Main technical indicators and parameters

0 Sample fixing device

According to the size of the wire diameter, the friction steel needle can be adjusted up and down to effectively contact the sample, ensuring that the force applied to the sample during the test is 4.5N, ensuring that the steel needle scrapes along the top of the sample, and keeping the sample straight throughout the entire test process.

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Steel needle

The diameter of the steel needle is 0.625 ± 0.025 for females. The steel needle is installed horizontally and the driving device is scraped perpendicular to the axis of the sample

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Using a stepper machine as the power source, the speed of the stepper motor is controlled by touch screen and PLC programming. The eccentric wheel drives the pull rod to ensure that the stroke of the scraping needle is between 9.5 ± 1.6mm, ensuring that the scraping needle circulates back and forth along the sample axis at a rate of 601 times/min. The counting principle is that the pulse signal from the PLC to the stepper motor is fed back to the touch screen, and the number of times the scraping needle runs back and forth is displayed on the touch screen. The total number of scraping needle runs can be set directly on the touch screen according to the relevant requirements of the sample, and the number of runs can be set to automatically stop and prompt.

In comparison, the control system of the original equipment used a potentiometer to adjust the speed of the micro motor. The speed was unstable, the gear ratio was fixed, and the operating speed of the needle was difficult to adjust. The original counting method used a proximity switch, which could easily lead to no counting or multiple counting when exposed under the spindle, and it was not beautiful. Now changed to stepper motor, touch screen, PLC programming control, with reliable performance, high stability, and easy operation