A lateral dynamic loading device for high-frequency stiffness testing of railway fasteners

Abstract

The present invention relates to a lateral dynamic loading device for high-frequency stiffness testing of railway fasteners, which includes a dynamic excitation system (2), a fastener system to be measured (3), and a fastener installation tooling (4). The device also includes a lateral excitation tooling (1) and a static loading system (5). The lateral excitation tooling (1) is arranged between the static loading system (5) and the fastener system to be measured (3). Under the combined action of static preloading force and dynamic excitation, the lateral excitation tooling (1) drives the fastener system to be measured (3) to generate high-frequency and lateral reciprocating motion. The lateral force range is 0 - 3000 N, and the frequency range is 0 - 2000 Hz, truly simulating the dynamic stiffness change characteristics of the railway fastener system under the action of wheel-rail coupling lateral high-frequency excitation in the curve section. Compared with the prior art, the device of the present invention ensures lateral high-frequency reciprocating motion of lateral excitation under vertical preloading, has a reliable structural design, and strong practicability and operability.

Description

Technical Field

[0001] The present invention relates to the field of rail transit, and provides a lateral dynamic loading device for high-frequency stiffness testing of railway fasteners. Background Art

[0002] In the field of rail transit, the fastener system is the most important component for connecting the rail and the sleeper. Its function is to fix the rail on the sleeper, maintain the gauge and prevent the longitudinal and lateral movement of the rail relative to the sleeper. The commonly used fasteners for urban rail transit are designed for vibration reduction, and the elastic pad of the fastener system is a two-layer design. As the operation time of the line increases, the elastic pad ages under long-term conditions of damp and dark or exposure to the sun on elevated lines, and the stiffness of the fastener system increases. At the same time, with the continuous increase of the urban population, in order to further improve the transport capacity, the departure interval and running speed of the subway company have been increased to varying degrees. At the same time, due to the change of the stiffness of the fastener system, the environmental protection pressure of urban rail transit has been further increased. The commonly used fasteners for domestic high-speed railways are W300, WJ-8, WJ-7 and SFC fasteners, etc., and the designs are all of the structural forms with an under-rail pad and an under-board pad. Due to the characteristics of high axle load, high speed and high traffic density of high-speed railway trains, combined with the open-air use environment of high-speed railway fasteners, the aging rate of the elastic layer rubber is relatively high, which increases the fastener stiffness, continuously aggravates the wheel-rail wear, and the noise pollution along the railway is becoming increasingly serious.

[0003] Regarding the research on the stiffness of railway fastener systems, domestic and foreign manufacturers mainly refer to the series of standards BS EN13146-9:2009 and TB / T3395-2015 for the stiffness testing of single-piece pads and assembled fastener systems. However, the dynamic stiffness testing requirements for railway fasteners in both standards are low-frequency, basically in the range of 3 - 10 Hz. However, according to the research results on the mechanism of vibration noise and damage of track components in existing subways or high-speed railways, the excitation frequency or resonance damage frequency generated after railway wheel-rail wear is generally above 400 Hz, and even exceeds 1000 Hz. Especially in small-radius curve sections, the wear amount of the low rail is about the same as that of the high rail, and the lateral wear is further increased. However, there is no written report at home and abroad on the change law and trend of the fastener stiffness under the action of this excitation frequency of the track system. Exploring and researching the change law of fastener stiffness under the high-frequency excitation characteristics of wheel-rail has great reference significance for studying the mechanism and control of wheel-rail noise and damage of track system components.

[0004] The international standard ISO10846-5 proposes a set of test calculation methods for elastic elements using the excitation point measurement method. With the reduction of the stiffness of urban rail transit fasteners, the method in the standard has certain limitations. Because as the frequency range of the measured component increases, the equivalent vibration mass inertia stiffness ω of the test system 2 m 1 for the measured dynamic stiffness k of the excitation point 11The contribution also increases. At the same time, if the low stiffness characteristic of the elastic unit to be measured, the equivalent support stiffness k of the test system i is no longer negligible, and only a set of test simulation devices is proposed. The vertical schematic device is relatively simple and easy to implement, while the lateral excitation device uses multiple sets of lateral sliding bearings and limit bearings arranged on the loading plate. Under the pre-static load, the lateral friction force of the device is large, and the lateral excitation frequency is concentrated in the low frequency range. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned existing technologies and provide a lateral dynamic loading device for high-frequency stiffness testing of railway fasteners, which can perform high-frequency lateral dynamic stiffness testing of railway fasteners, and the dynamic testing frequency range can reach 0 - 2000 Hz.

