Method for testing re-clamping performance of hot disc of electronic integrated disc brake

Abstract

The invention relates to the technical field of brake systems, in particular to a method for testing the re-clamping performance of a hot disc of an electronic integrated disc brake. The invention discloses a method for testing the re-clamping performance of a hot disc of an electronic integrated disc brake. The method specifically comprises the following steps: S1, determining static friction coefficients of a brake disc and a friction plate at different temperatures; s2, the attenuation of the parking clamping force at different temperatures is determined; s3, calculating a re-clamping time matrix under different brake disc temperatures and different parking gradients; s4, verifying whether the parking clamping force reserve meets the requirement or not under the re-clamping time matrix calculated in the step S3 on an inertia table; s5, according to the re-clamping matrix range of the test points, if it is judged that the test points are in a non-re-clamping range, the step S6 is continued; if the test point is in the re-clamping range, skipping to the step S13; s6, determining that the test point is in a non-re-clamping range and the like. Compared with the prior art, the method can be used for verifying the re-clamping performance of the hot disc of the electronic integrated disc brake.

Description

Technical Field

[0001] The invention relates to the technical field of brake systems, in particular to a test method for hot disc re-clamping performance of an electronic integrated disc brake. Background Art

[0002] The electronic integrated disc brake has both conventional hydraulic braking functions and an electronic parking brake function (Electric Park Brake, EPB), which is an emerging automotive electronic control technology. The electronic parking brake system replaces the traditional mechanical levers and tire cables, and can provide better assistance to the driver. It is safer than the traditional lever handbrake, can achieve safe parking under all working conditions, and will not change the braking effect due to the driver's strength. At the same time, since the electronic parking brake system eliminates the handbrake lever, there will be no interference between the zipper and the gearbox, and the interior design of the vehicle is more flexible. In addition, the electronic parking brake system also has the advantages of comfort, light weight and volume, enhanced functions and networking, making it more and more used.

[0003] There are two main technologies for applying electronic parking brake systems on vehicles: cable-type and caliper-integrated. Compared with the cable-type structure, the actuator of the caliper-integrated structure is integrated into the rear axle brake caliper, and the traditional zipper has been eliminated. However, no matter which method is used, the electronic control unit (ECU) of the electronic parking brake system needs to communicate externally with the electronic stability control system (ESC) of the vehicle through the CAN bus.

[0004] The integrated structure of the caliper is mainly composed of a housing, a bracket, inner and outer friction plates, a piston, a ball screw, and a gearbox assembly. After a series of braking actions, the temperature of the brake disc will rise. If the vehicle is parked on a road with a certain slope at this time, the temperature of the brake disc will drop over time. According to the principle of thermal expansion and contraction, the thickness of the brake disc will shrink as the temperature drops, which will cause a decrease in the clamping force. Especially when the temperature of the vehicle's brake disc is relatively high and the vehicle is parked on a slope with a large slope, the decrease in clamping force caused by the cooling of the brake disc may make the parking torque unable to keep the vehicle on the slope, so a method is needed to verify the performance of the electronic integrated disc brake hot disc re-clamp (HDR). Summary of the invention

[0005] The invention overcomes the shortcomings of the prior art and provides a test method for the hot disc re-clamping performance of an electronic integrated disc brake. The method can verify the hot disc re-clamping performance of the electronic integrated disc brake.

[0006] In order to achieve the above purpose, a test method for the hot disc re-clamping performance of an electronic integrated disc brake is designed, including a brake caliper assembly and a brake disc, and is characterized in that: the specific method is as follows:

[0007] S1, determine the static friction coefficient between the brake disc and the friction pad at different temperatures;

[0008] S2, determine the attenuation of the parking clamping force at different temperatures;

[0009] S3, calculate the re-clamping time matrix under different brake disc temperatures and different parking slopes;

[0010] S4, verifying on the inertia platform whether the parking clamping force reserve meets the requirements under the re-clamping time matrix calculated in step S3;

[0011] S5, judging according to the matrix range of the test point re-clamping, if the test point is in the non-re-clamping range, then proceeding to step S6; if the test point is in the re-clamping range, then jumping to step S13;

[0012] S6, the test point is in the non-re-clamping range;

[0013] S7, when the brake disc temperature reaches 250°C, the nominal clamping force is applied by the electronic integrated brake caliper drive motor, and then the reverse torque M+5% is applied by the inertia table auxiliary motor;

