A test apparatus and method for train disc brakes considering wheel-rail creep.

Abstract

This invention discloses a test apparatus and method for train disc brakes considering wheel-rail creep. The apparatus includes a test bench base, a fixed gantry, a track simulation system, an axle load system, a disc brake system, and a control system. The fixed gantry is fixedly mounted on the test bench base, the axle load system is fixedly mounted above the test bench base via the fixed gantry, the disc brake system is fixedly mounted on the axle load system, and the track simulation system is mounted on the test bench base and rolls in contact with the axle load system. This invention enables the analysis of the braking performance of the disc brake system under wheel-rail creep conditions, as well as the dynamic response when multiple brake discs brake simultaneously. It thus provides an in-depth exploration of the braking characteristics of the disc brake system under wheel-rail creep conditions and the complex coupling mechanism between the braking system and the wheel and rail.

Description

Technical Field

[0001] This invention relates to the field of friction and vibration technology, and in particular to a test device and method for train disc brakes that takes into account wheel-rail creep. Background Technology

[0002] During the operation of rail transit vehicles, the braking system plays a crucial role in ensuring driving safety. Traditional braking systems may experience performance degradation under high speeds and complex operating conditions, while disc brake systems, due to their superior heat dissipation and braking efficiency, have become the preferred solution for improving train braking safety. Specifically, disc brakes play an indispensable role in rail transit vehicles of different types and operating environments, providing a solid and reliable guarantee for the safe stopping of the vehicle.

[0003] Wheel-rail creep refers to the relative slippage between the wheels and rails during train braking due to changes in friction. When the train's braking system applies torque, a small amount of slippage occurs between the wheels and rails due to friction; this phenomenon is called creep. Appropriate creep helps ensure effective contact between the wheels and rails during braking, thereby improving braking efficiency. However, excessive creep can lead to wear on the wheel and rail surfaces, unstable braking response, and safety hazards. The occurrence of creep is influenced by various factors, including the material properties of the wheels and rails, the shape of the contact surfaces, the magnitude of the applied force, and the operating conditions. This phenomenon is extremely important in train operation, directly affecting braking performance and safety.

[0004] While current braking test apparatuses provide crucial support for performance evaluation and development, many suffer from limitations in fully simulating real-world operating conditions, particularly in accurately reflecting wheel-rail creep. These apparatuses are typically based on fixed experimental conditions, failing to effectively simulate the complex dynamic interactions between wheels and rails during actual operation, especially creep. This makes it difficult to consider this critical factor when designing and improving braking systems. Furthermore, existing apparatuses have limitations in the number of braking devices they can accommodate, restricting research on the dynamic characteristics of multiple brake discs braking simultaneously. Additionally, these apparatuses cannot effectively investigate the impact of wheel-rail creep on braking systems in different installation positions. Summary of the Invention

[0005] To address the problem that existing braking test devices cannot fully simulate the actual wheel-rail creep phenomenon under real operating conditions, this invention proposes a train disc brake test device and method that takes wheel-rail creep into account, thus solving the above problem.

[0006] This application discloses a train disc brake test device that takes into account wheel-rail creep, including a test bench base, a fixed gantry, a track simulation system, an axle load system, a disc brake system, and a control system. The fixed gantry is fixedly mounted on the test bench base, the axle load system is fixedly mounted above the test bench base via the fixed gantry, the disc brake system is fixedly mounted on the axle load system, and the track simulation system is mounted on the test bench base and makes rolling contact with the axle load system.

[0007] Preferably, the track simulation system includes a motor, a coupling, a reducer, track wheels, and an axle. The motor drives the axle to rotate sequentially through the motor shaft, coupling, and reducer. Two track wheels are symmetrically arranged at both ends of the axle, with a distance of 1435mm between them. By precisely controlling the frictional contact, not only is the frictional force stable, but the wheel-rail contact of the train during braking is also effectively simulated, thus accurately reproducing the wheel-rail creep effect.

