The production of spring testing machines in my country has a history of fifty years. This article discusses the development status of domestic spring testing machines based on our products. Most of the spring testing machines produced in the early days are ahead of mechanical transmission and simulation measurement, and the improvement of accuracy is limited. In recent years, with the development of science and technology, we have been absorbing advanced technology at home and abroad and cooperating with many universities. We have established a low, medium and high-end echelon. The test characteristic test is advanced. Has developed static tension and compression, static torsion, high frequency tension and compression fatigue, low
Six different testing methods such as frequency tension and compression fatigue, torsion fatigue, and online testing: mechanical, electronic, electromagnetic, electro-hydraulic, electrical, electro-hydraulic servo, etc. six different loading methods; range from 1N- There are more than 170 kinds of products with different specifications of 500KN.
1. Classification of spring testing machine
Spring testing machines are classified as follows according to the characteristics that can be tested:
Vertical clamping: singular display, double digital display, automatic microcomputer control, torsion, horizontal clamping: double digital display, single digital display, automatic microcomputer control, tension and compression dial, single digital display, double digital display, full Automatic microcomputer-controlled static characteristic test sorting load sorting height sorting compound sorting high frequency fatigue tension and compression fatigue low frequency fatigue mechanical electro-hydraulic servo torsional fatigue
2. The use and development trend of spring tension and compression testing machines with small and medium loads 2.1 Current status of spring tension and compression testing machines This type of testing equipment was mostly manual loading, analog or single-digit display a few years ago, and in the past ten years, double-digit display The testing equipment has become the mainstream equipment, this is because: 1), the dual-digital display testing machine adopts high-precision load sensors, displacement sensors, high-precision amplifiers and other measuring vitality parts due to the test force and displacement, which has high resolution and overcomes The reading error of the human eye is eliminated, and the measurement accuracy is high. 2), the use of computer technology can make the measurement of the two parameters of test force and displacement. The test parameters can be set in advance to improve the degree of automation and data accuracy; the test parameters can also be saved for the next test without repeating input; It can calculate some data and print test data. For example: in the test process, TLS-S10001 can respectively set the compression (or extension) spring compression (tension) to high (length) or compression (tension) deformation, automatically collect the corresponding test force, and store it in the microcontroller , After calculating the segment stiffness, free height, initial tension, and judging whether the spring is qualified, the test data is automatically printed out, and the stored test data can also be inquired.
2.2 The development trend of spring testing machine
The primary requirement of small load springs, especially high-stiffness precision springs, is the high test accuracy of the equipment, because small changes in displacement will cause large changes in the test force, and it is 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 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, the displacement testing accuracy must be improved 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 displacement sink of the load cell, etc. As long as these factors are overcome, the guarantee of the displacement accuracy is Not a problem. Our company’s spring testing machine detects displacement in strict accordance with Japanese standards, 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 any load will not cause load within the full range of the test force. The displacement of the sensor sinks.
In addition, the influence of the loading method of the spring testing machine on the test results cannot be ignored. The early loading methods were mainly driven by ordinary AC motors to load the transmission system. 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 during 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, and simple mouse operation make the spring test the best The ideal state becomes possible, and the level of intelligence has been greatly improved. The operator can measure and control according to any pre-set mode with a light click of the mouse, and set different test speeds and parameters in the test process. , So that 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. Query results, powerful calculation and mathematical statistics functions have replaced the complicated work in the past, greatly reducing 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 central laboratory, The upper computer realizes the comprehensive management of the lower computer group.
As people continue to study spring testing methods, their understanding will continue to deepen. Spring testing opportunities will develop towards highly intelligent people. Testing opportunities that simulate the working parameters, conditions and environment of springs will continue to appear, such as salt spray testing machines, high and low temperature tests. Machine waiting.
Third, the current situation and development trend of heavy load spring compression testing machine
3.1 The status quo of heavy load spring compression testing machine
This type of testing machine is generally used for spring testing in heavy machinery and railway industries. The factory has produced large-scale spring pressure testing machines for more than 30 years. In the development process of more than 30 years, the testing machines have also undergone simple manual control, pendulum force measurement, single-chip control, and electronic measurement. The process of fully automatic measurement is controlled by the computer.
Most of the loading methods are hydraulic. Below 200KN, the motor speed control system is generally used to drive the mechanical transmission system to load. The first TYE-100, TYE-300, and TYE-500 produced by the factory are hydraulic loading, pendulum force measurement, semi-open structure, and are mainly used for the measurement of automobile round springs, leaf springs and railway springs. In recent years, the speed of passenger cars in the railway system has been increased and the spring standards have been revised. The measurement accuracy, measurement methods and lack of data processing functions of the original testing machine have no longer adapted to the requirements of the new standard. The two different grades of electronic and microcomputer-controlled products launched by the factory meet this requirement and have been widely promoted. After user verification, the effect is satisfactory and the response is good.
3.2 Development trend of heavy load spring compression testing machine
Like the small spring testing machine, with the improvement of testing technology and the application of computer technology, both testing technology and control technology require a big improvement. From the perspective of testing technology, the high resolution and stability of load and displacement are the development trend, and the wide load test range is also the development trend. From the perspective of control technology, electronic, microcomputer control, and electro-hydraulic servo microcomputer control will go hand in hand to suit different consumers. But in any case, the test accuracy of the test machine will become higher and higher, and the individualization of the product will become more and more obvious.