[0006] The purpose of the present invention can be achieved by the following technical solutions: A lateral dynamic loading device for high-frequency stiffness testing of railway fasteners, including a dynamic excitation system, a fastener system to be measured, and a fastener installation tooling. It is characterized in that the device further includes a lateral excitation tooling and a static loading system. The lateral excitation tooling is arranged between the static loading system and the fastener system to be measured. Under the coupled action of the static preloading force and the dynamic excitation, the lateral excitation tooling drives the fastener system to be measured to generate high-frequency and lateral reciprocating motion, with a lateral force range of 0 - 3000 N and a frequency range of 0 - 2000 Hz, truly simulating the dynamic stiffness change characteristics of the railway fastener system under the action of high-frequency lateral excitation of wheel-rail coupling in the curve section.

[0007] The lateral excitation tooling includes an upper connecting flange, a vibration plate, a lateral spring, a fixed seat, a sliding guide block, and a vertical constraint spring; the upper connecting flange is arranged below the vibration plate, the lateral spring is horizontally arranged between the vibration plate and the fixed seat, and the sliding guide block is located above the vibration plate and is connected by a vertical constraint spring.

[0008] The upper part of the sliding guide block is connected to the upper platform by bolts. The lower part bears the coupled action of the vertical static load and the dynamic excitation system. The bottom is provided with rollers, which are in contact with the vibration plate. The vibration plate is provided with sliding rails, and a lateral sliding friction pair is formed between the rollers and the vibration plate, which can withstand a lateral force of 0 - 3000 N of the excitation rod and a high-frequency dynamic excitation load of 0 - 2000 Hz. The rollers can be other sliding devices with small friction force.

[0009] Further, the upper part of the excitation block contacts the roller, the lower part is connected to the upper connecting flange by bolts, the left part contacts the lateral spring, the right part is connected to the excitation rod, and the middle is constrained by the vertical spring. Further, the lateral spring is horizontally arranged between the fixed seat and the excitation plate and is horizontally placed so that the excitation plate can immediately return to the initial position after being displaced by the lateral excitation. Further, the upper part of the upper connecting flange is connected to the excitation plate, and the lower part is connected to the rail of the measured fastener system by a pin hole method.

[0010] Further, the upper part of the fixed seat in the lateral excitation tooling is connected to the upper platform by bolts, and the side is connected to the excitation plate by a lateral spring.

[0011] The static loading system includes a lower platform, an upper platform and guide columns. The measured fastener system is installed on the lower platform through a fastener installation tooling. The guide columns are placed on the lower platform, and the upper platform is connected to the upper part of the sliding guide rail block by bolts.

[0012] The upper platform is connected to a hydraulic drive assembly, and the upper platform is driven to move up and down along the guide columns by the hydraulic drive assembly to apply a static preloading force to the measured fastener system.

[0013] The dynamic excitation system includes an excitation rod, an exciter and an exciter fixed seat. The exciter fixed seat is installed on the lower platform, the exciter is installed on the exciter fixed seat, one end of the excitation rod is connected to the exciter, and the other end is laterally connected to the measured fastener system. The excitation rod can output high-frequency excitation power of 0-2000 Hz laterally through an amplifier and a controller.

[0014] The measured fastener system includes a rail, fasteners and a sleeper. The rail is connected to the upper connecting flange of the lateral excitation tooling by a pin hole method.

[0015] The measured fastener system is fixed on the lower platform of the static loading system through a fastener installation tooling.

[0016] Compared with the prior art, the present invention designs a lateral dynamic loading device for high-frequency stiffness testing of a railway fastener system. Under the coupling action of vertical pre-static load and lateral high-frequency excitation, a lateral sliding guide rail block friction pair is arranged under the preloading platform, the contact coefficient of the friction pair is very small, and the vibration-excited plate is fixed on the preloading platform. Therefore, the device can withstand a lateral excitation force of 0-3000 N and a dynamic frequency of 0-2000 Hz. The device has a reliable structural design and high feasibility, and can be used to cooperate with the high-frequency dynamic stiffness testing of railway fasteners or elastic elements. Description of the Drawings

[0017] Figure 1 It is the overall schematic diagram of the lateral high-frequency dynamic stiffness testing machine of the present invention;

[0018] Figure 2 Schematic diagram of the lateral high-frequency dynamic stiffness device of the present invention;

[0019] Figure 3 Axonometric view of the lateral high-frequency dynamic stiffness device of the present invention;

[0020] Figure 4 Schematic diagram of the structure of the sliding guide block of the present invention;

[0021] Figure 5 Schematic diagram of the structure of the excitation block of the present invention;

