In the long-term working process, the injection molding machine template is subjected to repeated alternating loads, and its fatigue life is directly related to the reliability and stability of the injection molding machine. The following will conduct an in-depth analysis of its fatigue life.
First of all, it is key to understand the characteristics of alternating loads. In the process of opening and closing the mold, the injection molding machine template is subjected to various forms of loads such as periodic pressure, tension and bending moment. The size, frequency and waveform of these loads will vary depending on the injection molding process parameters, mold weight and type of injection molded products. By installing sensors on the template, the load data in actual work is monitored and recorded in real time to provide an accurate load spectrum for subsequent fatigue analysis.
Secondly, the performance of the material has an important influence on the fatigue life. The injection molding machine template is usually made of materials such as high-strength alloy steel, and its internal organizational structure, hardness and toughness will affect the fatigue performance of the material. Metallographic analysis and mechanical property testing of the template material are carried out to determine the basic properties of the material, such as yield strength, tensile strength, elongation, etc. At the same time, the fatigue limit of the material is considered, that is, the maximum stress value without fatigue damage under a certain number of cycles, which is an important basis for evaluating the fatigue life of the template.
Furthermore, the structural design of the template is also a key factor affecting fatigue life. Reasonable structural layout can evenly disperse alternating loads and reduce stress concentration areas. For example, appropriate fillet transition and rib design in the holes, grooves and other parts of the template can effectively reduce local stress peaks and improve overall fatigue strength. Finite element analysis software is used to simulate and calculate the stress distribution of the template under alternating loads, find high stress areas, and optimize the structure in a targeted manner.
From the perspective of processing technology, the processing accuracy and surface quality of the template cannot be ignored. High-precision processing can ensure the accuracy of the dimensions of each part of the template and avoid local stress concentration caused by processing errors. Good surface quality, such as low roughness and no processing defects, can reduce the generation of surface microcracks and improve the fatigue resistance of the material. Advanced processing technology, such as CNC processing, grinding and polishing, is used to ensure that the processing quality of the template meets the requirements.
In addition, working environment factors will also affect the fatigue life of the template. Conditions such as temperature, humidity and corrosive media in the injection molding workshop may accelerate corrosion and fatigue damage of the template material. Taking appropriate protective measures, such as surface coating, anti-corrosion treatment and environmental control, can mitigate the impact of these adverse factors on the fatigue life of the template.
In terms of fatigue life assessment methods, the method based on the stress-life (S-N) curve or the strain-life (ε-N) curve is usually used. By conducting fatigue tests on the template material, the corresponding curve data is obtained, and then combined with the load spectrum in actual work, the Miner linear cumulative damage theory and other methods are used to calculate the fatigue damage degree and remaining fatigue life of the template under long-term alternating loads.
The fatigue life analysis of the injection molding machine template under long-term alternating loads needs to comprehensively consider multiple aspects such as load characteristics, material properties, structural design, processing technology, working environment and evaluation methods. By in-depth research and optimization of these factors, the fatigue life of the injection molding machine template can be effectively improved to ensure the normal operation and production efficiency of the injection molding machine.