[0008] Preferably, the track wheel is made of rail steel and has multiple through holes inside, with a curved tread surface. This structure provides a larger contact area for wheel-rail creep, helps to distribute local pressure between the wheel and rail, makes the transmission of friction more uniform, reduces wear and fatigue, and improves the durability of the wheel and rail.

[0009] Preferably, the axle load system includes wheels, axles, hydraulic devices, and suspension devices. The axles are fixedly mounted on a fixed gantry by bolts. Two wheels are symmetrically mounted at both ends of the axles and contact the track wheels below. Hydraulic devices are symmetrically mounted at the ends of the axles and are fixedly mounted on the fixed gantry by the suspension devices.

[0010] Preferably, the wheel is made of low-carbon high-strength alloy steel, the tread is a wear-resistant tread, and the outer edge of the wheel is provided with a bevel or arc shape for guidance and to reduce wear. It is connected to the rim by spokes or a solid structure to ensure that it reproduces the actual train running state during the simulation.

[0011] Preferably, it includes multiple disc brake systems, which are equidistantly arranged on the axle.

[0012] Preferably, the disc brake system includes a brake disc, brake pads, brake calipers, cylinders, and suspension equipment. The brake pads are symmetrically arranged on both sides of the brake disc and fixed to the suspension equipment by the brake calipers. Cylinders are mounted on the brake calipers, and the cylinders are connected to an air pump via air pipes. The suspension equipment is fixedly mounted on a fixed mast. Using brake calipers enables rapid braking response, improving driving safety and maneuverability. Furthermore, the design can be diversified to adapt to the needs of different types of trains and can be optimized according to performance indicators.

[0013] Preferably, the brake pad adopts a combined brake pad structure, which is composed of multiple minimum friction units. A polygonal friction block is selected as the minimum friction unit, and the polygonal friction block is manufactured by powder metallurgy.

[0014] Preferably, the control system includes a track simulation system control system, an axle load system control system, and a disc brake system control system.

[0015] This application also discloses a test method for train disc brakes that takes into account wheel-rail creep, using the aforementioned test device for train disc brakes that take into account wheel-rail creep, including the following steps:

[0016] S1. Install brake pads and sensors;

[0017] S2. Set the working quantity of the disc brake system;

[0018] S3. Set the axle load pressure, motor speed and cylinder braking pressure in the control system;

[0019] S4. Send a pressurization signal to the axle load system to apply pressure to the wheels through a hydraulic device to simulate axle load;

[0020] S5. The drive motor rotates, which in turn drives the coupling, reducer, axle and track wheel to rotate in sequence. The track wheel drives the wheel and brake disc to rotate in sequence through friction.

[0021] S6. Transmit braking commands to the disc brake system and select the braking mode;

[0022] S7. Send a pressure signal to the cylinder of the disc brake system, which drives the brake caliper to rotate, so that the brake pads contact the brake disc.

[0023] The beneficial effects of this invention are:

[0024] 1. This invention utilizes the frictional contact between the wheelset and the rail wheel during braking to generate wheel-rail creep, enabling the analysis of the braking performance of a disc brake system under wheel-rail creep conditions. Furthermore, the wheel-rail relationship possesses high flexibility and adjustability; through the control system, the simulated wheel-rail contact conditions, such as wheel-rail clearance and contact angle, can be easily adjusted to achieve different wheel-rail creep states.

[0025] 2. This invention utilizes three disc brake systems with brake discs mounted at specific intervals on the axle to effectively balance the forces applied to the wheelset. This results in more uniform mechanical characteristics during braking, avoiding force concentration issues that may occur in traditional braking systems, and improving the response speed and stability of the braking system. Furthermore, each system includes an independent power unit, allowing different braking strategies to be used by each system, and enabling analysis of the dynamic response when multiple braking systems brake simultaneously. Further, the impact of wheel-rail creep on disc brake systems at different positions can be investigated.

[0026] 3. This invention applies pressure to the wheel axle through the axle load system to simulate the actual axle load of the train. It can simulate the axle load range of the train from empty to fully loaded. Moreover, this simulation includes not only static load but also dynamic load changes, which provides the possibility for studying the performance of the braking system under different load conditions.