[0022] Figure 6 Schematic diagram of the structure of the connecting flange of the present invention;

[0023] Figure 7 Schematic diagram of the structure of the lateral spring of the present invention;

[0024] Figure 8 Schematic diagram of the structure of the vertical spring of the present invention;

[0025] Figure 9 Schematic diagram of the structure of the fixed seat of the present invention;

[0026] As shown in the figure, the reference numerals are: 1 - lateral excitation tooling, 101 - upper connecting flange, 102 - excitation plate, 103 - lateral spring, 104 - fixed seat, 105 - sliding guide block, 106 - vertical constraint spring, 107 - roller, 2 - dynamic excitation system, 201 - excitation rod, 202 - exciter, 203 - exciter fixed seat, 3 - measured fastener system, 301 - rail, 302 - fastener, 4 - fastener installation tooling, 5 - static loading system, 501 - lower platform, 502 - upper platform, 503 - guide post. Detailed implementation manners

[0027] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Embodiment 1

[0029] As Figure 1 shown, a lateral dynamic loading device for high-frequency stiffness testing of railway fasteners includes a lateral excitation tooling 1, a dynamic excitation system 2, a measured fastener system 3, a fastener installation tooling 4, and a static loading system 5. The dynamic excitation system 2 provides a high-frequency dynamic excitation force source with a certain amplitude for the fastener system of the testing device; the fastener installation tooling 4 is matched with the measured fastener and fixes the measured fastener system 3 to the lower platform 501 of the static loading system 5; the static preloading system 5 provides a certain static preloading force for the high-frequency dynamic stiffness of the railway fasteners. The lateral excitation tooling 1 is arranged below the upper platform 502 of the static loading system 5 and above the rail 301 of the measured fastener system 3.

[0030] Among them, the lateral excitation tooling 1, as Figures 2 - 3 shown, includes an upper connecting flange 101, a vibration excitation plate 102, a lateral spring 103, a fixed seat 104, a sliding guide block 105 and a vertical constraint spring 106; the upper part of the upper connecting flange 101 (as Figure 6 described) is connected to the vibration excitation plate 102, and the lower part is connected to the rail 301 of the measured fastener system 3 by a pin hole method. The lateral spring 103 (as Figure 7 shown) is horizontally arranged between the vibration excitation plate 102 and the fixed seat 104 and is horizontally placed so that the vibration excitation plate 102 can immediately return to the initial position after being displaced by lateral excitation. The sliding guide block 105 is located above the vibration excitation plate 102 and is connected by a vertical constraint spring 106. The structure of the vertical constraint spring 106 is as Figure 8 shown. The upper part of the sliding guide block 105 is connected to the upper platform 502 by bolts, the lower part bears the coupling action of the vertical static load and the dynamic excitation system, and a roller 107 (as Figure 4 shown) is provided at the bottom. The roller 107 contacts the vibration excitation plate 102, and a slide rail (as Figure 5 shown) is provided on the vibration excitation plate 102. A lateral sliding friction pair is formed between the roller 107 and the vibration excitation plate 102, which can bear the 0 - 3000N lateral force of the vibration excitation rod 201 and the 0 - 2000Hz high-frequency dynamic excitation load. The roller 107 can be other sliding devices with small friction.

[0031] The upper part of the excitation block 102 contacts the roller 107, the lower part is connected to the upper connecting flange 101 by bolts, the left part contacts the lateral spring 103, the right part is connected to the vibration excitation rod 201, and the middle is constrained by the vertical spring 106.

[0032] The fixed seat 104 in the lateral excitation tooling 1 (the structure is as Figure 9 shown) is connected to the upper platform 502 by bolts at the upper part and is connected to the vibration excitation plate 102 by the lateral spring 103 at the side.

[0033] The static loading system 5 includes a lower platform 501, an upper platform 502 and guide columns 503. The measured fastener system 3 is installed on the lower platform 501 through a fastener installation tooling 4. The guide columns 503 are placed on the lower platform 501. The upper platform 502 is connected to the upper part of the sliding guide block 105 by bolts. The upper platform 502 is connected to a hydraulic drive assembly, and the upper platform 502 is driven to move up and down along the guide columns 503 by the hydraulic drive assembly to apply a static preloading force to the measured fastener system 3.

[0034] The described dynamic excitation system 2 (TIRA-50350 from Germany) includes an excitation rod 201, an exciter 202, and an exciter fixing seat 203. The exciter fixing seat 203 is installed on the lower platform 501. The exciter 202 is installed on the exciter fixing seat 203. One end of the excitation rod 201 is connected to the exciter 202, and the other end is horizontally connected to the fastener system 3 to be measured. Through an amplifier and a controller, the excitation rod can output high-frequency excitation power of 0 - 2000 Hz horizontally.

