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QC/T 239-2015: Specifications and bench test methods for commercial vehicle service brake Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid QC/T 239: Historical versions
QC/T 239-2015: Specifications and bench test methods for commercial vehicle service brake---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/QCT239-2015T24 INDUSTRY STANDARD QC/T 239-2015 Replacing QC/T 239-1997 and QC/T 479-1999 Specifications and Bench Test Methods for Commercial Vehicle Service Brake Issued on. APRIL 30, 2015 Implemented on. OCTOBER 1, 2015 Issued by Ministry of Industry and Information Technology of the People's Republic of China QC Table of ContentsForeword... I 1 Scope... 1 2 Normative References... 1 3 Terminologies and Definitions... 1 4 Performance Requirements... 4 5 Relevant Requirements for Test... 6 6 Test Preparation... 7 7 Test Methods and Conditions... 8 Appendix A (Normative) Evaluation Method of Braking Torque... 141 ScopeThis standard specifies the terminologies and definitions, performance requirements as well as bench test methods of commercial vehicle service brake assembly. This standard applies to the service brake assembly for Categories M2, M3 and N vehicles specified in GB/T 15089 as well as friction lining (brake block) assembly. The brake assembly for Category O vehicles may also refer to the provisions of this standard.2 Normative ReferencesThe following documents for the application of this document are essential. Any dated reference, just dated edition applies to this standard. For undated references, the latest edition (including any amendments) applies to this standard. GB/T 5620 Road Vehicles - Braking of Automotive Vehicles and Their Trailers – Vocabulary GB/T 15089 Classification of Power - Driven Vehicles and Trailers QC/T 556 Automotive Brake - Temperature Measurement and Thermocouple Attachment3 Terminologies and DefinitionsFor the purposes of this standard, the terminologies and definitions specified in GB/T 5620 and the following ones apply. 3.1 Braking period The time from stating a braking to the next braking in a continuous braking procedure. Note. braking period is expressed in second (s). 3.2 Initial braking temperature The temperature of brake drum (disc) or friction lining (brake block) at the beginning of braking. Note. initial braking temperature is expressed in ℃. 3.3 Average braking torque The ordinate value obtained by dividing the area enclosed by braking torque and braking time by the active braking time during a braking, see Appendix A. Note. average braking torque is expressed in N·m. 3.4 Maximum braking torque The maximum value of braking torque on longitudinal coordinate on the curve changing with braking time within the active braking time during a braking, see Mmax in Appendix A. Note. the maximum braking torque is expressed in N·m.4 Performance Requirements4.1 Brake performance test 4.1.1 The first efficiency test. 4.1.2 The first normal temperature efficiency test. Tested according to 7.1.4, the average braking torque value of its sample under the specified braking pressure shall not be less than 75 % of the average braking torque value under the same braking pressure of the corresponding initial braking speed in the second efficiency test. 4.1.3 The second efficiency test. 4.1.3.1 Tested according to 7.1.5, when the initial braking speed is 60km/h (80km/h for Category N1 vehicles), the average braking torque value of its sample under the specified braking pressure shall be within the design upper and lower limits, when design upper and lower limits are not required, it shall be within the scope of 90% ~ 120%; the stability for braking torque shall not be less than 0.80. 4.1.4 The first fade recover test. 4.1.4.1 Tested according to 7.1.7, the fade rate of its sample shall be within the scope of -20 % ~ 40%, and the absolute value of the recover rate shall not be larger than 20%. 4.1.4.2 The average braking torque value of thermal braking efficiency test shall not be less than 60% of that under the equivalent conditions in the second efficiency test. 4.1.4.3 At the end of the test, brake shall work normally, and shall not have obvious dragging. 4.1.5 The third efficiency test. The same as 4.1.3. 4.1.6 The second fade test. 4.1.7 The second normal temperature efficiency test. The average braking torque value of sample under the specified braking pressure shall not be less than 75% of the average braking torque value under the same braking pressure in the fourth efficiency test. 4.1.8 The fourth efficiency test. The same as 4.1.3. 4.1.9 Braking noise requirements. During the test process in 7.1, when measurement is conducted according to 5.2.4, the braking noise of the samples for Categories M2, M3 and N1 vehicles shall be less than 80dB (A), while that of the samples for other categories shall be less than 85dB(A). 4.2 Brake wear test 4.2.1 Wear requirements. 