[0027] 4. During train braking, this invention utilizes a combination of sensors, including acceleration and temperature sensors mounted on the brake pads and noise sensors near the track wheels, to monitor the wheelset's condition in real time. This includes crucial data such as temperature, pressure, speed, and wear levels of the wheelset and braking system. Simultaneously, the system allows operators to dynamically adjust braking force and braking method based on real-time monitoring results. Through real-time detection and adjustment of each braking process, more intelligent and precise train braking control can be achieved.

[0028] 5. By understanding the braking characteristics and behavioral features of disc brake systems under wheel-rail creep, this invention can provide guidance for the next step of optimizing the design of disc brake systems and further improve the braking performance of disc brake systems. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a train disc brake test device considering wheel-rail creep according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the orbit simulation system structure according to an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the axle load system structure according to an embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of the hydraulic device structure according to an embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of the interaction between the track wheel and the wheelset in an embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of the disc braking system structure according to an embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of the brake pad structure according to an embodiment of the present invention.

[0036] The attached figures are labeled as follows:

[0037] 1-Test bench base, 2-Fixed gantry, 3-Railway simulation system, 301-Motor, 302-Coupling, 303-Reducer, 304-Railway wheel, 305-Wheel axle, 4-Axle load system, 401-Wheel, 402-Axle, 403-Hydraulic device, 404-Suspension device, 5-Disc brake system, 501-Brake disc, 502-Brake pad, 503-Brake caliper, 504-Cylinder, 505-Suspension equipment, 6-Control system. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided with reference to the accompanying drawings and embodiments.

[0039] Example 1

[0040] Embodiment 1 of this application discloses a train disc brake test device that takes into account wheel-rail creep, such as Figure 1 As shown, the system includes a test bench base 1, a fixed gantry 2, a track simulation system 3, an axle load system 4, a disc brake system 5, and a control system 6. The fixed gantry 2 is fixedly mounted on the test bench base 1 by bolts. The axle load system 4 is fixedly mounted on the test bench base 1 above the test bench base 1 by the four columns of the fixed gantry 2. The disc brake system 5 is fixedly mounted on the axle 402 of the axle load system 4. The track simulation system 3 is mounted on the test bench base 1 and rolls in contact with the wheel 401 of the axle load system 4.

[0041] like Figure 2 As shown, the track simulation system 3 includes a motor 301, a coupling 302, a reducer 303, track wheels 304, and axle 305. The motor 301 drives the axle 305 to rotate sequentially through the motor shaft, coupling 302, and reducer 303. Two track wheels 304 are symmetrically arranged at both ends of the axle 305, with a distance of 1435mm between them. By precisely controlling the frictional contact, not only is the frictional force stable, but the wheel-rail contact of the train during braking is also effectively simulated, thus accurately reproducing the wheel-rail creep effect.

[0042] The track wheel 304 is made of rail steel and has multiple through holes inside. The tread curvature of the track wheel 304 is 5°. This structure provides a larger contact area for wheel-rail creep, helps to distribute local pressure between the wheel and rail, makes the transmission of friction more uniform, reduces wear and fatigue, and improves the durability of the wheel and rail.

[0043] like Figures 3-5 As shown, the axle load system 4 includes wheels 401, axles 402, hydraulic devices 403, and suspension devices 404. The axles 402 are fixedly mounted on the fixed gantry 2 by bolts. Two wheels 401 are symmetrically arranged at both ends of the axles 402 and contact the track wheels 304 below. Hydraulic devices 403 are symmetrically arranged at the ends of the axles 402. The hydraulic devices 403 are fixedly mounted on the fixed gantry 2 by the suspension devices 404.

[0044] Wheel 401 is made of low-carbon high-strength alloy steel. The tread is a wear-type tread. The outer edge of wheel 401 is provided with a bevel or arc shape for guidance and to reduce wear. It is connected to the rim by spokes or a solid structure to ensure that it reproduces the actual train running state during the simulation.

