Device for applying dynamic load to rolling contact fatigue testing machine

Abstract

The utility model relates to the technical field of wheel-rail contact characteristic simulation test benches, in particular to a device for applying dynamic loading to a rolling contact fatigue testing machine, which is characterized in that a lever retainer is mounted on a workbench, and a pressure-bearing block is mounted at the bottom of one end of the lever retainer through a set screw; a hydraulic two-way cylinder installed on the workbench is arranged below the pressure-bearing block, a piston rod of the hydraulic two-way cylinder ascends and is loaded on the pressure-bearing block through a steel ball, and the lever retainer drives a driving shaft at one end to downwards transmit test force to a test accompanying shaft end with a transmission shaft as a fulcrum. Contact stress is generated between an upper test ring and a lower test ring which are respectively fastened with the driving shaft end and the accompanying shaft end. According to the utility model, the characteristic that the hydraulic bidirectional cylinder can reciprocate is utilized, and the accurate reciprocating motion of the hydraulic cylinder is realized through the displacement sensor, the servo valve, the oil distribution valve block, control software and the energy accumulator, so that the dynamic loading of upper and lower samples of the wheel-rail contact characteristic simulation test bed is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of wheel-rail contact characteristic simulation test benches, in particular to a device for applying dynamic loading to a rolling contact fatigue testing machine. Background Art

[0002] The hydraulic cylinder used in the existing wheel-rail contact characteristics simulation test bench is a one-way cylinder in the piston cylinder, which can only be used to apply pressure to the upward movement, and rely on gravity to fall back to achieve the application of constant positive pressure. As the country deepens its wheel-rail testing, there are more and more demands for test diversity, and dynamic loading is one of them. Dynamic loading means that the positive pressure applied to the specimen can be changed with a variable waveform, such as sine wave, triangle wave, square wave, etc., and the waveform frequency is variable. However, the positive pressure applied between specimens in the existing wheel-rail contact characteristics simulation test bench of the graphics card is a constant value and cannot change periodically with time and model.

[0003] To this end, the present application designs a device for applying dynamic loading to a rolling contact fatigue testing machine to solve the above-mentioned problem. Summary of the invention

[0004] In order to make up for the deficiencies in the prior art, the utility model provides a device for applying dynamic loading to a rolling contact fatigue testing machine.

[0005] A device for applying dynamic loading to a rolling contact fatigue testing machine, comprising a workbench, characterized in that:

[0006] A lever holder is installed on the workbench, and a pressure block is installed on the bottom of one end of the lever holder through a set screw. A hydraulic two-way cylinder installed on the workbench is provided below the pressure block. The piston rod of the hydraulic two-way cylinder rises and is loaded on the pressure block through a steel ball. The lever holder drives the active shaft at one end downward with the transmission shaft as a fulcrum to transmit the test force to the accompanying test shaft end, and contact stress is generated between the upper and lower test rings respectively fastened to the active shaft end and the accompanying test shaft end. The pressure between the test ring and the test block is measured by the load sensor of the hydraulic two-way cylinder and displayed on the control panel. The test force can be preset and fed back through a computer control system to achieve automatic control.

[0007] Furthermore, in order to better realize the utility model, a limit column is installed on one side of the hydraulic bidirectional cylinder of the workbench, and a hydraulic pump station is installed below the workbench.

[0008] Furthermore, in order to better implement the present invention, one end of the lever retaining frame is connected to a handle.

[0009] Furthermore, in order to better realize the utility model, the hydraulic bidirectional cylinder includes an oil dividing valve block, both ends of the oil dividing valve block are respectively connected to oil pipes, and both ends are also respectively connected to accumulators. The top of the piston rod of the hydraulic two-phase cylinder is connected to a load sensor through a sensor connecting plate, a steel ball is installed on the top of the load sensor, and a displacement sensor is installed at the bottom of the piston rod.

[0010] Furthermore, in order to better realize the utility model, a servo valve is installed on the hydraulic bidirectional cylinder, and feedback control is implemented through the current position of the piston and the positive pressure between the samples obtained by the load sensor and the displacement sensor to ensure that there is no error in the force value of dynamic loading.

[0011] The beneficial effects of the utility model are:

[0012] The utility model utilizes the reciprocating motion characteristic of the hydraulic bidirectional cylinder and realizes precise reciprocating motion of the hydraulic cylinder through a displacement sensor, a servo valve, an oil distribution valve block, control software and an accumulator, thereby realizing dynamic loading of upper and lower specimens of the wheel-rail contact characteristic simulation test bench. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of a rolling contact fatigue testing machine of the utility model;

[0014] Figure 2 It is a structural schematic diagram of a hydraulic bidirectional cylinder of the utility model;

[0015] Figure 3 It is a side sectional view of the hydraulic bidirectional cylinder of the utility model.

[0016] In the figure,

[0017] 1. Set screw, 2. Pressure block, 3. Steel ball, 4. Hydraulic bidirectional cylinder, 5. Limit column, 6. Lever retainer, 7. Hydraulic pump station, 8. Handle, 9. Workbench, 401. Oil distribution valve block, 402. Accumulator, 403. Load sensor, 404. Sensor connecting plate, 405. Piston rod, 406. Displacement sensor, 407. Servo valve. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the utility model provided in the accompanying drawings is not intended to limit the scope of the utility model claimed for protection, but merely represents selected embodiments of the utility model. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of the utility model.