4.2.1.1 The wear requirements for brake friction lining (brake block) and brake drum (disc) shall be subject to negotiation between supplier and purchaser. 4.2.1.2 After the whole wear test is finished, friction lining (brake block) and brake drum (disc) shall meet the following requirements. 4.2.2 Braking efficacy inspection. Compared with that before wear test, the average braking torque variation under the specified braking pressure shall not exceed ±15%.5 Relevant Requirements for Test5.1 Test equipment requirements 5.1.1 The test equipment is inertia brake test bench (both single-wheel and double-wheel are allowed), its performance index shall meet the requirements of all tests in this standard. 5.1.4 The control error of braking pressure, braking torque and rotation speed of test bench main shaft shall not be larger than ±3%. The relative error of rotational inertia (including the inertia of test bench rotating part) shall not be larger than ±5%. 5.1.5 The test equipment shall be able to continuously record the following parameters, and the measuring error shall meet the following requirements. 5.1.6 The device and thermocouple used for measuring the temperature of brake drum (disc) or friction lining (brake block) shall meet the relevant requirements of QC/T 556. 5.1.7 For the instruments or meters indicating various parameters, the accuracy grade shall not be lower than Grade 2.5. 5.2 Other requirements 5.2.1 All test speeds shall be rounded off to the integral multiple of 5. 5.2.2 Except for fade test and unless otherwise specified, the test cooling air velocity shall be 11 m/s, and the temperature of cooling air shall be the room temperature. 5.2.3 Unless otherwise specified, the braking final velocity of all tests shall be zero. 5.2.4 During braking noise measurement, the sound pickup of sound level meter shall be placed at the place within the rotation plane of the tested brake 500mm away from the right above of brake rotation axis, and the sound pickup shall be installed in wind ball.6 Test Preparation6.1 Thermocouple shall be installed according to the relevant requirements in QC/T 556. 6.2 The rotation speed of test bench main shaft shall be converted according to Formula (6).7 Test Methods and Conditions7.1 Brake performance test 7.1.1 Inspection prior to running-in. 7.1.2 The first efficiency test. 7.1.2.1 The initial braking temperature is (80±2)℃. 7.1.2.2 For Category N1 vehicles, the initial braking speed is 50 km/h or 80 km/h; for other categories of vehicles, it is 30km/h or 60 km/h. 7.1.3 The first running-in test. 7.1.3.1 The initial braking temperature shall not be larger than 120℃. 7.1.3.2 The initial braking speed is 50 km/h. 7.1.3.3 For Category N1 and Category M2 vehicles, the braking deceleration is 3.5m/s2; for other categories of vehicles, it is 3.0m/s2. 7.1.4 The first normal temperature efficiency test. 7.1.4.1 The initial braking temperature shall not be larger than 50℃. 7.1.4.2 For Category N1 vehicles, the initial braking speed is 50 km/h; for other categories of vehicle, it is 30 km/h. 7.1.4.3 The braking pressure is the same as that in the first efficiency test. 7.1.4.4 Record the initial braking speed, initial braking temperature, braking final temperature, braking time, braking pressure and output braking torque of each braking. 7.1.5 The second efficiency test. For vehicles with the maximum design speed less than 90 km/h, it's the same as 7.1.2. For vehicles with the maximum design speed larger than or equal to 90 km/h, the initial braking speed shall be increased by 80% Vmax (it shall not be greater than 120 km/h for Category N1 vehicles; it shall not be greater than 100 km/h for Category M2 and Category N2 vehicles; it shall not be greater than 90 km/h for Category M3 and Category N3 vehicles), the rest is the same as 7.1.2. 7.1.6 The second running-in test. The braking times is 50, the rest is the same as 7.1.3. 7.1.7 The first fade recover test. 7.1.7.1 Reference test. 7.1.7.2 Fade test. 7.1.7.4 Recover test a) For Category N1 and Category M2 vehicles, the initial braking speed is 50 km/h; for other categories of vehicles, it is 30 km/h. b) The braking pressure is the same as that in the reference test. c) The braking period is 60 s. d) The braking times is 15.If the initial braking temperature of the last recover test is higher than 100℃, braking times may be added, however, the total braking times shall not be larger than 20. 7.2.4 Wear test. Wear test conditions are shown in Table 3.At the end of each temperature grade test, measure the friction lining (brake block) thickness according to 7.2.2, and calculate its wear, which is the arithmetic mean of each measuring point. 