[0045] like Figure 6 As shown, the disc brake system 5 includes a brake disc 501, brake pads 502, brake calipers 503, cylinders 504, and suspension equipment 505. The brake pads 502 are symmetrically arranged on both sides of the brake disc 501 and fixed to the suspension equipment 505 by the brake calipers 503. Cylinders 504 are mounted on the brake calipers, and the cylinders 504 are connected to an air pump via air pipes. The suspension equipment 505 is fixedly mounted on the fixed gantry 2. Using the brake calipers 503 enables rapid braking response, improving driving safety and maneuverability. Furthermore, the design can be diversified to adapt to the needs of different types of trains and can be optimized according to performance indicators. Figure 7 As shown, the brake pad 502 adopts a combined brake pad structure, which consists of multiple minimum friction units, with a polygonal friction block selected as the minimum friction unit. The polygonal friction block is manufactured using powder metallurgy to optimize friction performance and heat dissipation.

[0046] In this embodiment, there are three disc brake systems 5, which are equidistantly arranged on the axle 402. Each system includes an independent power unit, allowing each system to use a different braking strategy. Furthermore, it effectively balances the forces applied to the wheelset, facilitates the collection and observation of the interaction between the discs, and results in more uniform mechanical characteristics during braking, thereby reducing wheelset wear, extending its service life, and improving the reliability of the test results.

[0047] The control system includes a track simulation system control system, an axle load system control system, and a disc brake system control system. The track simulation system control system controls the speed of motor 301, driving the track wheels 304 to rotate, thus simulating different vehicle speeds. The axle load system control system controls the hydraulic device 403 to apply pressure to the suspension device 404, which is then transmitted to the axle 402, simulating actual axle load. The disc brake system control system controls the air pressure in cylinder 504 to control the braking force of the brake pads 502. During braking, the control system utilizes a combination of sensors, including acceleration and temperature sensors mounted on the brake pads and noise sensors near the track wheels, to comprehensively capture the dynamic response of the wheelset. These sensors transmit the collected data to the central processing unit, where processing and analysis reveal the vibration amplitude, frequency characteristics, and noise level of the wheelset under different braking conditions.

[0048] Using the train disc brake test device considering wheel-rail creep proposed in Example 1, a train disc brake test considering wheel-rail creep was conducted. The specific test methods are shown in Examples 2-5.

[0049] Example 2

[0050] Using the train disc brake test device considering wheel-rail creep proposed in Example 1, a braking experiment of the disc brake device under wheel-rail excitation was conducted, specifically including the following steps:

[0051] S1. Install brake pads 502, acceleration sensor, temperature sensor and noise sensor.

[0052] S2, Set the disc brake system 5 command to operate 3 disc brake systems 5 simultaneously.

[0053] S3. In the control system, the axle load pressure is set to 10 tons, the motor speed is set to 20 km / h, and the braking pressure of cylinder 503 is set to 18 kN.

[0054] S4. Send a pressurization signal to the axle load system 4, and apply pressure to the wheel 401 through the hydraulic device 403. Set the pressure to 10 tons to simulate a test under a 10-ton load.

[0055] S5. The drive motor 301 rotates, which in turn drives the coupling 302, reducer 303, wheel axle 305 and track wheel 304 to rotate in sequence. The track wheel 304 drives the wheel 401 and brake disc 501 to rotate in sequence through friction. The drive stops after the speed reaches 20km / h.

[0056] S6. Transmit braking command to disc brake system 5, and select 3 disc brake systems 5 to work simultaneously.

[0057] S7. A pressure signal is sent to the cylinder 504 of the disc brake system 5, which drives the brake caliper 503 to rotate, so that the brake pad 502 contacts the brake disc 501, and the braking pressure is set to 18kN.

[0058] Example 3

[0059] Using the train disc brake test device considering wheel-rail creep as proposed in Example 1, a drag braking test of the disc brake device under wheel-rail creep was conducted, specifically including the following steps:

[0060] S1. Install brake pads 502, acceleration sensor, temperature sensor and noise sensor.

[0061] S2, Set the disc brake system 5 command to operate 3 disc brake systems 5 simultaneously.

[0062] S3. In the control system, the axle load pressure is set to 12 tons, the motor speed is set to 20 km / h, and the braking pressure of cylinder 503 is set to 15 kN.

