GB/T Translated English of Chinese Standard: GB/T Translated by:

Transcription

1 Translated English of Chinese Standard: GB/T Translated by: ICS National Standard of the People s Republic of China GB G 41 GB/T Replacing GB/T , GB/T , GB/T , GB/T Laboratory Test Methods for Passenger Car Tyres Capabilities (ISO 10191:1995 Passenger car tyres Verifying tyre capabilities - Laboratory test methods, MOD) Issue on: April 4, 2009 Implemented on: December 1, 2009 Jointly issued by: General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ); Standardization Administration (SAC) of the People's Republic of China. Page 1 of 22

2 Table of Contents Foreword Scope Normative references Terms and definitions Test equipment and precision Test methods Requirements Test report Annex A Annex B Page 2 of 22

3 Foreword This Standard modifies and adopts ISO 10191:1995 Passenger car tyres - Verifying tyre capabilities - Laboratory test methods (2 nd English edition). This Standard replaces GB/T Endurance test for passenger car tyres-drum method, GB/T Test method strength for passenger car tyres, GB/T Bead unseating resistance test for tubeless passenger car tyres, and GB/T High speed test for passenger car tyres-drum method. This Standard has been re-drafted according to ISO 10191:1995. GB/T Endurance test for passenger car tyres-drum method, GB/T Test method strength for passenger car tyres, GB/T Bead unseating resistance test for tubeless passenger car tyres, and GB/T High speed test for passenger car tyres-drum method have been integrated and revised. And methods for low-pressure performance test are added. Annex A provides a list of comparison between chapter and clause numbers of this Standard and ISO 10191:1995, in order to facilitate the comparison. The technical differences between this Standard and ISO 10191:1995 are marked with vertical single lines in the main text and the margins of pages where contain the clauses that involve these differences. Annex B lists out the technical differences and their causes for reference. The following editing changes are also made to this Standard, in order to facilitate the use: a) This International Standard is changed to This Standard ; b), used as the decimal point is replaced by. ; c) The foreword of the international standard is deleted; d) The bibliography of the international standard is deleted. Below are the main differences between the chapters and clauses of this Standard and GB/T : The arrangement of chapters and clauses are adjusted in this Standard; Added and modified Normative References (GB/T and 2 of this Standard); Added and modified precision requirements on the test equipment (4 and 7 of GB/T ; and 4 of this Standard); Modified requirements on the test rim (5.1.2 of GB/T ; and of this Standard); Modified the test inflation pressure of reinforced radial tyres and diagonal tyres of passenger cars (Table 1); Added the test inflation pressures for T Type temporary-use spare tyres (Table 1); Modified the test speed for radial tyres of passenger cars by changing it from 80km/h to 120km/h (5.1.4 of GB/T ; and of this Standard); Page 3 of 22

4 Modified the provision that the pressure shall be immediately measured after the test is completed. It is changed to be that the pressure shall be measured within a cooling period of (15~25) min (5.2.5 of GB/T ; and of this Standard); Deleted the requirement that the outer dimensions of the tyre shall be measured before and after the test (5.2.1 and of GB/T ); Added requirements on the judgment of test results, including that the pressure measures as required after the test shall not be lower than 95% of the initial pressure, and that no visual evidence of damages shall be found in appearance check (6.4 of this Standard); Modified and added requirements on the test report and its contents (7 of this Standard). Below are the main differences between the chapters and clauses of this Standard and GB/T : The arrangement of chapters and clauses is adjusted in this Standard; Modified requirements on the test rim (5.2 of GB/T ; and and of this Standard); Modified and added requirements on the test report and its contents (7 of this Standard). Below are the main differences between the chapters and clauses of this Standard and GB/T : The arrangement of chapters and clauses is adjusted in this Standard; Added and modified Normative References (2 of GB/T ; and 2 of this Standard); Modified requirements on the test tyre and its appearance (5.1.1 and of GB/T ; and of this Standard); Modified requirements on the test rim (5.1.2 of GB/T ; and of this Standard); Modified the test inflation pressure of reinforced radial tyres and diagonal tyres of passenger cars (Table 3 of GB/T ; and Table 1 of this Standard); Added the test inflation pressures and minimum bead unseating resistance for T Type temporary-use spare tyres (Table 1 and Table 7 of this Standard); Modified requirements on formula computation of p values of tyres of 65 and its following series and designated p values according to the normal diameters of rims of 4 categories (normal height/width ratio 55~80, 50/45, 40/35, 30/25). Added p values corresponding to the T Type temporary-use spare tyres and rims of normal diameters 20~28 (Table 2 of GB/T ; and Table 2 of this Standard); Added Type A bead unseating blocks which are specially used for T Type temporary use spare tyres and passenger car tyres of nominal rim diameters 10~19; and Type C bead unseating blocks which are specially used for passenger car tyres of nominal rim diameters 20~28 ( Figure 2 of this Standard); Modified and added requirements on the test report and its contents (7 of this Standard). Below are the main differences between the chapters and clauses of this Standard and GB/T : Page 4 of 22

