A multifunctional wheel-rail adhesion creep testing machine and simulation test method

Abstract

This invention discloses a multifunctional wheel-rail adhesion and creep testing machine and a simulation testing method. The testing machine mainly consists of a drive motor, three gear sets, a slip adjustment device, a clutch, a vertical force loading device, a moment of inertia disk, a simulated wheel and rail, a magnetic powder brake, a pressure sensor, a torque sensor, and an encoder. The simulation testing method involves configuring initial test parameters and then starting the device. Once the system stabilizes, the electric cylinder is activated to simulate wheel-rail loads. Furthermore, by adjusting the clutch state, the position and loading torque of the magnetic powder brake, the drive motor control mode, and the torque required for simulating a slope, simulation tests can be performed under four working conditions: wheel-rail adhesion, parking braking, uniform speed movement on a long downhill slope, and uniform speed traction on a long uphill slope. This invention is of great significance for studying the wheel-rail interface adhesion mechanism and adhesion control under various working conditions.

Description

Technical Field

[0001] This invention belongs to the field of wheel-rail friction simulation test technology, and particularly relates to a multifunctional wheel-rail adhesion creep test machine and simulation test method. Background Technology

[0002] Wheel-rail rolling friction is crucial for converting locomotive wheel torque into traction force. Failure of wheel-rail adhesion leads to wheel spin during traction, causing rail abrasion; failure during braking results in wheel slippage and further abrasion. Therefore, studying the adhesion mechanism of the wheel-rail interface under different operating conditions is the technical foundation for effective control of wheel-rail adhesion.

[0003] Currently, existing wheel-rail rolling test benches and braking test benches have limited functions. Among them, testing machines simulating wheel-rail adhesion mainly include dual-motor driven wheel-rail friction and wear testing machines and single-drive friction and wear testing machines. For example, the JD-1 wheel-rail simulation testing machine developed by Southwest Jiaotong University, the MJP wheel-rail rolling contact friction and wear testing machine, and the British SUROS double-disc friction testing machine are dual-motor driven wheel-rail friction and wear testing machines. They can control slip by changing the speed of two servo motors, and the testing machines use hydraulic loading, resulting in high load control accuracy, but the overall testing device consumes a lot of energy. The WR-1 wheel-rail rolling wear testing machine, the JPM-1 contact fatigue wear testing machine, and the MMS-2A microcomputer-controlled friction and wear testing machine are single-motor driven friction and wear testing machines. The entire testing device's mechanical structure forms a closed loop, saving energy. However, these three types of single-drive testing machines have a constant slip speed, which cannot be continuously varied. Slip can only be changed by altering the number of gear teeth, and these machines often use spring loading, resulting in low load control accuracy. Summary of the Invention

[0004] To address the above shortcomings, this invention provides a multifunctional wheel-rail adhesion creep testing machine and simulation testing method.

[0005] The present invention discloses a multifunctional wheel-rail adhesion creep testing machine, the specific structure of which is as follows: a drive motor is connected to gear set A via a coupling, wherein gear set A includes gears Z1, Z2, Z3, and Z4 meshing sequentially, the transmission ratio of gears Z1 to Z2 is 3, the transmission ratio of gears Z2 to Z4 is 1, gear Z3 is a reversing gear, the shaft of gear Z4 is connected to the input shaft of the slip adjustment device via a coupling, the output shaft of the slip adjustment device is connected to clutch 2, gear set B is connected to the other end of clutch 2, gear set B includes gears Z5 and Z6 meshing with each other, the transmission ratio of gears Z5 to Z6 is 1 / 3, one end of gear Z6 is connected to the moment of inertia disk via a universal joint, and the other end is connected to the simulated wheel sample, the left side of the simulated wheel sample is connected to... Encoder 1 is connected; the vertical force loading device is connected to gears Z5 and Z6 via bearings; gear Z2 is connected to clutch 1; clutch 1 is connected to torque sensor via coupling; torque sensor is connected to simulated rail sample; the right side of simulated rail sample is connected to encoder 2; gear set C is connected to the left side of clutch 1; gear set C includes meshing gears Z7 and Z8; gear Z8 is connected to brake via coupling; slip adjustment device includes planetary gear differential and loading motor; vertical force loading device includes: a movable rod connected to gears Z5 and Z6 via bearings; loading electric cylinder is mounted on the frame; a force sensor is installed on the top of the loading electric cylinder telescopic rod to detect the magnitude of the vertical force loaded on the simulated wheel sample.

