System for testing disc scratching problem of brake disc and test result evaluation standard

Abstract

The invention provides a system for testing a disc scratching problem of a brake disc and a test result evaluation standard. The test system extracts control parameters based on road spectrums generated by actual measurement of a real vehicle on a mountain road section and a highway section, and then generates a test program. The testing system comprises a temperature box, a driving motor, a connecting flange, a brake caliper assembly, a spraying device and a ventilation device, and the spraying device is used for spraying brake calipers and a brake disc so as to adjust humidity and accelerate reproduction of the scratching problem of the brake disc. Eight dimensions are adopted as final evaluation bases: the maximum depth of grooves in the surface of the brake disc, the surface roughness of the brake disc, the number of the grooves in the surface of the brake disc, the shape of metal deposits on the surface of the friction plate, the number of the metal deposits on the surface of the friction plate, the length of the metal deposits on the surface of the friction plate and the stripping area of friction plate materials on the surface of the friction plate. Therefore, the problem of scratching of the brake disc on a real vehicle can be predicted more accurately.

Description

Technical Field

[0001] The invention relates to the technical field of automobile testing, and in particular to a system for testing brake disc scratching problems and a test result evaluation standard. Background Art

[0002] The brake disc scratching problem refers to the friction between the brake disc and the friction pad during braking. The brake disc material is scraped and gathered on the surface of the friction pad. As more and more metal accumulates on the surface of the friction pad and falls off under the action of braking force, it eventually causes the material on the surface of the friction pad to fall off.

[0003] The problem of brake disc scratching can cause braking noise in the whole vehicle, leading to strong complaints from users. At present, the problem is not verified enough during the development of brake discs. The main reason is that the more accurate actual vehicle verification cycle is long and the cost is high; and the bench test currently used in the industry is insufficient and cannot accurately predict the performance of brake discs on actual vehicles. The current industry uses a combination of bench verification and actual vehicle verification to solve this technical problem. The main reason is that the prediction accuracy of bench verification is insufficient, so it relies more on actual vehicle verification.

[0004] The test benches currently used in the industry cannot truly reflect the user's operating conditions; the setting of test parameters does not take into account the impact of humidity on the occurrence of the scratching problem; and the test evaluation standards cannot accurately predict the performance of the actual vehicle.

[0005] In view of the above problems, the inventors of the present invention finally obtained the present invention after a long period of research and practice. Summary of the invention

[0006] In order to solve at least one of the above technical problems, the present invention provides a system for testing the brake disc scratching problem and a test result evaluation standard, which can shorten the verification cycle, reduce the verification cost, and help identify this problem in the early stage of development and formulate optimization measures.

[0007] The technical solution adopted by the present invention is:

[0008] In one aspect, a system for testing a brake disc scratching problem is provided, comprising a temperature chamber, a drive motor, a connecting flange, a brake caliper assembly, a spray device, and a ventilation device;

[0009] The drive motor, the connection flange and the brake caliper assembly are arranged in the temperature box; the temperature box is used to ensure that the ambient temperature inside it is not affected by external changes; the drive motor is used to drive the connection flange to rotate, the connection flange is used to install the brake disc to be tested, and the brake caliper assembly is used to provide brake clamping force to the brake disc during testing; the air inlet of the ventilation device is located in the temperature box, and is used to adjust the temperature in the temperature box;

[0010] The water spraying port of the spraying device is located in the temperature box, and is used to spray the brake caliper and the brake disc to adjust the humidity and accelerate the reproduction of the brake disc scratching problem.

[0011] Furthermore, the spray device also includes a water tank, a water pump, a water inlet channel and a drainage channel. The water pump serves as a power source to pump water in the water tank into the water inlet channel. The outlet of the water inlet channel is a water spray port. The drainage channel is connected to the bottom of the temperature box.

[0012] Furthermore, the ventilation device also includes a power device, an air inlet channel and an air outlet channel. The power device sends external airflow into the temperature box through the air inlet channel and discharges the airflow through the air outlet channel.

