CN108956353A - Railway ballast particle high frequency micro-moving frictional wear experiment test device - Google Patents

Abstract

The present invention relates to fine motion frictional dissipation experimental technique fields.The invention discloses a kind of railway ballast particle high frequency micro-moving frictional wear experiment test devices, including fine motion power device, plane sample holding device, temperature control device, constant flow rate water-bath circulator, spherical sample holding device and data collection system；The fine motion power device is connect with plane sample holding device, for providing the effect of simulation train load, the plane sample of the plane sample holding device clamping, the spherical sample contacts with the spherical sample holding device clamping；The temperature control device is mounted on inside plane sample holding device, for setting test temperature；The constant flow rate water-bath circulator is installed on the plane sample holding device, for providing the water-bath effect of the simulation constant flow rate that railway ballast sample is subject to；The data collection system, for acquiring railway ballast sample stress and displacement.The present invention can real simulation train to the dynamic loading of railway ballast particle.

Description

High-frequency fretting friction and wear test device for railway ballast particles

technical field

The invention relates to the technical field of fretting friction loss testing, in particular to a test device for high-frequency fretting friction and wear testing of railway ballast particles under the coupled action of water flow-temperature-load.

Background technique

Fretting is the relative movement of two contact surfaces with extremely small amplitude, which can cause friction and wear of the contact surfaces and the generation and expansion of fatigue cracks.

In 1924, Gillet first discovered the phenomenon that the fatigue life of machine fasteners was significantly reduced due to fretting. However, due to the limitations of test equipment and testing technology at that time, the research progress of fretting friction and wear was relatively slow. After the 1970s, with the development of microscopic analysis and testing technology, fretting tribology has also developed rapidly, and new academic ideas have been continuously introduced into the research of fretting tribology, which has enriched and developed the theory of fretting tribology. , such as the introduction of the theory of large displacement sliding wear delamination and the theory of fretting three-body friction and wear.

Ballast particles are usually processed from stone, and are an important material for laying ballast track bed. In engineering, according to the material performance and parameter index of crushed stone ballast, it is divided into special grade ballast, first grade ballast and second grade ballast. In order to increase the stability of ballast in high-speed railways, reduce wear and pulverization caused by vibration, and prevent ballast splashing during high-speed driving, special-grade ballast is usually used. Super ballast reflects ballast material parameters (material indicators such as wear resistance, impact resistance, crush resistance, water seepage, weathering resistance, and atmospheric corrosion resistance) and quality parameters reflecting ballast performance (ballast particle size, gradation, Particle shape, surface condition, cleanliness and other processing indicators) are much higher than other grades of ballast. That is to say, high-speed railway ballast has very strict requirements on the wear between its particles.

In order to meet the dynamic requirements of high-speed trains, the stability requirements of the track bed under the dynamic load cycle of the train are extremely strict. Under the action of train dynamic load, the interaction between ballast particles belongs to the category of high-frequency fretting friction and wear. With the development of fretting movement between ballast particles, the micro-structure level and distribution characteristics of ballast particles change, and fretting slip zones appear between adjacent particles. In the fretting slip zone, when the contact shear stress between the micro-contact peaks on the surface of ballast particles exceeds the material shear strength, fracture occurs at the contact peaks, and abrasive particles are formed between the contact surfaces of adjacent ballast particles; and the ballast surface roughness The existence of waviness and waviness lead to discontinuous contact between adjacent particles. Under repeated high-speed train loads, the surface of ballast particles is subjected to periodic fretting loads, and fatigue fractures occur at the micro-contact peaks on the surface. Abrasive particles are formed between the contact surfaces of adjacent ballast particles.

Abrasive particles continue to develop, forming and removing abrasive particles between the contact surfaces of adjacent ballast particles to reach a dynamic balance, and the fretting friction and wear between ballast particles enters a stable stage. Under the action of water infiltrated into the ballast bed, the microscopic contact between the contact surfaces of the ballast particles is greatly weakened, which provides the necessary conditions for the generation of accumulative deformation of the ballast bed. At the same time, the temperature will affect the lubricating viscosity of the bound water film between the ballast particles to a certain extent. Therefore, in order to improve the deformation stability of the ballasted track bed during service, it is extremely necessary to carry out experimental research on high-frequency fretting friction and wear between ballast particles under the coupled action of water flow-temperature-load.