[0006] The vertical force loading device mainly includes a loading electric cylinder and a movable rod. The movable rod is connected to the upper sample shaft and gear Z5 shaft through bearings. The loading electric cylinder applies load to the free end of the movable rod, and the magnitude of the loading vertical force is detected by a force sensor fixed to the top of the loading electric cylinder.

[0007] The multifunctional wheel-rail adhesion and creep testing machine of the present invention can perform adhesion tests, parking braking, uniform braking on long downhill slopes, and uniform traction on long uphill slopes.

[0008] During the simulated adhesion test, the moment of inertia disk is not engaged, clutches 1 and 2 are closed, and the mechanical closed system consists of the drive motor, gears Z2, Z3, and Z4, the slip adjustment device, the vertical force loading device, gear set B, encoder 1, encoder 2, the simulated wheel, the simulated rail, and the torque sensor. The slip adjustment device includes a planetary gear differential and a loading motor. The transmission ratio of the planetary gear differential is 3, the transmission ratio of gear set B is 1 / 3, and the total transmission ratio of the entire closed system is 1. At the start of the test, the speed-controlled drive motor is used to rotate the simulated wheel and simulated rail samples at a constant speed. A constant force is applied between the wheel and rail samples by a controlled loading electric cylinder. After the system stabilizes, the torque of the loading motor is controlled to induce creep between the wheel and rail, thus conducting a wheel-rail adhesion and creep test. A torque sensor is used to measure the tangential force between the simulated wheel and rail samples, and a force sensor is used to measure the magnitude of the loading normal force. The wheel-rail adhesion coefficient is obtained by dividing the wheel-rail tangential force by the wheel-rail normal force. Encoders 1 and 2 are used to measure the rotational speed of the wheel and rail samples, and the speed difference between the wheel and rail samples is calculated. The creep rate is obtained by dividing the speed difference by the rotational speed of the simulated wheel sample. Finally, the wheel-rail adhesion-creep characteristic curve is displayed by the data acquisition and processing system.

[0009] During the simulated parking brake test, the brake is connected to gear Z8 via a coupling, and the moment of inertia disk is connected to gear Z6 via a universal joint. The drive motor operates at a constant speed in speed control mode, and the loading electric cylinder applies a constant force between the wheel and rail sample. After the system stabilizes, clutches 1 and 2 disengage, the drive motor stops, and the brake is energized to input a certain braking torque to simulate the parking brake process. The data acquisition and processing system displays the wheel-rail adhesion-creep characteristic curve.

[0010] When simulating a constant speed braking test on a long downhill slope, the brake is connected to the gear Z8 shaft via a coupling, and the moment of inertia disk is connected to the gear Z6 via a universal joint. The drive motor operates at a constant speed in speed control mode, and the loading cylinder applies a constant force between the wheel and rail sample. After the system stabilizes, clutch 1 disengages and clutch 2 engages. The drive motor then simulates the acceleration of the train along the slope in torque control mode. The brake inputs a certain braking torque to make the train run at a constant speed, simulating the downhill constant speed braking process. The data acquisition and processing system displays the wheel-rail adhesion-creep characteristic curve.

[0011] When simulating a constant-speed traction test on a long uphill slope, the brake and gear Z5 are connected via a coupling, and the moment of inertia disk and gear Z6 are connected via a universal joint. The drive motor operates the entire system at a certain speed in speed control mode, and the loading cylinder applies a constant force between the wheel and rail sample. After the system stabilizes, clutch 1 is engaged and clutch 2 is disengaged. The drive motor simulates the traction force required for the train to go uphill in torque control mode, and the brake inputs a certain braking torque to simulate the resistance encountered by the train during the uphill process, so that the train runs at a constant speed. The data acquisition and processing system displays the wheel-rail adhesion-creep characteristic curve.

[0012] The beneficial technical effects of this invention are as follows:

[0013] 1. This invention enables the simulation of wheel-rail adhesion tests, parking braking, uniform braking on long downhill slopes, and uniform traction on long uphill slopes on a multifunctional wheel-rail adhesion creep testing machine. It is of great significance for studying the wheel-rail interface adhesion mechanism and adhesion control under different working conditions.

[0014] 2. This invention can calculate and simulate the acceleration along the slope direction when going downhill and the resistance encountered when going uphill in real time, and then adjust the motor torque. It can simulate the wheel-rail adhesion state of the train when running on the slope from the perspective of the forces exerted on the train on the slope. Compared with the previous method of simulating the slope by designing fixtures, it saves design costs.

[0015] 3. This invention uses a servo-loaded electric cylinder to apply vertical force to the wheel-rail sample, which has the advantages of high loading accuracy and fast response speed compared with the previous testing machine that used spring loading. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the principle of the device of the present invention.

