt and the toothed washer.

[0012] An insulating buffer pad is provided below the iron pad.

[0013] An adjustable height pad is provided between the iron pad and the insulating buffer pad.

[0014] A rail-mounted height adjustment pad is installed below the composite pad.

[0015] The advantages of this utility model are:

[0016] 1) Low resistance characteristics: The optimized fasteners meet the longitudinal resistance requirements of 4kN for some urban subways by replacing the elastic clips, composite pads and insulated gauge blocks. The low friction coefficient of the composite pad drag-reducing layer makes the composite pad have less resistance when the train is running, which can reduce the additional force of the fasteners on the track structure, adapt to bridge structures and curved sections, reduce train running energy consumption and improve the operating efficiency of the track system.

[0017] 2) High elasticity and vibration absorption performance: The high elasticity and resistance to compression deformation of the rubber layer can effectively buffer the vibration and impact during train operation, reduce the dynamic stress of the track structure, and improve the stability and service life of the track system. At the same time, the vibration absorption performance of the rubber layer can also effectively reduce the noise generated during train operation, improve the urban environment, and ensure the safety and comfort of train operation.

[0018] 3) Good wear resistance and corrosion resistance: The reasonable combination of drag-reducing layer and rubber layer and the optimization of material formula make the composite pad have good wear resistance and corrosion resistance, which can adapt to the complex operating environment of urban rail transit, reduce the replacement frequency of pads and reduce maintenance costs. Attached Figure Description

[0019] Figure 1 This is a top view of the present invention;

[0020] Figure 2 for Figure 1 Sectional view along line AA in the middle;

[0021] Figure 3 This is a cross-sectional schematic diagram of the composite pad in this utility model;

[0022] Figure 4 This is a schematic diagram of the composite pad in this utility model. Detailed Implementation

[0023] The features of this utility model and other related features will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate the understanding of those skilled in the art:

[0024] like Figure 1-4 As shown in the figure, numbers 1-18 represent: T-bolt 1, nut 2, flat washer 3, low-resistance spring strip 4, composite pad 5, iron pad 6, insulating buffer pad 7, insulating gauge block 8, insulating gauge block 9, anchor bolt 10, heavy-duty spring washer 11, toothed pad 12, nylon sleeve 13, rail height adjustment pad 14, iron pad lower height adjustment pad 15, rubber plate 16, polymer drag-reducing layer 17, and lug 18.

[0025] Example: Figures 1 to 4 As shown in the figure, in this embodiment, the low-resistance composite pad and fasteners for urban rail transit are used to fix the rails to the foundation below.

[0026] Specifically, combined Figure 1 and Figure 2 As shown, the structure includes an iron pad 6, an insulated gauge block 8, an insulated gauge block 9, T-bolts 1, a low-resistance spring strip 4, and a composite pad 5. The insulated gauge blocks 8 and 9 are respectively positioned on both sides of the rail to fix its position. The composite pad 5 is positioned below the rail. Each insulated gauge block 8 and 9 has a corresponding T-bolt 1. The T-bolts 1, through nuts 2 and flat washers 3, fix the low-resistance spring strip 4 onto the iron pad 6 and press it against the insulated gauge blocks 8 and 9, thus achieving fixation.

[0027] In this embodiment, the low-resistance spring clip 4 has a standard material diameter of 13mm and a spring travel of 9mm, which can be adapted to the DTⅢ2-A iron pad spring clip base, meeting the installation requirements during maximum gauge adjustment. The clamping force meets the requirements, and the maximum stress is similar to other low-resistance spring clips. To adapt to the low-resistance spring clip 4, the clamping end length of the insulating gauge block 8 and insulating gauge block 9 is increased by 6mm. The optimized insulating gauge blocks all meet the installation requirements of the low-resistance spring clip 4 under both maximum and minimum gauge adjustments.

[0028] like Figure 3 As shown, the composite pad 5 includes a rubber sheet 16 and a polymer drag-reducing layer 17, which is disposed on the upper surface of the rubber sheet 16 and the two are integral.

[0029] In this embodiment, as Figure 3 As shown, the composite pad 5 is a rectangular plate. The rubber plate 16 adopts a double-grooved design, with seven grooves on the upper surface and six grooves on the lower surface. The grooves are U-shaped, with a smaller bottom and a larger top. The width of the lower end of the groove is 5mm, the width of the upper end is 6mm, and the depth is 4.5mm. The spacing between each groove is 19mm, and they are evenly distributed on the upper and lower surfaces of the rubber plate 16. Each lower groove is located between two adjacent upper grooves. The polymer drag-reducing layer is 1.2mm thick, adopts a double-plane flat plate structure, has a smooth surface, and its dimensions are consistent with the upper surface of the rubber plate. It covers the upper surface of the rubber plate and is integrated with the rubber plate through processing technology.

[0030] Furthermore, the rubber plate 16 is made of natural or synthetic rubber, providing excellent elasticity, cold resistance, wear resistance, and aging resistance, ensuring the stability of the rubber layer under long-term complex environments, effectively buffering train impacts and reducing vibration transmission; the grooves on the rubber plate 16 further enhance its performance. The polymer drag-reducing layer 17 uses high-strength, wear-resistant polyamide 66 (PA66) as the matrix material, reinforced with glass fiber, with a glass fiber content of 30%-35%, to improve the tensile strength and flexural modulus of the drag-reducing plate, enabling it to withstand the enormous pressure transmitted from the rail and the dynamic load of the train, ensuring the structural integrity of the pad. The surface of the polymer drag-reducing layer 17 is smooth, reducing friction and meeting the low-resistance requirements.