At present, in the field of mechanical engineering, there are research and test equipment on fretting friction and wear. The fretting friction and wear in the mechanical field is mainly aimed at metal materials and organic matter, and the high frequency of fretting friction and wear between railway ballast particles. And the characteristics of water flow-temperature-load coupling, there is no relevant test equipment at present. For the stone inorganic matter such as ballast particles used in railway engineering, no relevant research has been seen so far. Compared with metals and organic substances, the biggest characteristic of stone is brittleness. The brittleness of the material causes ballast particles to easily drop abrasive particles on the surface during the process of fretting friction and wear, and the abrasive particles are prone to form a "fluid-wrapped abrasive particle three-body lubrication effect" under the action of water (roller in the bearing Lubrication principle), leading to relative displacement between ballast particles, excessive inter-particle displacement will further cause excessive macroscopic accumulation deformation of ballast ballast bed, which will cause harm to high-speed driving comfort and driving safety.

Therefore, the fretting friction and wear between ballast particles considering the coupling effect of water flow-temperature-load plays a very critical role in maintaining the stability of railway ballast. At present, there is no experimental device for experimental research on fretting friction and wear between railway ballast particles in the prior art.

Contents of the invention

The main purpose of the present invention is to provide a test device for high-frequency fretting friction and wear between railway ballast particles, which is used to study the high-frequency fretting friction and wear characteristics between railway ballast particles.

In order to achieve the above object, according to an aspect of the specific embodiment of the present invention, a high-frequency fretting friction and wear test device for railway ballast particles is provided, which is characterized in that it includes a fretting power device, a plane sample clamping device, Temperature control device, constant flow rate water bath circulation device, spherical sample clamping device and data acquisition system; the micro-motion power device is connected with the plane sample clamping device to provide the effect of simulating train load, and the plane sample The plane sample clamped by the clamping device is in contact with the spherical sample clamped by the spherical sample clamping device; the temperature control device is installed inside the plane sample clamping device for setting the test temperature; The constant flow rate water bath circulation device is installed on the plane sample clamping device, which is used to provide the water bath effect of simulating the constant flow rate of the ballast sample; the data acquisition system is used to collect the ballast sample force and displacement.

Further, the micro-motion power device includes a servo motor and a transmission, the servo motor is connected to the transmission, and the transmission is connected to the plane sample holding device.

Further, the servo motor and transmission are controlled by a computer to provide micron-level high-frequency vertical and horizontal circular translation and reciprocating rotation for the planar sample clamping device.

Further, the plane sample clamping device has an adjustment mechanism for stably clamping samples of different sizes.

Further, the constant flow rate water bath circulation device includes a water flow circulation system and a constant flow rate water bath.

Further, the temperature control device adopts digital control technology, which is used to control the water and samples in the water bath with constant flow rate to keep at the set temperature.

Further, the spherical sample holding device is used to firmly hold ballast spherical sample particles of different particle sizes.

Further, the data acquisition system is used to acquire the force and displacement of the ballast sample during high-frequency vertical and horizontal cyclic translation.

The beneficial effect of the present invention is that, fully considering the effect of the real environment of water flow-temperature-load coupling on the fretting friction and wear between ballast particles, it is possible to truly simulate the test dynamics of the dynamic load action form of the train on ballast particles changing with time. Load, the data collected in the test is conducive to the research on the stability maintenance technology of railway ballast, and is conducive to the optimization and improvement of railway ballast.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The drawings constituting a part of this application are used to provide a further understanding of the present invention, and the specific implementation modes, schematic embodiments and descriptions thereof of the present invention are used to explain the present invention, and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is the structural representation of embodiment;

Fig. 2 is a horizontal sectional view of the plane sample holding device;

Fig. 3 is a vertical sectional view of a plane sample holding device;

Fig. 4 is a horizontal section view of the temperature control device inside the base of the plane sample holding device;