7.2.5 Braking efficiency inspection. At the end of the wear test, running-in test shall be conducted according to 7.1.6, then efficiency test shall be conducted according to 7.1.5.Appendix A(Normative) Evaluation Method of Braking Torque Schematic diagrams for brake test process and braking torque value are shown in Figure A.1 and Figure A.2. ICS 43.040.40 T24 INDUSTRY STANDARD QC/T 239-2015 Replacing QC/T 239-1997 and QC/T 479-1999 Specifications and Bench Test Methods for Commercial Vehicle Service Brake Issued on. APRIL 30, 2015 Implemented on. OCTOBER 1, 2015 Issued by Ministry of Industry and Information Technology of the People's Republic of China QCTable of ContentsForeword... I 1 Scope... 1 2 Normative References... 1 3 Terminologies and Definitions... 1 4 Performance Requirements... 4 5 Relevant Requirements for Test... 6 6 Test Preparation... 7 7 Test Methods and Conditions... 8 Appendix A (Normative) Evaluation Method of Braking Torque... 141 ScopeThis standard specifies the terminologies and definitions, performance requirements as well as bench test methods of commercial vehicle service brake assembly. This standard applies to the service brake assembly for Categories M2, M3 and N vehicles specified in GB/T 15089 as well as friction lining (brake block) assembly. The brake assembly for Category O vehicles may also refer to the provisions of this standard.2 Normative ReferencesThe following documents for the application of this document are essential. Any dated reference, just dated edition applies to this standard. For undated references, the latest edition (including any amendments) applies to this standard. GB/T 5620 Road Vehicles - Braking of Automotive Vehicles and Their Trailers – Vocabulary GB/T 15089 Classification of Power - Driven Vehicles and Trailers QC/T 556 Automotive Brake - Temperature Measurement and Thermocouple Attachment3 Terminologies and DefinitionsFor the purposes of this standard, the terminologies and definitions specified in GB/T 5620 and the following ones apply. 3.1 Braking period The time from stating a braking to the next braking in a continuous braking procedure. Note. braking period is expressed in second (s). 3.2 Initial braking temperature The temperature of brake drum (disc) or friction lining (brake block) at the beginning of braking. Note. initial braking temperature is expressed in ℃. 3.3 Average braking torque The ordinate value obtained by dividing the area enclosed by braking torque and braking time by the active braking time during a braking, see Appendix A. Note. average braking torque is expressed in N·m. 3.4 Maximum braking torque The maximum value of braking torque on longitudinal coordinate on the curve changing with braking time within the active braking time during a braking, see Mmax in Appendix A. Note. the maximum braking torque is expressed in N·m.4 Performance Requirements4.1 Brake performance test 4.1.1 The first efficiency test. 4.1.2 The first normal temperature efficiency test. Tested according to 7.1.4, the average braking torque value of its sample under the specified braking pressure shall not be less than 75 % of the average braking torque value under the same braking pressure of the corresponding initial braking speed in the second efficiency test. 4.1.3 The second efficiency test. 4.1.3.1 Tested according to 7.1.5, when the initial braking speed is 60km/h (80km/h for Category N1 vehicles), the average braking torque value of its sample under the specified braking pressure shall be within the design upper and lower limits, when design upper and lower limits are not required, it shall be within the scope of 90% ~ 120%; the stability for braking torque shall not be less than 0.80. 4.1.4 The first fade recover test. 4.1.4.1 Tested according to 7.1.7, the fade rate of its sample shall be within the scope of -20 % ~ 40%, and the absolute value of the recover rate shall not be larger than 20%. 4.1.4.2 The average braking torque value of thermal braking efficiency test shall not be less than 60% of that under the equivalent conditions in the second efficiency test. 4.1.4.3 At the end of the test, brake shall work normally, and shall not have obvious dragging. 4.1.5 The third efficiency test. The same as 4.1.3. 4.1.6 The second fade test. 4.1.7 The second normal temperature efficiency test. The average braking torque value of sample under the specified braking pressure shall not be less than 75% of the average braking torque value under the same braking pressure in the fourth efficiency test. 4.1.8 The fourth efficiency test. The same as 4.1.3. 4.1.9 Braking noise requirements. During the test process in 7.1, when measurement is conducted according to 5.2.4, the braking noise of the samples for Categories M2, M3 and N1 vehicles shall be less than 80dB (A), while that of the samples for other categories shall be less than 85dB(A). 4.2 Brake wear test 4.2.1 Wear requirements. 4.2.1.1 The wear requirements for brake friction lining (brake block) and brake drum (disc) shall be subject to negotiation between supplier and purchaser. 4.2.1.2 After the whole wear test is finished, friction lining (brake block) and brake drum (disc) shall meet the following requirements. 