[0014] S8, natural cooling, the inertia table does not blow cooling air until the disc temperature cools to room temperature, monitors the rotation signal of the brake disc during the cooling process, and further determines whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceed to step S9, otherwise jump to step S10;

[0015] S9, if the equivalent distance of wheel rotation is >10cm, the test is terminated;

[0016] S10, if the equivalent distance of wheel rotation is less than 10cm, whether the reverse torque increases to M+10%, further determine whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceed to step S11, otherwise jump to step S12;

[0017] S11, the torque applied by the brake motor is increased to M+10% and maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is >10cm, the test is terminated;

[0018] S12, the torque applied by the brake motor is increased to M+10% and maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is less than 10 cm, the reverse torque is continuously increased after 30 minutes until the equivalent distance of wheel rotation is greater than 10 cm, then the test is stopped and the torque value M0 at this time is recorded;

[0019] S13, the test point is in the re-clamping range;

[0020] S14, when the brake disc temperature reaches the test temperature, the nominal clamping force is applied by the electronic integrated brake caliper drive motor, and the nominal torque M is applied by the inertia table auxiliary motor, and the re-clamping action is implemented within 600 seconds according to the calculated re-clamping matrix;

[0021] S15, after 600s, the nominal torque M+5% is applied through the inertia platform auxiliary motor;

[0022] S16, natural cooling, the inertia table does not blow cooling air until the disc temperature cools to room temperature, monitors the rotation signal of the brake disc during the cooling process, and further determines whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceeds to step S17, otherwise jumps to step S18;

[0023] S17, if the equivalent distance of wheel rotation is >10cm, the test is terminated;

[0024] S18, if the equivalent distance of wheel rotation is less than 10cm, whether the reverse torque increases to M+10%, further determine whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceed to step S19, otherwise jump to step S20;

[0025] S19, the torque applied by the inertia platform auxiliary motor increases to M+10% and is maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is >10cm, the test is terminated;

[0026] S20, the torque applied by the brake motor increases to M+10% and is maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is less than 10 cm, then after maintaining for 30 minutes, the reverse torque continues to increase until the equivalent distance of wheel rotation is greater than 10 cm, then the test stops and the torque value M0 at this time is recorded.

[0027] The specific process of step S1 is as follows:

[0028] S1-1, on the inertia table, the brake is heated according to a series of required temperatures;

[0029] S1-2, using hydraulic pressure to apply a clamping force Fcl corresponding to the design on the brake;

[0030] S1-3, use the inertia table motor to slowly apply reverse torque on the brake disc spindle until the brake disc starts to rotate, and record the current motor torque Mb;

[0031] S1-4, the static friction coefficient at the current temperature is calculated according to the formula;

[0032] S1-5, after the temperature sequence test is completed, the relationship curve between the static friction coefficient and the temperature is output;

[0033] The formula in step S1-4 is: Among them, μ start is the static friction coefficient, Mb is the torque applied by the motor to the main shaft of the brake disc when the brake disc starts to rotate, r eff is the effective friction radius of the friction plate, F cl It is the clamping force between the brake disc and the friction pad.

[0034] The specific process of step S2 is as follows:

[0035] S2-1, on the inertia table, the brake is heated according to a series of required temperatures;

[0036] S2-2, using the gearbox assembly to apply a designed clamping force on the brake;

[0037] S2-3, naturally cool the brake disc to 30°C, and record the process of clamping force attenuation during the cooling process;

[0038] S2-4, after the temperature sequence test is completed, the relationship curve between the clamping force, temperature and cooling time is output.

[0039] The series of required temperatures are 0-250°C, 1-250°C, 2-150°C, 3-250°C, 4-350°C, 5-350°C, 6-500°C, 7-500°C, and 8-500°C.

[0040] The matrix of step S3 is the relationship curve between the static friction coefficient and temperature obtained in step S1, and the relationship curve between the clamping force and the temperature and cooling time obtained in step S2, and the time matrix of re-clamping at different temperatures is calculated.

[0041] In step S4, the percentage of the parking clamping force reserve margin is M 储备 =Torque reserve M0, M 名义 = Required parking torque M for the slope req .

