GB/T 38796-2020Performance requirements and test methods of automobile blow-out emergency safety device (English PDF)

4.2.4 Other requirements

During the test, the automobile blow-out emergency safety device shall not have failure phenomenon such as obvious deformation, falling off, cracking and fracture.

5.1 Test conditions

5.1.1 Test equipment

The installation of measuring instruments must not affect the driving safety of the vehicle. The measuring instruments and accuracy are as follows:

a) Speedometer: 1%;

b) Braking distance tester: 1%;

c) Time measuring instrument: 1%;

d) Steering wheel dynamometer: 1%.

5.1.2 Test vehicle and mass status

5.1.2.1 The technical status of the test vehicle that is equipped with an automobile blow-out emergency safety device shall meet the requirements of GB/T 12534.

5.1.2.2 The test vehicle shall be set at the maximum manufacturer's total mass status; the load shall be evenly distributed; the axle load distribution shall comply with the factory regulations. The tractor shall be tested in the train condition.

5.1.3 Test site and environment

The requirements for test site and environment are as follows:

a) The test road shall be a dry, hard, smooth and clean cement or asphalt road; the slope of the test road in any direction shall not exceed 2%;

b) The wind speed is not more than 5 m/s;

c) The temperature does not exceed 40 °C.

5.1.4 Tire blow-out simulation requirements

restricted after a blow-out and cannot reach the specified speed, the corresponding test after the blow-out shall be performed at the maximum speed that the vehicle can reach.

5.2.3 Corner driving blow-out test

5.2.3.1 The test vehicle travels at a constant speed of 50 km/h ± 2 km/h along a curve with a radius of 150 m; the tire on the outer side of the simulated steering shaft blows out; after the tire blow-out, the driver immediately conducts the type-0 test of engine engagement; during the whole process, use the steering wheel dynamometer to measure the maximum steering force that is applied by the driver to the outer edge of the steering wheel during the process of maintaining a curve driving before and after the tire blow-out; calculate the maximum steering force increment before and after the tire blow-out; at the same time, record the test vehicle speed and braking distance; confirm whether the test vehicle exceeds the test track.

Note: Early braking during the test may affect the overall test effect, so, the driver should avoid such situations.

5.2.3.2 For dual-steering shaft vehicles, it is available to simulate a single-sided tire blow-out only on the primary shaft.

5.2.3.3 For vehicles which are equipped with electronic control systems such as ESC or non-mechanical automobile blow-out emergency safety device, if the vehicle speed is automatically restricted after a blow-out and cannot reach the specified speed, the corresponding test after the blow-out shall be performed at the maximum speed that the vehicle can reach.

5.2.4 Steering ability test after a blow-out

Before the blow-out test and after the blow-out test according to either method of 5.2.2 or 5.2.3, respectively drive the test vehicle around the pile at a speed of 50 km/h ± 2 km/h; arrange the stakes in accordance with Figure 1; measure the steering force that is applied to the outer edge of the steering wheel during the driving process; calculate the average value of the two steering force peaks when the steering wheel turns left and right before and after the tire burst-out in the effective stake area; respectively calculate the increment of average value of the front and rear steering wheels when the steering wheel turns left and right before and after the tire blow-out; the vehicle shall not knock down the stake during the test.

For vehicles which are equipped with electronic control systems such as ESC or non-mechanical automobile blow-out emergency safety device, if the vehicle speed is automatically restricted after a blow-out and cannot reach the specified […]