Fig. 5 is a vertical sectional view of the high-frequency micro-motion power device;

Fig. 6 is a vertical sectional view of the water circulation system;

Fig. 7 is a vertical sectional view of a spherical sample holding device.

in:

1 is the plane sample contact pad;

2. Hold the fine-tuning bolts for the flat sample;

3 is the water inlet;

4 is the water outlet;

5 is the incoming and outgoing wire;

6 is a high-precision numerically controlled constant temperature tube;

7 is the base;

8 is a high-frequency transmission;

9 is a high-precision servo motor;

10 is a high-precision flow rate water circulation pump;

11 is a constant temperature water tank;

12 is a temperature control tube;

13 is a bearing;

14 is a water injection port;

15 is a plane sample;

16 is a spherical sample;

17 is a 6-dimensional force/torque sensor;

18 is a spherical sample clamping device connecting rod;

19 is the spherical sample clamping fine adjustment bolt;

20 is a spherical sample contact pad;

21 is a water circulation system and a constant flow rate water bath.

Detailed ways

It should be noted that, in the case of no conflict, the specific implementation methods, examples and features in the present application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and in conjunction with the following contents.

In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the specific embodiments of the present invention and the examples will be clearly and completely described below in conjunction with the accompanying drawings in the specific embodiments of the present invention and the examples. , the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the specific implementation modes and examples in the present invention, all other implementation modes and examples obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

The high-frequency fretting friction and wear test device for railway ballast particles of the present invention, through the interaction between two ballast samples, a plane sample and a spherical sample, simulates the interaction between ballast particles in a ballast track bed. The high-frequency fretting friction is used to collect ballast friction and wear data.

As shown in Figure 1, the high-frequency fretting friction and wear test device for railway ballast particles of the present invention includes a fretting power device, a plane sample clamping device, a temperature control device, a constant flow rate water bath circulation device, and a spherical sample holder holding device and data acquisition system.

The micro-motion power device is connected with the plane sample clamping device, and its structure includes a servo motor and a transmission. The servo motor is connected with the transmission, and the transmission is connected with the plane sample clamping device.

Both the servo motor and the transmission are controlled by the computer, which can provide micron-level high-frequency vertical and horizontal circular translation and reciprocating rotation for the plane sample clamping device and the spherical sample clamping device, simulating the effect of the train load.

During the test, the plane ballast sample clamped by the plane sample clamping device transmits the simulated train load to the spherical sample by contacting the spherical ballast sample clamped by the spherical sample clamping device. Under the control of the computer, the high-frequency micro-movement produced by the servo motor and the transmission is transmitted to the two ballast samples, and the interaction between them will produce the friction and wear of the ballast samples.

The temperature control device is installed inside the flat sample clamping device. Using digital control technology, it can precisely control the water and samples in the water bath with constant flow rate, and keep the test at the set temperature.

The constant flow rate water bath circulation device is installed on the plane sample holder to provide simulation of ballast being subjected to constant flow rate water bath.

The data acquisition system is installed on the spherical sample holder to collect the force and displacement of two ballast samples.

Example

With reference to Fig. 1, Fig. 2, Fig. 3 and Fig. 5, the high-frequency fretting friction and wear test device of railway ballast particles of the present invention, in the test process, the fretting friction and wear between spherical samples and flat sample ballast particles are mutually The acting power comes from a high-precision servo motor 9 and a high-frequency transmission 8 installed at the bottom of the plane sample platform base 7 . The servo motor 9 combined with the high-frequency transmission 8 installed at the front end can provide micron-level high-frequency vertical and horizontal circular translation and reciprocating rotation for the planar sample holding device and the spherical sample holding device.

The planar sample holding device is composed of a base 7 and a water bath 21 . The plane sample 15 is fixed on the plane sample holding device by the plane sample holding device. The flat sample clamping device has an adjustment mechanism for stably clamping samples of different sizes.

The adjustment mechanism of the plane sample clamping device is composed of the plane sample fine adjustment bolt 2 and the plane sample contact cushion block 1 . The ballast sample moves slightly together with the flat sample clamping device and the spherical sample clamping device to realize micron-level high-frequency vertical and horizontal circular translation and reciprocating rotation between the ballast sample particles.