[0042] In step S5, the non-re-clamping range is that the disk temperature is within the range of 0 to 250°C and the slope is within the range of 0 to 20%; the re-clamping range: (1) the disk temperature is within the range of 0 to 150°C and the slope is within the range of 20 to 30%; (2) the disk temperature is within the range of 150 to 250°C and the slope is within the range of 20 to 30%; (3) the disk temperature is within the range of 250 to 350°C and the slope is within the range of 0 to 30%; (4) the disk temperature is within the range of 350 to 500°C and the slope is within the range of 0 to 20%.

[0043] Compared with the prior art, the present invention provides a test method for the hot disc re-clamping performance of an electronic integrated disc brake, and the method can verify the hot disc re-clamping performance of the electronic integrated disc brake. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a flow chart of the present invention.

[0045] Figure 2 is the relationship curve between the static friction coefficient and the temperature in step S1.

[0046] Figure 3 is a curve showing the relationship between the clamping force, temperature and cooling time in step S2.

[0047] Figure 4 It is a time matrix diagram of re-clamping at different temperatures in step S3.

[0048] Figure 5 This is the parking clamping force reserve margin map in step S4. DETAILED DESCRIPTION

[0049] The present invention will be further described below with reference to the accompanying drawings.

[0050] like Figure 1 As shown, a test method for hot disc re-clamping performance of an electronic integrated disc brake includes a brake caliper assembly and a brake disc. The specific method is as follows:

[0051] S1, determine the static friction coefficient between the brake disc and the friction pad at different temperatures;

[0052] S2, determine the attenuation of the parking clamping force at different temperatures;

[0053] S3, calculate the re-clamping time matrix under different brake disc temperatures and different parking slopes;

[0054] S4, verifying on the inertia platform whether the parking clamping force reserve meets the requirements under the re-clamping time matrix calculated in step S3;

[0055] S5, judging according to the matrix range of the test point re-clamping, if the test point is in the non-re-clamping range, then proceeding to step S6; if the test point is in the re-clamping range, then jumping to step S13;

[0056] S6, the test point is in the non-re-clamping range;

[0057] S7, when the brake disc temperature reaches 250°C, the nominal clamping force is applied by the electronic integrated brake caliper drive motor, and then the reverse torque M+5% is applied by the inertia table auxiliary motor;

[0058] S8, natural cooling, the inertia table does not blow cooling air until the disc temperature cools to room temperature, monitors the rotation signal of the brake disc during the cooling process, and further determines whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceed to step S9, otherwise jump to step S10;

[0059] S9, if the equivalent distance of wheel rotation is >10cm, the test is terminated;

[0060] S10, if the equivalent distance of wheel rotation is less than 10cm, whether the reverse torque increases to M+10%, further determine whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceed to step S11, otherwise jump to step S12;

[0061] S11, the torque applied by the brake motor is increased to M+10% and maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is >10cm, the test is terminated;

[0062] S12, the torque applied by the brake motor is increased to M+10% and maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is less than 10 cm, the reverse torque is continuously increased after 30 minutes until the equivalent distance of wheel rotation is greater than 10 cm, then the test is stopped and the torque value M0 at this time is recorded;

[0063] S13, the test point is in the re-clamping range;

[0064] S14, when the brake disc temperature reaches the test temperature, the nominal clamping force is applied by the electronic integrated brake caliper drive motor, and the nominal torque M is applied by the inertia table auxiliary motor, and the re-clamping action is implemented within 600 seconds according to the calculated re-clamping matrix;

[0065] S15, after 600s, the nominal torque M+5% is applied through the inertia platform auxiliary motor;

[0066] S16, natural cooling, the inertia table does not blow cooling air until the disc temperature cools to room temperature, monitors the rotation signal of the brake disc during the cooling process, and further determines whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceeds to step S17, otherwise jumps to step S18;

[0067] S17, if the equivalent distance of wheel rotation is >10cm, the test is terminated;

[0068] S18, if the equivalent distance of wheel rotation is less than 10cm, whether the reverse torque increases to M+10%, further determine whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceed to step S19, otherwise jump to step S20;

[0069] S19, the torque applied by the inertia platform auxiliary motor increases to M+10% and is maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is >10cm, the test is terminated;

[0070] S20, the torque applied by the brake motor increases to M+10% and is maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is less than 10 cm, then after maintaining for 30 minutes, the reverse torque continues to increase until the equivalent distance of wheel rotation is greater than 10 cm, then the test stops and the torque value M0 at this time is recorded.