4.2.2 Braking efficacy inspection. Compared with that before wear test, the average braking torque variation under the specified braking pressure shall not exceed ±15%.5 Relevant Requirements for Test5.1 Test equipment requirements 5.1.1 The test equipment is inertia brake test bench (both single-wheel and double-wheel are allowed), its performance index shall meet the requirements of all tests in this standard. 5.1.4 The control error of braking pressure, braking torque and rotation speed of test bench main shaft shall not be larger than ±3%. The relative error of rotational inertia (including the inertia of test bench rotating part) shall not be larger than ±5%. 5.1.5 The test equipment shall be able to continuously record the following parameters, and the measuring error shall meet the following requirements. 5.1.6 The device and thermocouple used for measuring the temperature of brake drum (disc) or friction lining (brake block) shall meet the relevant requirements of QC/T 556. 5.1.7 For the instruments or meters indicating various parameters, the accuracy grade shall not be lower than Grade 2.5. 5.2 Other requirements 5.2.1 All test speeds shall be rounded off to the integral multiple of 5. 5.2.2 Except for fade test and unless otherwise specified, the test cooling air velocity shall be 11 m/s, and the temperature of cooling air shall be the room temperature. 5.2.3 Unless otherwise specified, the braking final velocity of all tests shall be zero. 5.2.4 During braking noise measurement, the sound pickup of sound level meter shall be placed at the place within the rotation plane of the tested brake 500mm away from the right above of brake rotation axis, and the sound pickup shall be installed in wind ball.6 Test Preparation6.1 Thermocouple shall be installed according to the relevant requirements in QC/T 556. 6.2 The rotation speed of test bench main shaft shall be converted according to Formula (6).7 Test Methods and Conditions7.1 Brake performance test 7.1.1 Inspection prior to running-in. 7.1.2 The first efficiency test. 7.1.2.1 The initial braking temperature is (80±2)℃. 7.1.2.2 For Category N1 vehicles, the initial braking speed is 50 km/h or 80 km/h; for other categories of vehicles, it is 30km/h or 60 km/h. 7.1.3 The first running-in test. 7.1.3.1 The initial braking temperature shall not be larger than 120℃. 7.1.3.2 The initial braking speed is 50 km/h. 7.1.3.3 For Category N1 and Category M2 vehicles, the braking deceleration is 3.5m/s2; for other categories of vehicles, it is 3.0m/s2. 7.1.4 The first normal temperature efficiency test. 7.1.4.1 The initial braking temperature shall not be larger than 50℃. 7.1.4.2 For Category N1 vehicles, the initial braking speed is 50 km/h; for other categories of vehicle, it is 30 km/h. 7.1.4.3 The braking pressure is the same as that in the first efficiency test. 7.1.4.4 Record the initial braking speed, initial braking temperature, braking final temperature, braking time, braking pressure and output braking torque of each braking. 7.1.5 The second efficiency test. For vehicles with the maximum design speed less than 90 km/h, it's the same as 7.1.2. For vehicles with the maximum design speed larger than or equal to 90 km/h, the initial braking speed shall be increased by 80% Vmax (it shall not be greater than 120 km/h for Category N1 vehicles; it shall not be greater than 100 km/h for Category M2 and Category N2 vehicles; it shall not be greater than 90 km/h for Category M3 and Category N3 vehicles), the rest is the same as 7.1.2. 7.1.6 The second running-in test. The braking times is 50, the rest is the same as 7.1.3. 7.1.7 The first fade recover test. 7.1.7.1 Reference test. 7.1.7.2 Fade test. 7.1.7.4 Recover test a) For Category N1 and Category M2 vehicles, the initial braking speed is 50 km/h; for other categories of vehicles, it is 30 km/h. b) The braking pressure is the same as that in the reference test. c) The braking period is 60 s. d) The braking times is 15.If the initial braking temperature of the last recover test is higher than 100℃, braking times may be added, however, the total braking times shall not be larger than 20. 7.2.4 Wear test. Wear test conditions are shown in Table 3.At the end of each temperature grade test, measure the friction lining (brake block) thickness according to 7.2.2, and calculate its wear, which is the arithmetic mean of each measuring point. 7.2.5 Braking efficiency inspection. At the end of the wear test, running-in test shall be conducted according to 7.1.6, then efficiency test shall be conducted according to 7.1.5.Appendix A(Normative) Evaluation Method of Braking Torque Schematic diagrams for brake test process and braking torque value are shown in Figure A.1 and Figure A.2. ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of English version of QC/T 239-2015 be delivered?Answer: The full copy PDF of English version of QC/T 239-2015 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice.Question 2: Can I share the purchased PDF of QC/T 239-2015_English with my colleagues?Answer: Yes. 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