5 The arrangement of chapters and clauses is adjusted in this Standard; Added and modified Normative References (GB/T and 2 of this Standard); Added and modified precision requirements on the test equipment (7 of GB/T ; and 4 of this Standard); Modified requirements on the test rim (5.1.2 of GB/T and of this Standard); Modified the specified values of test inflation pressure of radial tyres of speed symbols W and Y, 8PR diagonal tyres, and T Type temporary-use spare tyres (Table 1 of GB/T and Table 3 of this Standard); Deleted belted radial tyres (Table 1 of GB/T ; and Table 3 of this Standard); Modified the load rate for test of tyres of speed symbol H and below by changing it from 65% to 80%. Increased the load rates of tests of radial tyres of speed symbols W and Y (Table 2 of GB/T ; and Table 4 of this Standard); Added the test procedure for passenger car tyres of speed symbols W and Y (Table 2 of GB/T ; and Table 5 of this Standard); Modified the requirement that the pressure shall be immediately measured after the test is completed. It is changed to be that the pressure shall be measured within a cooling period of (15~25) min (5.2.5 of GB/T ; and of this Standard); Deleted the requirement that the outer dimensions of the tyre shall be measured before and after the test (5.2.1 and of GB/T ); Added requirements on the judgment of test results, including that the pressure measures as required after the test shall not be lower than 95% of the initial pressure, and that no visual evidence of damages shall be found in appearance check (6.3 of this Standard); Modified and added requirements on the test report and its contents (7 of this Standard). Annex A and Annex B of this Standard are normative. This Standard was proposed by China Petroleum & Chemical Industry Association. This Standard shall be centrally managed by SAC Technical Committee for Standardization of Tyres and Rim. Responsible drafting organizations of this Standard: Guangzhou Huanan Rubber Tyres Co., Ltd, Hangzhou Zhongce Rubber Co., Ltd, Anhui Jiatong Tyres Co., Ltd, Sanjiao Tyres Co., Ltd, Beijing Research & Design Institute of Rubber Industry, Beijing Capital Tyre Co., Ltd, Shandong Linglong Rubber Co., Ltd, Qingdao Huanghai Rubber Group Co., Ltd, Nanjing Kumho Tyre Co., Ltd, Shantou Haoda Tyre Testing Equipment Co., Ltd, and Qingdao Gaoxiao Measurement & Control Technology Co. Ltd. Main drafters of this Standard: Lu Kun, Chi Wen, Chen Guohua, Zu Enzhong, Yi Shanhui, Xu Mianhong, Li Hongwei, Zhao Dongmei, Mai Maohua, Kong Lingfu, Jiang Qing, Chen Xun, and Liu Hong. History versions replaced by this Standard are: Page 5 of 22