[0013] Furthermore, the system for testing the brake disc scratching problem also includes an inertia flywheel mechanism, which is arranged in the temperature box, and the inertia flywheel mechanism is connected between the drive motor and the connecting flange. The inertia flywheel mechanism includes a plurality of inertia flywheels connected in series, and the inertia changes required by different vehicle models are met by a combination of different inertia flywheels.

[0014] Furthermore, the system for testing the brake disc scratching problem also includes an emergency brake flywheel, which is arranged in the temperature box, and the emergency brake flywheel is connected between the drive motor and the inertia flywheel mechanism.

[0015] Furthermore, the system for testing the brake disc scratching problem also includes a brake hydraulic device, and the brake hydraulic device is connected to the brake caliper assembly.

[0016] Furthermore, the system for testing the brake disc scratching problem also includes a control device, which is electrically connected to the drive motor, the water pump, the power unit and the brake hydraulic unit; the control device controls the drive motor, the water pump, the power unit and the brake hydraulic unit according to a test procedure.

[0017] Furthermore, the system for testing the brake disc scratching problem also includes extracting control parameters based on a road spectrum generated by actual measurements of an actual vehicle on a mountain road section and a highway section, and then generating a test program.

[0018] Furthermore, the control parameters extracted based on the road spectrum include vehicle speed, brake oil pressure, brake disc temperature, travel direction, braking mode, cooling wind speed, number of braking times, and mileage.

[0019] Furthermore, the mountain road section is selected as a section with low braking pressure and continuous braking, and the high-speed road section is selected as a section in an area with high temperature and humidity.

[0020] Furthermore, the control parameters also include humidity, and the control device adjusts the humidity by controlling the water pump, and the number of spraying is set according to the number of braking times.

[0021] On the other hand, a test result evaluation standard based on the above system is provided, with the following 8 dimensions as the final evaluation basis:

[0022] 1. Maximum depth of the groove on the brake disc surface;

[0023] 2. Brake disc surface roughness;

[0024] 3. Number of grooves on the brake disc surface;

[0025] 4. The shape of metal deposits on the friction plate surface;

[0026] 5. The amount of metal deposits on the friction plate surface;

[0027] 6. Length of metal deposits on the friction plate surface;

[0028] 7. The area of ​​friction plate material peeling off on the friction plate surface;

[0029] 8. The depth of peeling of friction plate material on the friction plate surface.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] After analyzing the main operating conditions of the complaining users, the present invention collects data from Xiuning Mountain Road and Foshan Expressway to generate a road spectrum as the input of the test bench, thereby truly reflecting the operating conditions of the complaining users; adding a spray device during the verification process and taking humidity as one of the controlled variables can accelerate the reproduction of the problem; based on the road spectrum and test methods, an evaluation standard is formulated to more accurately predict the brake disc scratching problem on the actual vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic structural diagram of a testing device according to an embodiment of the present invention is shown;

[0034] Figure 2 The figure shows the parameter information extracted from the road spectra of Xiuningshan Road section and Foshan Expressway section selected in one embodiment of the present invention. DETAILED DESCRIPTION

[0035] The above and other technical features and advantages of the present invention are described in more detail below in conjunction with the accompanying drawings.

[0036] As used herein, the term "including" and its variations mean open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "based at least in part on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". Other explicit and implicit definitions may also be included below.

[0037] like Figure 1 As shown, in one embodiment, a system for testing the problem of brake disc scratching includes a temperature box 22, and the temperature box 22 is arranged on a base 19. The temperature box 22 is a relatively closed environment, which is used to ensure the stability of the test environment temperature and is not affected by external changes. The temperature box 22 is provided with a drive motor 17, a connecting flange 9, a brake caliper assembly 8, an inertia flywheel mechanism, and an emergency brake flywheel 15. The drive motor 17 is installed in the temperature box 22 through a drive motor support 18. The output end of the drive motor 17 is connected to the emergency brake flywheel 15 and the inertia flywheel mechanism in sequence. The emergency brake flywheel 15 is used for emergency braking. When the equipment fails, the emergency brake flywheel 15 is used to urgently stop the equipment. The inertia flywheel supports 11 and 16 are used to support the inertia flywheel mechanism through bearings. The drive motor 17 is used to drive the inertia flywheel mechanism to rotate. The inertia flywheel mechanism includes three inertia flywheels 12, 13, and 14 connected in series. The combination of different flywheels can support the inertia changes required by different vehicle models.

