How to judge the standard of precision of spring testing machine

The primary requirement for small load springs, especially high stiffness precision springs, is the high test accuracy of the equipment. Small changes in displacement will cause large changes in the test force. It is very easy to ensure the test accuracy of the test force. , But to ensure the accuracy of the displacement of another parameter of the spring testing machine is the key to ensuring the accuracy of the spring testing, and it is also the standard for judging the accuracy of the spring testing machine. Therefore, more and more users regard the accuracy of displacement testing as the standard to measure the level of the testing machine. In the national standards for spring testing machines, the requirements for displacement accuracy are very low, which cannot meet the requirements of high-stiffness precision springs. Therefore, for the testing machine manufacturer, it is necessary to improve the displacement test accuracy to meet the requirements of users. There are many factors that affect the accuracy of displacement testing, such as the detection method, the structure of the whole machine, the rigidity of the whole machine, the parallelism of the pressure plate, the measuring element, the material, the load displacement sink, etc. As long as these factors are overcome, the guarantee of the displacement accuracy is impossible. questionable.

The detection of the spring testing machine is to detect the displacement in strict accordance with the standard, which can ensure that the spring is placed in different places of the pressure plate and the test force is basically the same, and that within the full range of the test force, any load will not cause the load cell The displacement sinks. In addition, the influence of the loading method of the spring testing machine on the test results cannot be ignored. The early loading method mainly used ordinary AC motor to drive the transmission system to load. The loading speed cannot be adjusted. For elastic elements such as springs, due to the presence of springback stress, the data collected automatically during rapid compression is different from the data collected by slow compression or static compression. The data varies greatly. Nowadays, variable speed systems such as AC servo speed control systems are used to simulate the working state of the spring realistically, and the internal stress of the spring in this state is actually measured to provide a basis for spring design.

With the development of computer technology, the shortcomings of the simpler functions of the single-chip microcomputer have been improved by the microcomputer. The intelligent function setting expert system, parameter selection, database, clear window Chinese interface, simple mouse operation, make the spring test process The most idealized state in the system becomes possible, and the level of intelligence has been greatly improved. The operator can perform measurement and control according to any pre-set mode with a light click of the mouse, and set different test speeds and test processes. The parameters in the test mode and the entire test process can be controlled according to people’s will. The test curve and test data can be displayed in real time. The test data can also be calculated, sorted and output according to industry standards or corporate standards. It can also be used for previous tests. Process and test results are inquired, and powerful calculation and mathematical statistics replace the complicated work in the past, which greatly reduces the amount of labor.

In addition, the application of computer network technology will combine the detection control machine (referred to as the lower computer) and the main control machine (referred to as the upper computer) of the computing center to realize the transmission, processing and comprehensive management of test data. In the laboratory, the upper computer realizes the comprehensive management of the lower computer group.