6 GB/T , GB/T ; GB/T , GB/T , GB/T ; GB/T , GB/T ; GB/T , GB/T Page 6 of 22

7 Laboratory Test Methods for Passenger Car Tyres Capabilities 1. Scope This Standard specifies laboratory test methods for verifying the capabilities of tyres for passenger cars, including terms and definitions used in the tests, testing equipment and precision, test conditions, testing procedures, judgment criteria, and test reports. Of the test methods presented, it is possible that only some will be required, depending on the type of tyre to be tested (tube or tubeless, diagonal or radial). This Standard includes: (1) Bead unseating test: assesses the resistance of the tubeless tire to bead unseating. (2) Strength test: assesses the capability of the tyre structure, with respect to braking energy, in the tread area. (3) High speed test: assesses the capability of the tyre according to its speed category. (4) Endurance test: assesses the resistance of the type, with respect to service at specified load and speed. (5) Low-pressure performance test: assesses reliability of radial tyres under low pressure, with respect to service at specified load, speed, and low pressure conditions. The test methods presented in this Standard are not intended for gradation of tyre performance or quality levels. This Standard applies to all pneumatic-tyres for passenger cars. 2. Normative references The following documents contain provisions which, through reference in this Standard, constitute provisions of this Standard. For all dated references, none of their later amendments (not including corrected parts) or revisions applies to this Standard. However, all parties to the agreement based on this Standard are encouraged to investigate the possibility of applying the most recent editions of these documents. For undated references, the latest edition of the referenced document applies to this Standard. GB/T Size designation dimensions inflation pressure and load capacity for passenger car tyres GB/T 6326 Tyre terms and definitions (GB/T , ISO 4223-l: 2002, Definitions of some terms used in tyre industry - Part l: Pneumatic tyros, NEQ) GB 9743 Passenger car tyres Page 7 of 22

8 5.5 Low-pressure performance test Test conditions and preparation This test applies to radial tyres only (not include T Type temporary-use spare tyres) and shall be carried out immediately after the endurance test stated in 5.4. The same tyre and rim assembly used in the endurance test stated in 5.4 shall be used and be adjusted to the specified test pressure; for the standard radial tyres of passenger cars, the test pressure is 140kPa; for the reinforced radial tyres of passenger cars, the test pressure is 160kPa; The tyre and rim assembly with readjusted pressure shall be rested at an ambient temperature of 38 C±3 C for at least 2h The test load, speed, and duration shall be set up in accordance with the following requirements: the test load, in kg, shall be 80% of the load-bearing capacity corresponding to the load index of the test tyre; Test speed 120km/h; Test duration 90min The test drum shall be accelerated at a constant rate to the speed specified in within 5 min During the test, the temperature in the test room shall be maintained at 38 C±3 C Test procedure Readjust the pressure of the rested test tyre to the value specified in Mount the tyre and rim assembly prepared according to onto the high speed endurance testing machine. Position it perpendicular to the outer surface of the test drum, and apply a load specified in to the surface Carry the test through with the conditions given in without interruptions. Throughout the test, the tyre shall not be artificially cooled and the inflation pressure shall not be corrected, and the test speed and load shall be kept constant After the test is completed with the specified procedure, allow the test tyre to cool naturally for (15~25) min. Measure the pressure of the tyre within this time period. After the tyre completely cools down, remove it and check its appearance. 6. Requirements 6.1 Test samples Three tyres with identical characteristics shall comprise a test sample respectively used for the bead unseating test, strength test, high speed test, endurance test, and low-pressure performance test. Page 15 of 22

