It is composed of acceleration sensor, amplifier, data processing, display and recording, and its main performance requirements are as follows
a) The frequency response range is 0+0.2~1000Hz, the/band cut-off point is 3t0.5dB, and the attenuation slope is - 9~- 24dB/oct.
b) Meet the acceleration value detection requirements proposed in 5.2.6.
c) The measurement uncertainty is 5%.
Inspection steps
a) Fix the acceleration sensor rigidly on the head type collision test part, and the included angle between the sensor sensitive axis and the normal of the head type collision point shall not be greater than 5 °.
b) Calibration of collision inspection device: adjust the height of the head form of the collision test bench (the vertical distance between the impact point of the head form and the impact surface of the anvil) to make it collide with the standard test block. The peak acceleration must reach 400g, three consecutive collisions, and the deviation of the peak acceleration of each collision shall not be greater than 3%; The action time deviation of 200g is not more than 0.1 ms. Calibration shall be carried out before and after the inspection. If the peak acceleration and 200g action time after the inspection exceed the above requirements, the inspection results shall be deemed invalid.
c) Wear the helmet treated before inspection on the corresponding head form, fasten the harness, and conduct inspection according to the inspection conditions in Table 7.
d) The inspection results shall be evaluated according to regulations.
Electric vehicle helmet Penetration resistance test of the manufacturer
1 Treatment before helmet inspection
According to the regulations, each helmet shall be treated at any time or inspected at room temperature.
2 Drop type penetration test bench
It is composed of falling platform, steel cone, head type, guide rail and lifting release mechanism, and shall meet the following technical requirements:
a) Falling platform: it is the framework that can realize the lifting, releasing and directional impact of the steel cone along the guide rail, and it shall meet the requirements of 8.3c) for the falling height of the steel cone. Its bottom is fixed on a reinforced concrete foundation with a mass of not less than 1 t.
b) Steel cone: see Figure 6 for the structure and size. The material is tool steel (T10A), with a mass of 30+0.3kg and a hardness not lower than HRC50. L in the figure is the height of the part involved in penetration, which should be greater than 40mm.
c) Head type: it must comply with the provisions of 6.7.2.1a) on head size and be rigidly fixed on the base at the bottom of the falling platform.