[0071] like Figure 2 As shown, the specific process of step S1 is as follows:

[0072] S1-1, on the inertia table, the brake is heated according to a series of required temperatures;

[0073] S1-2, using hydraulic pressure to apply a clamping force Fcl corresponding to the design on the brake;

[0074] S1-3, use the inertia table motor to slowly apply reverse torque on the brake disc spindle until the brake disc starts to rotate, and record the current motor torque Mb;

[0075] S1-4, the static friction coefficient at the current temperature is calculated according to the formula;

[0076] S1-5, after the temperature sequence test is completed, the relationship curve between the static friction coefficient and the temperature is output;

[0077] The formula in step S1-4 is: Among them, μ start is the static friction coefficient, Mb is the torque applied by the motor to the main shaft of the brake disc when the brake disc starts to rotate, r eff is the effective friction radius of the friction plate, F cl It is the clamping force between the brake disc and the friction pad.

[0078] like Figure 3 As shown, the specific process of step S2 is as follows:

[0079] S2-1, on the inertia table, the brake is heated according to a series of required temperatures;

[0080] S2-2, using the gearbox assembly to apply a designed clamping force on the brake;

[0081] S2-3, naturally cool the brake disc to 30°C, and record the process of clamping force attenuation during the cooling process;

[0082] S2-4, after the temperature sequence test is completed, the relationship curve between the clamping force, temperature and cooling time is output.

[0083] A series of required temperatures are 0-250°C, 1-250°C, 2-150°C, 3-250°C, 4-350°C, 5-350°C, 6-500°C, 7-500°C, 8-500°C.

[0084] like Figure 4 As shown, the matrix of step S3 is the relationship curve between the static friction coefficient and temperature obtained in step S1, and the relationship curve between the clamping force and the temperature and cooling time obtained in step S2, and the time matrix of re-clamping at different temperatures is calculated.

[0085] like Figure 5 As shown, in step S4, the percentage of the parking clamping force reserve margin M 储备 =Torque reserve M0, M 名义 = Required parking torque M for the slope req .

[0086] In step S5, the non-re-clamping range is that the disk temperature is in the range of 0 to 250°C and the slope is in the range of 0 to 20%; the re-clamping range: (1) the disk temperature is in the range of 0 to 150°C and the slope is in the range of 20 to 30%; (2) the disk temperature is in the range of 150 to 250°C and the slope is in the range of 20 to 30%; (3) the disk temperature is in the range of 250 to 350°C and the slope is in the range of 0 to 30%; (4) the disk temperature is in the range of 350 to 500°C and the slope is in the range of 0 to 20%.

[0087] The method of the present invention can verify the hot disc re-gripping performance of the electronic integrated disc brake.

Claims

1. A test method for hot disc re-clamping performance of an electronic integrated disc brake, comprising a brake caliper assembly and a brake disc, characterized in that: The specific method is as follows: S1, determine the static friction coefficient between the brake disc and the friction pad at different temperatures; S2, determine the attenuation of the parking clamping force at different temperatures; S3, calculate the re-clamping time matrix under different brake disc temperatures and different parking slopes; S4, verifying on the inertia platform whether the parking clamping force reserve meets the requirements under the re-clamping time matrix calculated in step S3; S5, judging according to the matrix range of the test point re-clamping, if the test point is in the non-re-clamping range, then proceeding to step S6; if the test point is in the re-clamping range, then jumping to step S13; S6, the test point is in the non-re-clamping range; S7, when the brake disc temperature reaches 250°C, the nominal clamping force is applied by the electronic integrated brake caliper drive motor, and then the reverse torque M+5% is applied by the inertia table auxiliary motor; S8, natural cooling, the inertia table does not blow cooling air until the disc temperature cools to room temperature, monitors the rotation signal of the brake disc during the cooling process, and further determines whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceed to step S9, otherwise jump to step S10; S9, if the equivalent distance of wheel rotation is >10cm, the test is terminated; S10, if the equivalent distance of wheel rotation is less than 10cm, whether the reverse torque increases to M+10%, further determine whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceed to step S11, otherwise jump to step S12; S11, the torque applied by the brake motor is increased to M+10% and maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is >10cm, the test is terminated; S12, the torque applied by the brake motor is increased to M+10% and maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is less than 10 cm, the reverse torque is continuously increased after 30 minutes until the equivalent distance of wheel rotation is greater than 10 cm, then the test is stopped and the torque value M0 at this time is recorded; S13, the test point is in the re-clamping range; S14, when the brake disc temperature reaches the test temperature, the nominal clamping force is applied by the electronic integrated brake caliper drive motor, and the nominal torque M is applied by the inertia table auxiliary motor, and the re-clamping action is implemented within 600 seconds according to the calculated re-clamping matrix; S15, after 600s, the nominal torque M+5% is applied through the inertia platform auxiliary motor; S16, natural cooling, the inertia table does not blow cooling air until the disc temperature cools to room temperature, monitors the rotation signal of the brake disc during the cooling process, and further determines whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceeds to step S17, otherwise jumps to step S18; S17, if the equivalent distance of wheel rotation is >10cm, the test is terminated; S18, if the equivalent distance of wheel rotation is less than 10cm, whether the reverse torque increases to M+10%, further determine whether the equivalent distance of wheel rotation is greater than 10cm, if yes, proceed to step S19, otherwise jump to step S20; S19, the torque applied by the inertia platform auxiliary motor increases to M+10% and is maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is >10cm, the test is terminated; S20, the torque applied by the brake motor increases to M+10% and is maintained for 30 minutes, during which the rotation signal of the brake disc is monitored; if the equivalent distance of wheel rotation is less than 10 cm, then after maintaining for 30 minutes, the reverse torque continues to increase until the equivalent distance of wheel rotation is greater than 10 cm, then the test stops and the torque value M0 at this time is recorded.