[0035] The fastener system 3 to be measured includes a rail 301, fasteners 302, and a sleeper. The rail 301 is connected to the upper connection flange 101 of the horizontal excitation tooling 1 through a pin hole method.

[0036] The fastener system 3 to be measured is fixed on the lower platform 501 of the static loading system 5 through the fastener installation tooling 4.

[0037] During horizontal high-frequency excitation, first set the preloading force value of the static loading system 5 (force value 0 - 150 kN). Slowly control the upper loading platform 502 to slowly descend, driving the sliding guide block 105 to move downward together. Finally, the roller 107 of the sliding guide block 105 contacts the excitation plate 102 and is statically loaded to the set force value. At this time, lock the upper platform 502. Turn on the horizontal dynamic excitation system 2, set the excitation force and frequency of the exciter 202, so that the excitation rod 201 contacts the excitation plate 102. Under the action of the excitation force and frequency, due to the sliding friction pair with a very small friction coefficient between the roller 107 of the sliding guide block 105 and the excitation plate 102, under the action of the horizontal spring 103, the excitation plate 102 drives the rail 301 to reciprocate horizontally together with the set amplitude and frequency. The reciprocating frequency is 0 - 2000 Hz, so as to simulate the dynamic stiffness change characteristics of the railway fastener system under the action of wheel-rail coupling horizontal high-frequency excitation in the curve section through the test.

Claims

1. A lateral dynamic loading device for high-frequency stiffness testing of railway fasteners, comprising a dynamic excitation system (2), a fastener system under test (3), and a fastener installation tooling (4). Characterized in that the device further includes a lateral excitation tooling (1) and a static loading system (5). The lateral excitation tooling (1) is arranged between the static loading system (5) and the fastener system under test (3). Under the combined action of static preloading force and dynamic excitation, the lateral excitation tooling (1) drives the fastener system under test (3) to generate high-frequency, lateral reciprocating motion, with a lateral force range of 0 - 3000 N and a frequency range of 0 - 2000 Hz, simulating the dynamic stiffness change characteristics of the railway fastener system under the action of wheel-rail coupling lateral high-frequency excitation in the curve section; the lateral excitation tooling (1) includes an upper connecting flange (101), a vibration plate (102), a lateral spring (103), a fixed seat (104), a sliding guide block (105), and a vertical constraint spring (106); the upper connecting flange (101) is arranged below the vibration plate (102), the lateral spring (103) is horizontally arranged between the vibration plate (102) and the fixed seat (104), and the sliding guide block (105) is located above the vibration plate (102) and is connected by the vertical constraint spring (106); a roller (107) is provided at the bottom of the sliding guide block (105), and the roller (107) contacts the vibration plate (102) and forms a lateral sliding friction pair with the vibration plate (102); the static loading system (5) includes a lower platform (501), an upper platform (502), and guide columns (503). The fastener system under test (3) is installed on the lower platform (501) through the fastener installation tooling (4). The guide columns (503) are placed on the lower platform (501), and the upper platform (502) is connected to the upper part of the sliding guide block (105) by bolts.

2. The lateral dynamic loading device for high-frequency stiffness testing of railway fasteners according to claim 1, characterized in that the upper platform (502) is connected to a hydraulic drive component, and the hydraulic drive component drives the upper platform (502) to move up and down along the guide columns (503) and applies a static preloading force to the fastener system under test (3).

3. The lateral dynamic loading device for high-frequency stiffness testing of railway fasteners according to claim 1, characterized in that the dynamic excitation system (2) includes an excitation rod (201), an exciter (202), and an exciter fixed seat (203). The exciter fixed seat (203) is installed on the lower platform (501), the exciter (202) is installed on the exciter fixed seat (203), and one end of the excitation rod (201) is connected to the exciter (202), and the other end is laterally connected to the fastener system under test (3).

4. The lateral dynamic loading device for high-frequency stiffness testing of railway fasteners according to claim 1, characterized in that The fastener system (3) to be measured includes a rail (301), fasteners (302), and a sleeper. The rail (301) is connected to the upper connecting flange (101) of the lateral excitation tooling (1) through a pin hole method.

5. A lateral dynamic loading device for high-frequency stiffness testing of railway fasteners according to claim 4, characterized in that the fastener system (3) to be measured is fixed on the lower platform (501) of the static loading system (5) through a fastener installation tooling (4).

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