[0017] Figure 2 This is a schematic diagram of the overall structure of the device of the present invention.

[0018] Figure 3 This is a schematic diagram of the vertical force loading device structure of the present invention.

[0019] Figure 4 This is a schematic diagram of the vertical force loading device of the present invention.

[0020] Figure 5 This is a flowchart of the simulation test control method and data acquisition process of the present invention.

[0021] In the diagram: 1-Drive motor, 2-Coupling, 3-Gear set A, 4-Gear Z1, 5-Gear Z2, 6-Gear Z4, 7-Gear Z3, 8-Slip adjustment device, 9-Loading motor, 10-Sun gear, 11-Planetary carrier, 12-Clutch 2, 13-Vertical force loading device, 14-Gear set B, 15-Gear Z5, 16-Momentum of inertia disk, 17-Frame, 18-Gear Z6, 19-Encoder 1, 20-Simulated wheel sample, 21-Simulated rail sample, 22-Encoder 2, 23-Torque sensor, 24-Brake, 25-Gear set C, 26-Gear Z8, 27-Gear Z7, 28-Clutch 1, 1301-Moving rod, 1302-Force sensor, 1303-Gear Z5 shaft, 1304-Simulated wheel sample shaft, 1305-Frame, 1306-Support platform, 1307-Loading electric cylinder. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0023] like Figure 1 , Figure 2As shown, the multi-functional wheel-rail adhesion creep tester drive motor 1 is connected to gear set A (3) through coupling 2. Gear set A (3) mainly includes gears Z1 (4), Z2 (5), Z3 (7), and Z4 (6) meshing in sequence. The transmission ratio between gears Z1 (4) and Z2 (5) is 3, and the transmission ratio between gears Z2 (5) and Z4 (6) is 1. Gear Z3 (7) is a reversing wheel. The shaft of gear Z4 (6) is connected to the input shaft of slip adjustment device 8 through coupling. Slip adjustment device 8 includes a planetary gear differential and a loading motor 9. The output shaft of slip adjustment device 8 is connected to clutch 2. Gear set B (14) is connected to the other end of clutch 2 (12). Gear set B (14) mainly includes gears Z5 (15) and Z6 (18) meshing with each other. The transmission ratio between gears Z5 (15) and Z6 (18) is 1 / 3, and the transmission ratio between gears Z6 (15) and Z6 (18) is 1 / 3. 8) One end is connected to the moment of inertia disk 16 via a universal joint, and the other end is connected to the upper sample 20. The left side of the simulated wheel sample 20 is connected to the encoder 1 (19). The vertical force loading device 13 is connected to the shafts of gears Z5 (15) and Z6 (18) via bearings. The shaft of gear Z2 (5) is connected to the clutch 1 (28). The clutch 1 (28) is connected to the torque sensor 23 via a coupling. The torque sensor 23 is connected to the simulated rail sample 21. The right side of the simulated rail sample 21 is connected to the encoder 2 (12). The gear set C is connected to the left side of the clutch 1 (19). The gear set C (25) includes gears Z7 (27) and Z8 (26) that mesh with each other. Gear Z8 (26) mainly includes gears Z7 (27) and Z8 (26). The transmission ratio of gears Z7 (27) and Z8 (26) is 1. The gear set C (25) is connected to the brake 24 via a coupling.

[0024] The structure and principle of the vertical force loading device are as follows: Figure 3 , Figure 4 As shown, the movable rod 1301 is connected to the gear Z5 and Z6 shafts via bearings. The loading electric cylinder 1307 is mounted on the frame 17. A force sensor 1302 is installed on the top of the loading electric cylinder telescopic rod to detect the magnitude of the vertical force applied to the simulated wheel sample.

[0025] like Figure 5As shown in the simulation test method and data acquisition flowchart, when simulating the adhesion test, the drive motor 1, gear set A (3), slip adjustment device 8, vertical force loading device 13, gear set B (14), encoder 1 (19), encoder 2 (12), simulation wheel 20, simulation rail sample 21, torque sensor 23, clutch 1 (28), and clutch 2 (12) form a mechanical closed system. The test method is as follows: First, configure the initial parameters, then start the drive motor. After the system stabilizes, start the loading electric cylinder to load the system. Adjust the torque of the loading motor. The wheel and rail can be made to creep through the slip adjustment device to conduct the wheel-rail adhesion and creep test. Finally, the torque sensor 23 is used to measure the tangential force between the simulated wheel sample 20 and the simulated rail sample 21, and the force sensor 1302 is used to measure the magnitude of the loading normal force. The wheel-rail tangential force divided by the wheel-rail normal force is the wheel-rail adhesion coefficient. The encoders 1 and 2 are used to measure the rotational speed of the wheel and rail samples, and the rotational speed difference between the wheel and rail samples is calculated. The creep rate is obtained by dividing the rotational speed difference by the rotational speed of the simulated wheel sample. Finally, the wheel-rail adhesion-creep characteristic curve is displayed by the data acquisition and processing system.

