GB/T 37259-2018Test method for aging automobile tyres (English PDF)

1 Scope

This Standard specifies test devices, reagents and materials, sampling and samples, pre-aging tyre fitting and adjustment, tyre aging, post-aging tyre storage, post-aging tyre testing, and test report for tyre aging test.

This Standard applies to new passenger car tyres and truck and bus tyres.

2 Normative references

The following documents are indispensable for the application of this document.

For the dated references, only the editions with the dates indicated are applicable to this document. For the undated references, the latest edition (including all the amendments) are applicable to this document.

GB/T 4501 Laboratory test methods for truck and bus tyres capabilities

GB/T 4502 Laboratory test methods for passenger car tyres capabilities

GB/T 6326 Tyre terms and definitions

3 Terms and definitions

The terms and definitions defined in GB/T 6326 apply to this document.

4 Instrument accuracy

4.1 The tyre pressure gauge has an accuracy of ±5 kPa.

4.2 The oxygen content measuring instrument has a measurement accuracy of ±1%.

5 Test devices

5.1 The aging oven is constructed so that the tyres are placed in a controllable temperature environment and the monitoring of other environmental conditions can be regulated, such as humidity.

5.2 The aging oven shall be constructed so that the tyres are not placed in […]

9 Tyre aging

9.2.4 If the measured thermal inflation pressure deviates within ±1% from the target inflation pressure, no gas filling adjustment is required; otherwise, the oxygen/nitrogen mixture is added and adjusted to the target thermal inflation pressure (±1%). The oxygen/nitrogen mixture volume ratio shall meet 50%O2/50%N2, ±2%.

9.2.5 It shall not be over-inflated. When exceeding the target thermal inflation pressure, excess gas is released, to ensure oxygen/nitrogen balance in the tyre cavity.

9.2.6 PUT the tyres back into the balanced aging oven.

9.2.7 After the test for 7 d and inspection, the above operation is repeated once every 14 d. At a laboratory ambient temperature of 23 °C±5 °C, the measurement is continued, until the end of the test.

9.2.8 Before the air pressure is checked, the time the tyre is placed outside the aging oven shall not exceed 145 min; otherwise the overall time for placing in the aging oven shall be extended.

10 Post-aging tyre storage

10.1 At the end of the 35 d aging (including extra time adjustment), the tyre is removed and cooled for 3 h.

10.2 MEASURE and RECORD the final inflation pressure.

10.3 CHECK and RECORD whether the appearance has anomalies. Unplug the valve core; and deflate the tyre.

10.4 FILL the tyres with air as follows.

a) At a laboratory ambient temperature of 23 °C±5 °C, according to the provisions of Table 1, cold-inflate the tyre;

b) Deflate to atmospheric pressure;

c) Inflate to a prescribed cold inflation pressure;

d) Deflate to atmospheric pressure;

e) Inflate to the storage air pressure specified in Table 2. […]