[0038] The inertia flywheel mechanism is connected to the connecting flange 9 through the coupling 11. The connecting flange 9 is used to install the brake disc 7 to be tested and is connected to the brake disc 7 through bolt connection. The brake caliper assembly 8 is installed on the brake caliper assembly mounting frame 6. The brake caliper assembly 8 is used to provide brake clamping force to the brake disc during testing. The brake caliper assembly 9 contains a friction plate. During braking, the brake disc 7 and the friction plate rub against each other. The brake caliper assembly mounting frame support 5 is used to support the brake caliper assembly mounting frame 6 through a bearing. The brake caliper assembly mounting frame limit block 4 is used for the lateral limit of the brake caliper assembly mounting frame 6. The brake caliper assembly 8 is connected to the brake hydraulic device 23. The brake hydraulic device 23 controls the brake caliper clamping force by controlling the amount and pressure of hydraulic oil.

[0039] The test system also includes a ventilation device for adjusting the temperature. The ventilation device includes a power device (not shown in the figure), an air inlet channel 3 and an air outlet channel 20. The outlet (air inlet) of the air inlet channel 3 is located in the temperature box 22. The power device sends the external airflow into the temperature box 22 through the air inlet channel 3 and discharges the airflow through the air outlet channel 20.

[0040] The test system also includes a spray device, which includes a water tank 1, a water pump (not shown in the figure), a water inlet channel 2 and a drainage channel 24. The water pump serves as a power source to pump water in the water tank 1 into the water inlet channel 2. The outlet of the water inlet channel 2 is a water spray port. The drainage channel 21 is connected to the bottom of the temperature box 22. The water spray port is located in the temperature box 22 and is used to spray the brake caliper and the brake disc to adjust the humidity and accelerate the reproduction of the brake disc scratching problem.

[0041] The test system also includes a control device, which is electrically connected to the drive motor, water pump, power unit and brake hydraulic unit. The control device controls the drive motor, water pump, power unit and brake hydraulic unit according to the test program. The control device controls the brake disc speed and brake caliper clamping force by controlling the drive motor and brake hydraulic unit; and controls the water pump and power unit to ensure that the temperature and humidity in the test environment meet the test requirements.

[0042] The test program of the test system is based on the road spectrum generated by actual measurements of the real vehicle on mountain roads and highways. The mountain roads select sections with low braking pressure and continuous braking, and the highways select sections in areas with high temperature and humidity. The control parameters are extracted from the road spectrum to generate the test program, and the control device is used to execute the test program. The control parameters extracted based on the road spectrum include vehicle speed, brake oil pressure, brake disc temperature, travel direction, braking mode, cooling wind speed, number of brakes, and mileage. The control parameters also include humidity. The control device adjusts the humidity by controlling the water pump, and the number of sprays is set according to the number of brakes.

[0043] like Figure 2 As shown, in a specific embodiment, the road spectrum generated by the Xiuning Mountain Road section and the Foshan Expressway section is used. One cycle is: first test the mountain road section, then test the expressway section. The test process needs to complete 5 complete cycles, the total number of braking times is 3815 times, and the actual mileage is about 1000km. Water is sprayed once every 100 braking times, and the single water spraying volume is greater than 1L.

[0044] The present invention formulates corresponding evaluation standards based on the adopted test procedures and test equipment, and observes, measures and records the friction pad surface and brake disc surface from the following 8 dimensions:

[0045] ① Maximum depth of the groove on the brake disc surface;

[0046] ② Surface roughness of the brake disc;

[0047] ③The number of grooves on the brake disc surface;

[0048] ④The shape of metal deposits on the friction plate surface;

[0049] ⑤The amount of metal deposits on the friction plate surface;

[0050] ⑥ Length of metal deposits on the friction plate surface;

[0051] ⑦ The area of ​​friction plate material peeling off on the friction plate surface;

[0052] ⑧ The depth of peeling of friction plate material on the friction plate surface.

[0053] Based on the above 8 dimensions as the final evaluation basis, the surface conditions of the brake disc and friction pad are scored on a 10-point scale. A final score of 7 points or above means that the part meets the requirements, and the higher the score, the better the test result.