[0063] S4. Send a pressurization signal to the axle load system 4, and apply pressure to the wheel 401 through the hydraulic device 403. Set the pressure to 10 tons to simulate a test under a 12-ton load.

[0064] S5. The drive motor 301 rotates, which in turn drives the coupling 302, reducer 303, wheel axle 305 and track wheel 304 to rotate in sequence. The track wheel 304 drives the wheel 401 and brake disc 501 to rotate in sequence through friction. The speed is set to 20km / h and a constant speed is maintained during braking to achieve a towing effect.

[0065] S6. Transmit braking command to disc brake system 5, and select 3 disc brake systems 5 to work simultaneously.

[0066] S7. A pressure signal is sent to the cylinder 504 of the disc brake system 5, which drives the brake caliper 503 to rotate, so that the brake pad 502 contacts the brake disc 501, and the braking pressure is set to 15kN.

[0067] Example 4

[0068] Using the train disc brake test device considering wheel-rail creep proposed in Example 1, braking tests were conducted on different numbers of disc brake systems under wheel-rail creep conditions. The specific steps included:

[0069] S1. Install brake pads 502, acceleration sensor, temperature sensor and noise sensor.

[0070] S2. Set the disc brake system 5 to work as a single disc brake system 5 for 5 minutes, and then add the remaining disc brake systems 5 in sequence at 5-minute intervals, so that all 3 disc brake systems work at the same time.

[0071] S3. In the control system, the axle load pressure is set to 15 tons, the motor speed is set to 20 km / h, and the braking pressure of cylinder 503 is set to 18 kN.

[0072] S4. Send a pressurization signal to the axle load system 4, and apply pressure to the wheel 401 through the hydraulic device 403. Set the pressure to 10 tons to simulate a test under a 15-ton load.

[0073] S5. The drive motor 301 rotates, which in turn drives the coupling 302, reducer 303, wheel axle 305 and track wheel 304 to rotate in sequence. The track wheel 304 drives the wheel 401 and brake disc 501 to rotate in sequence through friction. The speed is set to 20km / h and a constant speed is maintained during braking to achieve a towing effect.

[0074] S6. A braking command is transmitted to the disc brake system 5. Initially, a single disc brake system 5 operates for 5 minutes, and the remaining disc brake systems 5 are added sequentially at 5-minute intervals, until all three disc brake systems operate simultaneously.

[0075] S7. A pressure signal is sent to the cylinder 504 of the disc brake system 5, which drives the brake caliper 503 to rotate, so that the brake pad 502 contacts the brake disc 501, and the braking pressure is set to 18kN.

[0076] Example 5

[0077] Using the train disc brake test device considering wheel-rail creep proposed in Example 1, a disc brake system under wheel-rail creep axle load variation braking experiment was conducted, specifically including the following steps:

[0078] S1. Install brake pads 502, acceleration sensor, temperature sensor and noise sensor.

[0079] S2, Set the disc brake system 5 command to operate 3 disc brake systems 5 simultaneously.

[0080] S3. In the control system, the axle load pressure is set to gradually decrease from 17 tons to 3 tons, the deceleration is 1 ton / minute, the motor speed is 20 km / h, and the braking pressure of cylinder 503 is 18 kN.

[0081] S4. Send a pressurization signal to the axle load system 4, and apply pressure to the wheel 401 through the hydraulic device 403. Set the pressure to gradually decrease from 17 tons to 3 tons, and the deceleration to 1 ton / minute to simulate the braking test under axle load change.

[0082] S5. The drive motor 301 rotates, which in turn drives the coupling 302, reducer 303, wheel axle 305 and track wheel 304 to rotate in sequence. The track wheel 304 drives the wheel 401 and brake disc 501 to rotate in sequence through friction. The speed is set to 20km / h and a constant speed is maintained during braking to achieve a towing effect.

[0083] S6. A braking command is transmitted to the disc brake system 5. Initially, a single disc brake system 5 operates for 5 minutes, and the remaining disc brake systems 5 are added sequentially at 5-minute intervals, until all three disc brake systems operate simultaneously.