Referring to Fig. 3, Fig. 4 and Fig. 6, during the test, the constant flow rate water bath circulation device composed of the water flow circulation system and the constant flow rate water bath 21 can realize the constant flow rate water flow in the water bath.

Water flows into the water circulation system and the constant flow rate water bath 21 from the water inlet 3 , and then flows out from the water outlet 4 . During this process, the temperature of the water bath can be controlled within the error range of ±2°C of the set temperature. The constant flow rate water bath circulation device of this example is made of high precision flow rate water flow circulation pump 10 and additional digital temperature control water tank 11. In order to further precisely control the temperature of the water bath, inside the base 7 of the plane sample holding device, there is a high-precision numerically controlled constant temperature tube 6, and its inlet and outlet wires 5 are connected to the computer, which can precisely control the temperature of the water bath in the water bath with constant flow rate. The temperature is within the error range of ±0.5°C. The constant flow rate water bath circulation device combined with the temperature control device can simulate the high-frequency fretting friction and wear test research on ballast particles under the coupled action of water flow-temperature-load.

Referring to Figure 7, a spherical specimen 16 is secured to the spherical specimen holder. The spherical sample clamping device is composed of a spherical sample clamping fine-tuning bolt 19 and a spherical sample contact pad 20, which can stabilize spherical samples of different particle sizes. During the test, the time-course data of the contact force and torque between the spherical sample and the plane sample over time are collected by the 6-dimensional force/torque sensor 17 installed on the connecting rod 18 of the spherical sample clamping device. The collected contact force/torque time-history data can be exported to the computer for later analysis and analysis of high-frequency fretting friction and wear tests between railway ballast particles under the coupled action of water flow-temperature-load.

Claims (8)

1. railway ballast particle high frequency micro-moving frictional wear experiment test device, which is characterized in that including fine motion power device, put down Face sample holding device, temperature control device, constant flow rate water-bath circulator, spherical sample holding device and data collection system； The fine motion power device is connect with plane sample holding device, for providing the effect of simulation train load, the plane examination The plane sample of sample gripping apparatus grips, the spherical sample contacts with the spherical sample holding device clamping；The temperature control dress It sets and is mounted on inside plane sample holding device, for setting test temperature；The constant flow rate water-bath circulator is installed on On the plane sample holding device, for providing the water-bath effect of the simulation constant flow rate that railway ballast sample is subject to；The data Acquisition system, for acquiring railway ballast sample stress and displacement.

2. railway ballast particle high frequency micro-moving frictional wear experiment test device according to claim 1, which is characterized in that The fine motion power device includes servomotor and speed changer, and the servomotor is connect with speed changer, the speed changer It is connect with plane sample holding device.

3. railway ballast particle high frequency micro-moving frictional wear experiment test device according to claim 2, which is characterized in that The servomotor and speed changer are controlled by computer, are provided micron-sized high frequency for plane sample holding device and are vertically and horizontally followed Ring translation and reciprocating rotation.

4. railway ballast particle high frequency micro-moving frictional wear experiment test device according to claim 1, which is characterized in that The plane sample holding device has regulating mechanism, for the firm clamping to different size sample.

5. railway ballast particle high frequency micro-moving frictional wear experiment test device according to claim 1, which is characterized in that The constant flow rate water-bath circulator includes water circulation system and constant flow rate water bath.

6. railway ballast particle high frequency micro-moving frictional wear experiment test device according to claim 1, which is characterized in that The temperature control device uses digital control technology, is maintained at set temperature for controlling water in constant flow rate water bath and sample Under.

7. railway ballast particle high frequency micro-moving frictional wear experiment test device according to claim 1, which is characterized in that Railway ballast spherical shape sample particle of the spherical shape sample holding device for firm clamping different-grain diameter.

8. railway ballast particle high frequency micro-moving frictional wear experiment test device according to claim 1, which is characterized in that The data collection system is for obtaining railway ballast sample stress and displacement when high frequency vertically and horizontally recycles translation.