Safety helmet impact resistance and puncture testing machine
1、 The purpose of the impact puncture testing machine for safety helmets is:
This instrument is specifically designed to test the impact absorption and puncture resistance of safety helmets. The device detects the impact absorption performance of the safety helmet in the form of natural fall; Detect puncture resistance performance in the form of a peak sound when the circuit is closed and the line is connected. Applicable standards: GB/T 2812-2006 "Test Methods for Safety Hats" Requirements for Impact Absorption and Puncture Resistance Testing Standards, GB/T 2811-2007 "Safety Hats", GB/T2829 "Sampling Procedures and Tables for Periodic Inspection Counting (Suitable for Checking Production Process Stability)", Gb2428 "Adult Head and Face Dimensions"

2、 Main technical indicators of the impact resistance testing machine for safety helmets
1. Head mold: fully complies with the provisions of Appendix A of GB/T 2812-2006 "Test Methods for Safety Hats" standard.
2. Bench: capable of controlling the suspension and release of impact hammers and puncture hammers.
3. Drop hammer: Impact drop hammer: The mass is 5-5.01kg, the hammer head is hemispherical, with a diameter of 96mm, and the material is 45 # steel.
Puncture hammer: The mass is 3-3.05kg, the cone angle of the puncture part is 60 °, the cone tip diameter is 1mm, the length is 40mm, the maximum diameter is 28mm, and the hardness is HRC45. The impact force after the installation of the two hammers fully meets the standard.
4. Force sensor: measuring range 0-20KN, corresponding minimum frequency of 5kHz, dynamic force sensor, accurate to 1N.
5. Base: It has impact resistance and can firmly install force sensors.
6. Power on display device: When the circuit forms a closed loop, it can emit a signal indicating that the puncture cone has contacted the head mold.
7. Hammer height: 1000mm.
8. 1 # and 2 # aluminum silicon alloy test head molds each. Complies with the provisions of Appendix A of GB/T 2812-2006.
9. Working power supply: AC220V, 50Hz

3、 Characteristics of safety helmet puncture resistance testing machine
1. The replacement method of falling hammer and impact hammer is easy to operate.
2. High precision impact force sensor with a minimum frequency of 5kHz, dynamic force sensor with a range of 2t and an accuracy of ± 2.0%.
3. LED digital display, automatically saves maximum force value.

4、 Test method for impact resistance and puncture resistance of safety helmets
Pre treatment: Temperature adjustment treatment: Place the safety helmet separately at 50 ℃± 2 degrees Celsius. -Place in a temperature control box at 10 ℃± 2 ℃ or -20 ℃± 2 ℃ for 3 hours.
UV irradiation pretreatment: Using the priority A method mentioned in the standard, the safety helmet is placed in the UV irradiation box and irradiated for 400 hours ± 4 hours. After removal, it is placed in the laboratory environment for 4 hours.
Immersion treatment: Place the safety helmet in a fresh water tank with a temperature of 20 ℃± 2 ℃ and soak it completely for 3 hours.
The above pre-treatment requirements can be matched (including UV aging, high temperature box, low temperature box, constant temperature water immersion box, temperature and humidity control box)

Test method for impact absorption performance: choose a suitable head mold for the height of the safety helmet worn; Adjust the helmet to the normal use state according to the instructions of the helmet, wear the helmet on the head mold normally, ensure that the contact between the helmet hoop and the head mold is natural and stable, adjust the axis of the drop hammer to coincide with the axis of the sensor, and adjust the height of the drop hammer to 1000mm ± 5mm; if a guided drop hammer system is used, verify that the difference between the end fall speed of 60mm height and the end free fall speed is not more than 0.5% before the test; Test the safety helmets that have been pre treated with immersion, high temperature, low temperature, and ultraviolet radiation in sequence. Record the impact value accurately to 1N.

Test method for puncture resistance: choose a suitable head mold for the height of the safety helmet worn; Adjust the safety helmet to its normal usage state according to the instructions, wear the helmet normally on the head mold, ensure that the contact between the helmet hoop and the head mold is natural and stable, adjust the axis of the puncture cone to pass through the weakest point of the structure within a diameter range of 100mm from the center of the safety helmet top, adjust the height of the puncture cone tip to the contact point of the helmet top to 1000mm ± 5mm. If using a guided drop hammer system, it should be verified before testing that the difference between the 60mm height drop velocity and the free fall velocity does not exceed 0.5%; Test the safety helmets that have been pre treated with immersion, high temperature, low temperature, and ultraviolet radiation in sequence, observe the damage of the powered display device and the safety helmet, and record the puncture results.