[0026] like Figure 5 As shown in the simulation test method and data acquisition flowchart, when simulating the parking brake test, the brake 24 is connected to the gear Z8 (26) through a coupling, and the moment of inertia disk 16 is connected to the gear Z6 (18) through a universal joint. The test method is as follows: the drive motor 1 operates the entire system at a constant speed in the speed control mode, and the loading cylinder is controlled to apply a certain force to the wheel-rail sample. After the system stabilizes, the clutches 1 and 2 are disengaged, the drive motor stops running, and the brake 24 is energized to input a certain braking torque to simulate the wheel-rail adhesion state during the train parking brake process. The wheel-rail adhesion-characteristic curve is displayed by the data acquisition and processing system.

[0027] like Figure 5 As shown in the simulation test method and data acquisition flowchart, when simulating the uniform speed braking test on a long downhill slope, the brake 24 and the gear Z8 (26) shaft are connected by a coupling, and the moment of inertia disk 16 and the gear Z6 (18) are connected by a universal joint. The test method is as follows: the drive motor runs the entire system at a constant speed in the speed control mode, and the loading cylinder is controlled to apply a certain force to the wheel and rail sample. After the system stabilizes, the clutch 1 is disengaged and the clutch 2 is closed. The drive motor 1 simulates the acceleration of the train along the slope in the torque control mode. The brake 24 inputs a certain braking torque to make the train run at a uniform speed, simulating the uniform speed braking process on the downhill slope. The wheel and rail adhesion-creep characteristic curve is displayed by the data acquisition and processing system.

[0028] like Figure 5As shown in the simulation test method and data acquisition flowchart, when simulating the uniform speed traction test of a long uphill slope, the brake 24 is connected to the gear Z6 (18) through a coupling, and the moment of inertia disk 16 is connected to the gear Z6 (18) through a universal joint. The test method is as follows: the drive motor runs the entire system at a certain speed in the speed control mode, and the loading cylinder is controlled to apply a certain force to the wheel-rail sample. After the system stabilizes, the clutch 2 is closed and the clutch 1 is disengaged. The drive motor 1 simulates the traction force required for the train to go uphill in the torque control mode. The brake 24 inputs a certain braking torque to simulate the resistance encountered by the train during the uphill process, so that the train runs at a uniform speed and simulates the uniform speed uphill traction process of the train.

Claims

1. A multifunctional wheel-rail adhesion creep testing machine, characterized in that, The drive motor (1) is connected to the gear set A (3) via a coupling (2). The gear set A (3) includes gears Z1 (4), Z2 (5), Z3 (7), and Z4 (6) that mesh sequentially. The transmission ratio between gears Z1 (4) and Z2 (5) is 3, and the transmission ratio between gears Z2 (5) and Z4 (6) is 1. Gear Z3 (7) is a reversing wheel. The shaft of gear Z4 (6) is connected to the input shaft of the slip adjustment device (8) via a coupling. The output shaft of the slip adjustment device (8) is connected to the... The clutch 2 (12) is connected, and the gear set B (14) is connected to the other end of the clutch 2 (12). The gear set B (14) includes gears Z5 (15) and Z6 (18) that mesh with each other. The transmission ratio of gears Z5 (15) and Z6 (18) is 1 / 3. One end of gear Z6 (18) is connected to the moment of inertia disk (16) through a universal joint, and the other end is connected to the simulated wheel sample (20). The left side of the simulated wheel sample (20) is connected to the encoder 1 (19). Vertical force loading device (13) Gear Z5 (15) and gear Z6 (18) are connected to each other via bearings. Gear Z2 (5) is connected to clutch 1 (28). Clutch 1 (28) is connected to torque sensor (23) via a coupling. Torque sensor (23) is connected to simulated rail sample (21). The right side of simulated rail sample (21) is connected to encoder 2 (22). Gear set C (25) is connected to the left side of clutch 1 (28). Gear set C (25) includes meshing gears Z7 (27) and Z8 (28). 26), gear Z8 (26) is connected to brake (24) via coupling; slip adjustment device (8) includes planetary gear differential and loading motor (9); vertical force loading device (13) includes: movable rod (1301) connected to gear Z5 (15) shaft and gear Z6 (18) shaft via bearing, loading electric cylinder (1307) is mounted on frame (17), and force sensor (1302) is installed on top of loading electric cylinder telescopic rod to detect the magnitude of vertical force loaded on simulated wheel sample.