[0054] The above are only preferred embodiments of the present invention, which are only illustrative and not restrictive. The structures and connection modes of the components in the present invention can be changed, and any equivalent transformations and improvements based on the technical solution of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A system for testing brake disc scratching problems, characterized in that: It includes a temperature box, a drive motor, a connecting flange, a brake caliper assembly, a spray device and a ventilation device; The drive motor, the connection flange and the brake caliper assembly are arranged in the temperature box; the temperature box is used to ensure that the ambient temperature inside it is not affected by external changes; the drive motor is used to drive the connection flange to rotate, the connection flange is used to install the brake disc to be tested, and the brake caliper assembly is used to provide brake clamping force to the brake disc during testing; the air inlet of the ventilation device is located in the temperature box, and is used to adjust the temperature in the temperature box; The water spraying port of the spraying device is located in the temperature box, and is used to spray the brake caliper and the brake disc to adjust the humidity and accelerate the reproduction of the brake disc scratching problem.

2. A system for testing brake disc scratching problems as claimed in claim 1, characterized in that: The spray device also includes a water tank, a water pump, a water inlet channel and a drainage channel. The water pump serves as a power source to pump water in the water tank into the water inlet channel. The outlet of the water inlet channel is a water spray port. The drainage channel is connected to the bottom of the temperature box.

3. A system for testing brake disc scratching problems as claimed in claim 2, characterized in that: The ventilation device also includes a power device, an air inlet channel and an air outlet channel. The power device sends external airflow into the temperature box through the air inlet channel and exhausts the airflow through the air outlet channel.

4. A system for testing brake disc scratching problems as claimed in claim 1, characterized in that: It also includes an inertia flywheel mechanism, which is arranged in the temperature box. The inertia flywheel mechanism is connected between the drive motor and the connecting flange. The inertia flywheel mechanism includes a plurality of inertia flywheels connected in series. The inertia changes required by different vehicle models can be met through the combination of different inertia flywheels.

5. A system for testing brake disc scratching problems as claimed in claim 1, characterized in that: It also includes an emergency brake flywheel, which is arranged in the temperature box, and the emergency brake flywheel is connected between the drive motor and the inertia flywheel mechanism.

6. A system for testing brake disc scratching problems as claimed in claim 3, characterized in that: It also includes a brake hydraulic device, which is connected to the brake caliper assembly.

7. A system for testing brake disc scratching problems as claimed in claim 6, characterized in that: It also includes a control device, which is electrically connected to the drive motor, the water pump, the power unit and the brake hydraulic device; the control device controls the drive motor, the water pump, the power unit and the brake hydraulic device according to a test procedure.

8. A system for testing brake disc scratching problems as claimed in claim 7, characterized in that: Based on the road spectra generated by actual measurements of a real vehicle on mountain roads and highways, control parameters are extracted to generate the test program.

9. A system for testing brake disc scratching problems as claimed in claim 8, characterized in that: The control parameters extracted based on the road spectrum include vehicle speed, brake oil pressure, brake disc temperature, travel direction, braking mode, cooling wind speed, number of brakes, and mileage.

10. A system for testing brake disc scratching problems as claimed in claim 9, characterized in that: The mountain road section is selected as a section with low braking pressure and continuous braking, and the high-speed road section is selected as a section in an area with high temperature and humidity.

11. A system for testing brake disc scratching problems as claimed in claim 9, characterized in that: The control parameters also include humidity. The control device adjusts the humidity by controlling the water pump, and the number of spraying is set according to the number of braking times.

12. A test result evaluation standard based on the system according to any one of claims 1 to 11, characterized in that: The following 8 dimensions are used as the final evaluation basis:

1. Maximum depth of the groove on the brake disc surface; 2. Surface roughness of brake disc; 3. Number of grooves on the brake disc surface; 4. The shape of metal deposits on the friction plate surface; 5. The amount of metal deposits on the friction plate surface; 6. Length of metal deposits on the friction plate surface; 7. The area of ​​friction plate material peeling off on the friction plate surface; 8. The depth of peeling of friction plate material on the friction plate surface.

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