Important Factors of Performance and Accuracy of Tensile Testing Machine

1. The first is the force sensor of the tension machine, because the quality of the sensor determines the accuracy of the testing machine and the stability of the force measurement. Currently on the market, the small force of the sensor used in the machine generally uses the S-type sensor, and the value is generally used. Radial sensors, the internal sensor is generally resistive strain gauge type, if the strain gauge is not high accuracy or fixed strain gauge with anti-aging ability is not good or sensor material is not good will affect the accuracy and service life of the sensor. The imported sensors adopted by the company are the world's most famous sensor manufacturers, American Force Sensors. The sensors have high accuracy, good linearity, and very stable performance. They will not change for decades.

2. The second is the component ball screw that drives the sensor movement. If there is a gap in the screw, the future test data will directly respond to the maximum deformation and elongation after the test. At present, on the market, some of the lead screws are made of T-shaped ordinary lead screws. In this case, the first gap is relatively large, and the second one is that the friction force is relatively short and the service life is short. The lead screw used is a high-precision ball without clearance from Germany. Screw, surface hardening hardness of HRC58-62, service life of up to several decades. And to ensure the same accuracy.

3. Once again, the drive system of the Rally machine. At present, the Rally machine drive system on the market is equipped with a speed reducer, and some use an ordinary belt. The main disadvantages of these two types of transmission methods are: the former needs periodic lubrication, and the latter is The synchronization of the drive cannot be guaranteed to affect the test results. The company's tension machine drive system uses full arc synchronous belt deceleration to ensure the synchronization accuracy of transmission, high transmission accuracy, high efficiency, smooth transmission, low noise, no maintenance and long service life.

4. Once again, the power source (motor) of the pulling machine is also called a motor. At present, some of the pulling machines in the market use ordinary three-phase motors or variable-frequency motors. This type of motor uses analog signal control, slow control response, inaccurate positioning, and general adjustment. Narrow speed range, high speed, no speed, no speed, low speed, no speed, and inaccurate speed control. The motor used by the company's Rally machine is Panasonic's all-digital AC servo motor. The control mode adopts all-digital pulse control, and the speed range is wide. , up to 0.001-1000MM/MIN, accurate control positioning, fast response, 0.01 seconds can be added to full speed, the motor can ensure full-scale speed control accuracy, and long life, up to several decades, and no maintenance.

5. The last is the measurement and control system (ie, software and hardware) of the Rally machine. Currently, most of the R&D systems of the Rally machine are controlled by an 8-bit single-chip microcomputer. The sampling rate is low, and the anti-interference ability is poor. The other is the AD conversion. If the number of digits of the AD converter is the resolution is low. Then the measurement will not be accurate. The company's measurement and control system uses Hytest V6.0, the controller developed by the world's most advanced 32-bit ARM technology. This controller is based on the 32-bit ARM platform and runs the company's time-and-multitasking operating system, which makes the program run more smoothly. The system is more stable. Sampling rate up to 200 times per second, plus 24-bit high-precision low-noise high-speed AD converter, so that the entire measurement and control system more high-precision, high-stability control of the entire test process, the upper computer software for the company lasted 5 The three-digit full-loop control software developed in 2011 has two control methods: 1. PID control adjustment method 2. Modular lake control adjustment method (the first in the industry). The entire test process can achieve constant force value control, constant displacement control, constant deformation control, low frequency fatigue control and program arbitrary control.