2. The simulated adhesion test method of the multifunctional wheel-rail adhesion creep testing machine as described in claim 1, characterized in that, During the simulated adhesion test, the moment of inertia disk (16) is not connected, clutch 1 (28) and clutch 2 (12) are closed, and the drive motor (1), gear Z2 (5), gear Z3 (7), gear Z4 (6), slip adjustment device (8), vertical force loading device (13), gear set B (14), encoder 1 (19), encoder 2 (22), simulated wheel (20), simulated rail (21), and torque sensor (23) constitute a closed system. The slip adjustment device (8) has a transmission ratio of 3, the gear set B (14) has a transmission ratio of 1 / 3, and the total transmission ratio of the entire mechanical closed system is 1. At the beginning of the test, the speed control drive motor (1) is used to make the simulated wheel sample (20) and the simulated rail sample (21)... Rotating at a constant speed, the loading electric cylinder (1307) is controlled to apply a constant force between the wheel and rail samples. After the system stabilizes, the torque of the loading motor (9) is continuously adjusted to induce creep between the wheel and rail for wheel-rail adhesion test. The torque sensor (23) is used to measure the tangential force between the simulated wheel sample (20) and the simulated rail sample (21), and the force sensor (1302) is used to measure the magnitude of the loading normal force. The wheel-rail tangential force divided by the wheel-rail normal force is the wheel-rail adhesion coefficient. The encoder 1 (19) and encoder 2 (22) are used to measure the rotational speed of the wheel and rail samples, and the rotational speed difference between the wheel and rail samples is calculated. The creep rate is obtained by dividing the rotational speed difference by the rotational speed of the simulated wheel sample. Finally, the wheel-rail adhesion-creep characteristic curve is displayed by the data acquisition and processing system.

3. The simulated parking braking test method of a multifunctional wheel-rail adhesion creep testing machine as described in claim 1, characterized in that, During the simulated parking brake test, the brake (24) and gear Z8 (26) are connected by a coupling, and the moment of inertia disk (16) and gear Z6 (18) are connected by a universal joint. The drive motor (1) operates the entire system at a constant speed in speed control mode, and the loading cylinder (1307) applies a constant force between the wheel and rail samples. After the system stabilizes, clutch 1 (28) and clutch 2 (12) disengage, the drive motor (1) stops running, and the brake (24) is energized to input the braking torque, simulating the parking brake process. The wheel-rail adhesion-creep characteristic curve is displayed by the data acquisition and processing system.

4. The method for simulating uniform speed braking on a long downhill slope using a multifunctional wheel-rail adhesion creep testing machine as described in claim 1, characterized in that... During the simulated long downhill constant speed braking test, the brake (24) and gear Z8 (26) shaft are connected by a coupling, and the moment of inertia disk (16) and gear Z6 (18) are connected by a universal joint. The drive motor (1) operates the entire system at a constant speed in speed control mode. The loading cylinder (1307) applies a constant force between the wheel and rail sample. After the system stabilizes, clutch 1 (28) disengages and clutch 2 (12) closes. The drive motor (1) simulates the acceleration of the train along the slope direction in torque control mode. The brake (24) inputs braking torque to make the train run at a constant speed, simulating the downhill constant speed braking process. The wheel-rail adhesion-creep characteristic curve is displayed by the data acquisition and processing system.

5. The method for simulating a long uphill uniform speed traction test using a multifunctional wheel-rail adhesion creep testing machine as described in claim 1, characterized in that, During the simulated long uphill uniform speed traction test, the brake (24) and gear Z5 (15) are connected by a coupling, and the rotational inertia disk (16) and gear Z6 (18) are connected by a universal joint. The drive motor (1) operates the entire system at a certain speed in speed control mode, and controls the loading cylinder (1307) to apply a constant force between the wheel and rail sample. After the system stabilizes, the clutch 1 (28) is closed and the clutch 2 (12) is disengaged. The drive motor (1) simulates the traction force required for the train to go uphill in torque control mode. The brake (24) inputs braking torque to simulate the resistance encountered by the train during the uphill process, so that the train runs at a uniform speed and simulates the uniform speed uphill traction process of the train. The wheel-rail adhesion-creep characteristic curve is displayed by the data acquisition and processing system.

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