[0084] S7. A pressure signal is sent to the cylinder 504 of the disc brake system 5, which drives the brake caliper 503 to rotate, so that the brake pad 502 contacts the brake disc 501, and the braking pressure is set to 18kN.

[0085] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A test method for train disc brakes considering wheel-rail creep, characterized in that, The test is conducted using a test apparatus comprising a test bench base (1), a fixed gantry (2), a track simulation system (3), an axle load system (4), a disc brake system (5), and a control system (6). The fixed gantry (2) is fixedly mounted on the test bench base (1), the axle load system (4) is fixedly mounted above the test bench base (1) via the fixed gantry (2), the disc brake system (5) is fixedly mounted on the axle load system (4), and the track simulation system (3) is mounted on the test bench base (1) and rolls in contact with the axle load system (4). The track simulation system (3) includes a motor (301), a coupling (302), a reducer (303), track wheels (304), and axle (305). The motor (301) is connected in sequence to the motor shaft, coupling (302), reducer (303), and axle (305). Two track wheels (304) are symmetrically arranged at both ends of the axle (305). The axle load system (4) includes wheels (401), axles (402), hydraulic devices (403) and suspension devices (404). The axles (402) are fixedly mounted on the fixed gantry (2). Two wheels (401) are symmetrically mounted at both ends of the axles (402) and in contact with the track wheels (304). Hydraulic devices (403) are symmetrically mounted at the ends of the axles (402). The hydraulic devices (403) are fixedly mounted on the fixed gantry (2) through the suspension devices (404). The disc brake system (5) includes multiple sets, and the multiple sets of disc brake systems are equally spaced on the axle (402); The disc brake system (5) includes a brake disc (501), brake pads (502), brake calipers (503), cylinders (504), and suspension devices (505). The brake pads (502) are symmetrically arranged on both sides of the brake disc (501) and fixed to the suspension devices (505) by the brake calipers (503). The cylinders (504) are installed on the brake calipers. The cylinders (504) are connected to an air pump through an air pipe. The suspension devices (505) are fixedly installed on the fixed mast (2). The train disc brake test method includes the following steps: S1. Install brake pads (502) and sensors; S2, Set the working quantity of the disc brake system (5); S3. Set the axle load pressure, motor speed and cylinder (504) braking pressure in the control system; S4. A pressurization signal is sent to the axle load system (4), and pressure is applied to the wheel (401) through the hydraulic device (403) to simulate the axle load; S5. The drive motor (301) rotates, which in turn drives the coupling (302), reducer (303), wheel axle (305) and track wheel (304) to rotate in sequence. The track wheel (304) drives the wheel (401) and brake disc (501) to rotate in sequence through friction. S6. Transmit braking commands to the disc brake system, select all disc brake systems to work simultaneously, or select a single disc brake system to work, maintain for 5 minutes, and add the remaining disc brake systems in sequence at 5-minute intervals, until all disc brake systems work simultaneously. S7. A pressure signal is sent to the cylinder (504) of the disc brake system (5), which drives the brake caliper (503) to rotate, so that the brake pad (502) contacts the brake disc (501).

2. The test method for train disc brakes considering wheel-rail creep according to claim 1, characterized in that, The track wheel (304) is made of steel rail steel and has multiple through holes inside. The tread of the track wheel (304) is curved.

3. The test method for train disc brakes considering wheel-rail creep according to claim 2, characterized in that, The wheel (401) is made of low-carbon high-strength alloy steel, and the tread is a wear-type tread. The outer edge of the wheel (401) is provided with a slope or arc shape, and the wheel rim is connected by spokes or a solid structure.

4. The test method for train disc brakes considering wheel-rail creep according to claim 3, characterized in that, The brake pad (502) adopts a combined brake pad structure, which is composed of multiple minimum friction units. A polygonal friction block is selected as the minimum friction unit, and the polygonal friction block is manufactured by powder metallurgy.

5. The test method for train disc brakes considering wheel-rail creep according to claim 4, characterized in that, The control system includes a track simulation system control system, an axle load system control system, and a disc brake system control system.

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