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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard was proposed by China Petroleum and Chemical Industry Federation.
This standard is under the jurisdiction of National Technical Committee 19 on Tyres and Rims of Standardization Administration of China (SAC/TC 19).
Endurance test method for agricultural tyres
1 Scope
This standard specifies the endurance test method for agricultural tyres, including terms and definitions of tyres, test apparatus and precision, test conditions, test procedures, judgment rules and test reports.
This standard is applicable to agricultural radial tyres.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 1192 Technical specification of agricultural tyres
GB/T 2979 Size designation, dimensions, inflation pressure and load capacity for agricultural tyres
GB/T 6326 Tyre terms and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 6326 apply.
4 Test apparatus and precision
4.1 The maximum measuring range of the pressure gauge shall be at least 1,000 kPa, with a precision of ± 10 kPa.
4.2 The tester drum shall be 1,700 mm in diameter, with a diameter tolerance of ± 1%.
4.3 The test drum surface of the tester shall be a smooth steel surface, with its width greater than or equal to the total section width of the test tyre.
4.4 The loading capacity of the test loading device shall meet the requirements of the test method, with a precision of ± 1.5% of the full measuring range.
4.5 The speed of the tester drum and test device shall meet the requirements of the test method, with a speed precision of km/h.
4.6 The radial run-out of the test drum shall be ≤ 0.25mm.
5 Test conditions
5.1 The appearance quality of test tyres shall meet the requirements of GB/T 1192.
5.2 Install the test tyre on the measuring rim specified in GB/T 2979, and inflate the tyre with the standard pressure specified in GB/T 2979. The maximum sidewall inflation pressure must not be exceeded during installation. When the tyre is mounted on the rim, inflate the tyre to the appropriate test pressure.
5.3 When testing tubed tyre, a new inner tube shall be used (e.g. a tyre that is not marked as "tubeless").
5.4 The assembly of test tyre and rim shall be placed at an ambient temperature of 38 ℃ ± 3 ℃ for at least 3 h.
5.5 Other test conditions shall meet those specified in Table 1.
Table 1 Endurance test conditions for agricultural tyres
Test phase Test time/h Test load/% Test speed/(km/h) Pressure/kPa
1 7 66 20 Standard pressure
2 16 84 20
3 24 101 20
If the test drum's diameter exceeds 1,700 mm, the above test load percentages shall be calculated using the following formula:
(rounded off to two decimal places)
where,
R1——the diameter of the test drum, mm;
R2——the standard test drum diameter, 1,700mm;
rT——the outer diameter of the tyre, mm;
F1——the load percentage of the test drum;
F2——the load percentage applied to the Φ1,700mm standard drum according to the above table.
5.6 The ambient temperature during the test shall be maintained within the range of 38 ℃ ± 3 ℃. The ambient temperature measuring device should be set within the range of 150 mm to 1,000 mm from the test tyre.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Test apparatus and precision
5 Test conditions
6 Test procedures
7 Judgment rules
8 Test report