[0020] Figure 1-Figure 3 This is a specific embodiment of the utility model, which is a device for applying dynamic loading to a rolling contact fatigue testing machine. This embodiment uses a hydraulic system as a power source, which is located at the bottom of the main machine and consists of an oil source and a hydraulic actuator. It is equipped with an adjusting needle valve, has long-term pressure maintenance and adjustment functions, and can achieve constant pressure loading. During the test, the cylinder piston pushes one end of the lever holder upward, and the driving shaft at the other end drives the main specimen to apply downward pressure to the accompanying specimen connected to the accompanying test shaft. The maximum load between the main and accompanying specimens is 30kN, and the load sensor measures the test load.

[0021] The hydraulic loading device of this embodiment is mainly composed of a hydraulic pump station 7 and a hydraulic cylinder bidirectional cylinder 4. The cylinder piston rises and is loaded on the pressure block 2 through the steel ball 3. The lever holder 6 drives the active shaft at one end downward with the transmission shaft as the fulcrum to transfer the test force to the companion shaft end, and contact stress is generated between the upper and lower test rings fastened to the active shaft end and the companion shaft end respectively. The pressure between the test ring and the test block is measured by the load sensor and displayed on the control panel. The test force can be preset and fed back through the computer control system to achieve automatic control. The pressure block 2 is fastened by the set screw 1. The handle 8 facilitates operation during the test. The limit column 5 is used to limit the downward position of the lever holder 6 to avoid collision.

[0022] This embodiment utilizes the reciprocating motion characteristic of the hydraulic bidirectional cylinder, and realizes precise reciprocating motion of the hydraulic cylinder through displacement sensors, servo valves, valve blocks, control software, and accumulators, thereby realizing dynamic loading of the upper and lower specimens of the wheel-rail contact characteristic simulation test bench. The scheme mainly includes a bidirectional hydraulic cylinder, a load sensor, a displacement sensor, an oil distribution valve block, and an accumulator. Two oil pipes are connected to the two ends of the oil distribution valve block to provide the necessary pressure for the reciprocating motion of the bidirectional cylinder. When the pressure at one end is high, the cylinder will move in the other direction, thereby realizing the reciprocating motion of the piston. The servo valve is the core of the regulation. The software obtains the current position of the piston and the size of the positive pressure between the specimens through load sensors and displacement sensors, and compares these data with the standard value to be achieved, thereby realizing feedback control. For example, when a sinusoidal wave signal is input, the data fed back by the servo valve through the sensor ensures that there will be no error in the force value of the dynamic loading.

[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the utility model by ordinary technicians in this field should be included in the scope of the claims of the utility model as long as they do not depart from the spirit and scope of the technical solution of the utility model.

Claims

1. A device for applying dynamic loading to a rolling contact fatigue testing machine, comprising a workbench (9), characterized in that: The workbench (9) is provided with a lever holder (6), and a pressure block (2) is installed at the bottom of one end of the lever holder (6) via a set screw (1). A hydraulic two-way cylinder (4) installed on the workbench (9) is provided below the pressure block (2). The piston rod (405) of the hydraulic two-way cylinder (4) rises and is loaded on the pressure block (2) via a steel ball (3). The lever holder (6) drives the driving shaft at one end downward with the transmission shaft as a fulcrum to transmit the test force to the accompanying test shaft end. Contact stress is generated between the upper and lower test rings respectively fastened to the driving shaft end and the accompanying test shaft end. The pressure between the test ring and the test block is measured by a load sensor (403) of the hydraulic two-way cylinder (4) and displayed on a control panel. The test force can be preset and fed back via a computer control system to achieve automatic control.

2. The device for applying dynamic loading to a rolling contact fatigue testing machine according to claim 1, characterized in that: The workbench (9) is provided with a limit column (5) on one side of the hydraulic bidirectional cylinder (4), and a hydraulic pump station (7) is provided below the workbench (9).

3. The device for applying dynamic loading to a rolling contact fatigue testing machine according to claim 1, characterized in that: One end of the lever retaining frame (6) is connected to a handle (8).

4. The device for applying dynamic loading to a rolling contact fatigue testing machine according to claim 1, characterized in that: The hydraulic bidirectional cylinder (4) comprises an oil distribution valve block (401), both ends of the oil distribution valve block (401) are respectively connected to oil pipes, and both ends are also respectively connected to accumulators (402), the top of the piston rod (405) of the hydraulic bidirectional cylinder (4) is connected to a load sensor (403) via a sensor connecting plate (404), a steel ball (3) is installed on the top of the load sensor (403), and a displacement sensor (406) is installed at the bottom of the piston rod (405).

5. The device for applying dynamic loading to a rolling contact fatigue testing machine according to claim 1, characterized in that: The hydraulic bidirectional cylinder (4) is provided with a servo valve (407), and feedback control is implemented by obtaining the current position of the piston and the positive pressure between the test specimens through the load sensor (403) and the displacement sensor (406), thereby ensuring that there is no error in the force value of the dynamic loading.

Images