2. The test method for hot disc re-gripping performance of electronic integrated disc brake according to claim 1, characterized in that: The specific process of step S1 is as follows: S1-1, on the inertia table, the brake is heated according to a series of required temperatures; S1-2, using hydraulic pressure to apply a clamping force Fcl corresponding to the design on the brake; S1-3, use the inertia table motor to slowly apply reverse torque on the brake disc spindle until the brake disc starts to rotate, and record the current motor torque Mb; S1-4, the static friction coefficient at the current temperature is calculated according to the formula; S1-5, after the temperature sequence test is completed, the relationship curve between the static friction coefficient and the temperature is output; The formula in step S1-4 is: Among them, μ start is the static friction coefficient, Mb is the torque applied by the motor to the main shaft of the brake disc when the brake disc starts to rotate, r eff is the effective friction radius of the friction plate, F cl It is the clamping force between the brake disc and the friction pad.

3. The test method for hot disc re-gripping performance of electronic integrated disc brake according to claim 1, characterized in that: The specific process of step S2 is as follows: S2-1, on the inertia table, the brake is heated according to a series of required temperatures; S2-2, using the gearbox assembly to apply a designed clamping force on the brake; S2-3, naturally cool the brake disc to 30°C, and record the process of clamping force attenuation during the cooling process; S2-4, after the temperature sequence test is completed, the relationship curve between the clamping force, temperature and cooling time is output.

4. The test method for hot disc re-gripping performance of electronic integrated disc brake according to claim 2 or 3, characterized in that: The series of required temperatures are 0-250°C, 1-250°C, 2-150°C, 3-250°C, 4-350°C, 5-350°C, 6-500°C, 7-500°C, and 8-500°C.

5. The test method for hot disc re-gripping performance of electronic integrated disc brake according to claim 1, characterized in that: The matrix of step S3 is the relationship curve between the static friction coefficient and temperature obtained in step S1, and the relationship curve between the clamping force and the temperature and cooling time obtained in step S2, and the time matrix of re-clamping at different temperatures is calculated.

6. The test method for hot disc re-gripping performance of electronic integrated disc brake according to claim 1, characterized in that: In step S4, the parking clamping force reserve margin M 储备 =Torque reserve M0, M 名义 = Required parking torque M for the slope req .

7. The test method for hot disc re-gripping performance of electronic integrated disc brake according to claim 1, characterized in that: In step S5, the non-re-clamping range is that the disk temperature is within the range of 0 to 250°C and the slope is within the range of 0 to 20%; the re-clamping range: (1) the disk temperature is within the range of 0 to 150°C and the slope is within the range of 20 to 30%; (2) the disk temperature is within the range of 150 to 250°C and the slope is within the range of 20 to 30%; (3) the disk temperature is within the range of 250 to 350°C and the slope is within the range of 0 to 30%; (4) the disk temperature is within the range of 350 to 500°C and the slope is within the range of 0 to 20%.

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