[0031] like Figure 4 As shown, lugs 18 are provided at the front and rear ends of the rubber plate 16, and the lugs 18 at both ends can play a limiting role. During the installation process, the lugs 18 can tightly fasten the two sides of the iron pad 6, thereby accurately ensuring the installation position of the composite pad 5, effectively preventing longitudinal displacement or slippage of the composite pad 5, and improving the stability of the rail pad component.

[0032] Combination Figure 1 and Figure 2 As shown, the iron pad 6 is fixedly connected to the nylon sleeve 13 embedded in the foundation by anchor bolts 10, thereby achieving a fixed connection between the iron pad 6 and the foundation. A toothed pad 12 is provided between the anchor bolt 10 and the iron pad 6. The toothed surface of the toothed pad 12 forms a toothed fit with the surface of the iron pad 6, improving the limiting effect between the two. A heavy-duty spring washer 11 is provided between the anchor bolt 10 and the toothed pad 12.

[0033] like Figure 2 As shown, an insulating buffer pad 7 is provided below the iron pad 6 in order to provide insulation and cushioning.

[0034] like Figure 2 As shown, when it is necessary to adjust the height of the rails, this can be achieved in two ways, and one or both methods can be used simultaneously:

[0035] 1) An iron pad lowering pad 15 is provided between the iron pad 6 and the insulating buffer pad 7.

[0036] 2) A rail height adjustment pad 14 is installed between the composite pad 5 and the iron pad 6.

[0037] In the specific implementation of this embodiment:

[0038] Composite pad 5 includes the following processing steps:

[0039] 1) Fabricate a polymer drag-reducing layer 17 that conforms to the dimensions of the composite pad 5: Cut the nylon sheet into pieces according to the external dimensions of the composite pad 5.

[0040] 2) Fabricate a rubber sheet body 16 that conforms to the dimensions of composite pad 5:

[0041] S1. Ingredients: Ingredients are prepared according to the composition formula of rubber sheet 16;

[0042] S2. Rubber mixing: The raw materials prepared in the batching step are added to the rubber mixing machine and mixed to produce raw rubber;

[0043] S3. Cutting: Cut the raw rubber into pieces according to the outer dimensions of the composite pad 5 to make raw rubber sheets;

[0044] S4. Vulcanization molding: Place the raw rubber sheet into the vulcanizing machine, close the mold, and vulcanize to form the final product;

[0045] S5. Trimming: Trim the rough edges off the vulcanized product.

[0046] 3) Apply a transition adhesive layer to the contact surface between the polymer drag-reducing layer 17 and the rubber sheet 16 to bond the drag-reducing layer to the upper surface of the rubber sheet, thus completing the processing of the composite pad.

[0047] When applied, the static stiffness of the composite pad 5 processed according to the above method is tested to be 30±5kN / mm, the dynamic-to-static stiffness ratio of the composite pad 5 is not greater than 1.4, and it should not crack after 3 million fatigue tests, and the static stiffness change rate should not exceed 10%.

[0048] Based on this, the composite pad 5 in this embodiment is suitable for elastically separated fasteners for urban rail transit. It is usually laid in areas where the fastener resistance is required to be about 4kN, which meets the application requirements of fasteners in low-resistance areas, increases the comfort and stability of train operation, and can better meet the development needs of urban rail transit.

[0049] Although the above embodiments have described the concept and embodiments of the present invention in detail with reference to the accompanying drawings, those skilled in the art will recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, and therefore will not be elaborated here.

Claims

1. A low-resistance fastening system for urban rail transit, used to fix rails to an underlying foundation, characterized in that: The system includes an iron pad, an insulating gauge block, T-bolts, a low-resistance spring clip, and a composite pad. The insulating gauge blocks are disposed on both sides of the rail, and the composite pad is disposed below the rail. The T-bolts, with nuts, fix the low-resistance spring clip onto the iron pad and press it against the insulating gauge block. The composite pad comprises a rubber sheet and a polymer drag-reducing layer, with the polymer drag-reducing layer disposed on the upper surface of the rubber sheet and the two forming an integral unit. The upper and lower surfaces of the rubber sheet are respectively provided with a number of grooves, and the positions of the grooves on the upper surface of the rubber sheet are staggered with the positions of the grooves on the lower surface of the rubber sheet.

2. The low-resistance fastener system for urban rail transit according to claim 1, characterized in that: The rubber sheet is provided with hanging ears at both the front and rear ends, and the rubber sheet is fastened to both sides of the iron pad through the hanging ears.

3. The low-resistance fastener system for urban rail transit according to claim 1, characterized in that: The iron pad is fixedly connected to the nylon sleeve embedded in the foundation by anchor bolts.

4. A low-resistance fastener system for urban rail transit according to claim 3, characterized in that: A toothed washer is provided between the anchor bolt and the iron pad, and the toothed surface of the toothed washer and the surface of the iron pad form a toothed fit; a heavy-duty spring washer is provided between the anchor bolt and the toothed washer.

5. A low-resistance fastener system for urban rail transit according to claim 1, characterized in that: An insulating buffer pad is provided below the iron pad.

6. A low-resistance fastener system for urban rail transit according to claim 5, characterized in that: An adjustable height pad is provided between the iron pad and the insulating buffer pad.

7. A low-resistance fastener system for urban rail transit according to claim 1, characterized in that: A rail-mounted height adjustment pad is installed below the composite pad.

Images