9 If the tyre meets the following requirements after being tested in accordance with 5.5, it shall be judged as passed ; otherwise it shall be judged as failed : The tyre pressure measured in accordance with is not lower than 95% of the initial pressure specified in No visual evidence of separation (tread, side walls, cord, belt, breaker, bead, interliner), chunking, open slices, cracking, cord cracking, cord cracking, or broken cord is found in appearance check. 7. Test report The test report should include the following contents: a) Name of the test tyre manufacturer, trademark, specifications, and production number; b) Load index or ply rating, maximum load-bearing capacity, speed symbol, and material structure of the test tyres; c) Specifications of test rim; d) Ambient temperature in the laboratory; e) Standard code of test method and test date; f) Test pressure and test load; g) Test duration and test speed of each test period; h) Type of bead unseating block and horizontal distance p; i) Bead unseating resistances at all test points of the bead unseating test; j) Status at all test points of the bead unseating test: not unseated or unseated ; k) Diameter of plunger used in strength test; l) Applied force, travel, and breaking energy at all test points of strength test; m) Status at all test points of the strength test: not penetrated, penetrated, or reached rim but not penetrated ; n) The appearance and retained pressure of tyre after high speed, endurance, or low-pressure test; o) Records or description of other unexpected situations during the tests; p) Conclusion: passed or failed. Page 17 of 22

10 , , Chapter or clause number of this Standard Chapter or clause number of ISO 10191: Table 6 Table Table A.1 (Continued) Chapter or clause number of this Standard Chapter or clause number of ISO 10191: Table 7 Table 6 and Table Table 8 Table Annex A Page 19 of 22

11 Annex B (Informative) Technical differences between this Standard and ISO 10191:1995 and causes for these differences Table B.1 is a list of technical differences between this Standard and ISO 10191: 1995 (2nd English edition) and causes for these differences. Table B.1 List of technical differences between this Standard and ISO 10191:1995 and causes for these differences Chapter or clause number of this Standard Technical difference Causes , , Figure , Table Table 2 Extended the scope of the Standard; added low-pressure test for radial tyres; specified new passenger car tyres Directly referenced GB/T 6326, GB/T 2978, and GB 9743; deleted ISO referenced in ISO Deleted most of the statement of the international standard and retained only 1 key term. The diameter of the test drum is set at 1700m, which is one of the two diameters specified in ISO And a different tolerance is used. Added the radial runout requirement on the test drum surface and the requirement on the installation position of the temperature measuring device. Added Type C standard bead unseating block Added the requirement that the appearance of the test tyre be in accordance with GB This Standard specifies that the measured rim is a test rim specified GB/T 2978, while ISO allows all recommended rims that meet the requirements on measured width Added requirements on the inflation pressures for the bead unseating, strength, and endurance test of diagonal tyres. Added the requirement that the ambient temperature be 18 C~36 C. This Standard requires that the p values of Other tubeless passenger car tyres be divided into 4 categories by normal height-width ratio. The latest FMVSS safety requirements GB/T 6326 is not equivalent to ISO , but it contains a total of 410 terms which cover 52 of the 58 terms in ISO And as the test methods involve test loads, measurement of tyre rims, and other requirements, GB/T 2978 and GB 9743 are referenced. GB/T 6326 already contains most of the statement of ISO In order to simplify the standard, only necessary terms and definitions are retained. The 1700mm±17mm requirement on test drum diameter in the original national standard is retained. The requirement on test precision is stricter than that in ISO Higher requirement is set out on the precision of equipment. Specially used for the bead unseating test of tyres with normal rim diameters of 20 ~28 Tyres that do not meet appearance requirements are unsuitable for the test. A test rim that matches the required dimensions for measured rims is used to maintain the precision of the test method and the Standard and facilitate the comparison of test results. To meet product categorization requirements in GB/T To retain the requirement in the original national standard. The p values specified in ISO do not apply to ultra-flat tyres with normal height-width ratios of 50 and below. Page 20 of 22

12 6.6 7 and the inflating valve should be free of gas leaks. After the tyre is tested and cooled, the measured pressure of the test tyre shall not be lower than 95% of the initial pressure. Added the judgment criteria for the low-pressure performance test of radial tyres. Added requirements on the test report and its contents. Deleted the informative Annex A of ISO suitable for the test. Latest requirements of FMVSS 139 are adopted in order to meet the safety requirements of tyres. The latest requirements of FMVSS 139 are adopted. To match the industrial conventions of China and facilitate the uniformity of standard. Tyres without labels do not meet requirements in GB 9743 and are unsuitable for the test. END Page 22 of 22