| With the rapid development of the auto industry, engine connecting-rod fracture splitting technology will replace the traditional processing means. Connecting-rod fracture splitting technology is the newest processing connecting-rod internationally. There are few manufacturing procedures to reduce the equipment investment;there are few material wastage to be used sufficiently; the products have high quality to promote load-bearing capacity. However, there are no products of the same type. It is impractical for the small-size connecting-rod production enterprises to spend a large amount of money on imported equipment to improve the traditional production line. Its key technologies include processing fracture splitting groove, directional fracture splitting, certain torque, assembly and screw bolt. The aim of processing fracture splitting groove is to produce notch effect and promote stress concentration factor to make meet the requirement of opening model and to ascertain the fracture splitting takes place in the location and reduce separation force and connecting rod big end hole deformation. Therefore, reasonable designing and processing fracture splitting groove of connecting-rod is the precondition for the connecting-rod fracture splitting processing technology. Processing fracture splitting groove of connecting-rod, as the key process of fracture splitting technology, its processing method and processing quality play an important role in quality of connecting-rod fracture splitting.The research program applies for the National"863"plan"engine connecting-rod fracture techniques and equipment". Regulations on the National Natural Science Funds project"cracking dynamic behavior and fracture splitting processing technology of section parts"and science and technology developing project of Jilin province"Research and manufacture automation equipment of laser processing fracture splitting groove"and etc to do the research on connecting-rod fracture splitting core technologies and to develop the equipment of connecting-rod fracture splitting core component with independent intellectual property. The research derives from the above program.Through theoretical analysis and experimental study, this thesis do the further discussion on laser processing fracture splitting groove. On this basis, the first automation equipment of laser processing fracture splitting groove equipment is designed and is assembled with equipment of connecting-rod fracture splitting and certain torque assembly screw bolt into semi-automation production of connecting-rod fracture splitting. This is very important for development of connecting-rod fracture splitting technology and promotion of engine industry technical innovation.The main content and conclusion of the research is as follows:1. The relationship between fracture stress and length of crack is analyzed by applying fracture mechanics. By using the ABAQUS software to do the do the numerical simulation orthogonal experiment on fracture splitting groove geometric parameters, analyzing the influence on separation force of the depth of groove h ,flare angleαand curvature radius . The experimental results show that influence of depth of groove on separation forceis the most prominent. Process fracture splitting groove with the 52D test sample in way of with the means of mechanical broaching, wire-electrode cutting and laser beam cutting. Do the tensile test on test sample and analyze the fracture force, fracture surface and microscopic figure. The experiment shows that for the fracture splitting groove processed by mechanical broaching wire-electrode cutting, plastic deformation will take place during fracture. For rh those through laser processing fracture splitting groove, quasi-cleavage fracture. Observe the fracture surface and microscopic figure, there are the characters good for fracture splitting such as quenching, embrittlement, micro-crack, acicular and crystal in the laser processing fracture splitting groove root. Through the experiment, the advantage of the laser processing fracture splitting groove is assured.2. By applying the interaction theory of metal materials, this thesis discusses fundamental mode , gaussian distribution laser beam light sources cutting temperature distribution; do the reasonable hypothesis during laser processing fracture splitting groove. Do the temperature field simulation on course of laser processing fracture splitting groove by applying the ANSYS software to make the gasification process and materials melting in the process of laser processing by using birth-death element show directly in temperature field distribution nephogram. The depth and width of the fracture splitting groove can be measured. Analyze the fracture splitting groove shape of focused radius, cutting velocity, peak power and pulse time from pulse laser drilling and continuity in work-piece surface. Compare the result of the numerical simulation and testify the effectiveness of the numerical simulation and accuracy. TEM003. Analyze the influence of peak power, pulse time, pulse frequency, cutting velocity, assisting gas type, assisting gas pressure, workpiece surface roughness, laser incident angle, cutting mode, focus distance on course of laser processing fracture splitting groove. Through two orthogonal experiments, judge the primary-secondary on processing fracture splitting groove. Draw the effect figures of influencing factors by applying the minitab software to show the influence of each factor on the depth and width of the groove. Optimize the laser processing parameters of types of 52D和M0406 through interaction effect table between peak power and pulse time through orthogonal experiment. Through practical application, the parameters after optimization can meet the requirement of the connecting-rod fracture splitting technology. Choose rationally the peak power, pulse time, pulse frequency, cutting velocity can not only meet the requirement of technology and promote the working efficiency.4. By applying the high power Nd:YAG laser to process the connecting-rod splitting fracture groove and research and design equipment of laser processing fracture splitting groove for connecting-rod with integration of optical mechanical and electrical. The choice of laser system and the design of mechanical system and electric control system sufficiently consider the scope of application to make the equipment of laser processing fracture splitting groove for connecting-rod process the fracture splitting groove for multi-variety and multi-type of connecting-rods; since there are precise optical elements in cutting head of laser, in designing it, in order to avoid the scratch and collide with the working piece and working plat, time-delay and wait),Z axis limit location and proximity switch and numerical control soft limit location are applied to ensure the security and stability. Through trial production with multi-variety and multi-type of connecting-rod, this equipment can meet the demand of the technology. The products are affirmed by the factory.5. In the practical application of the equipment, fracture splitting defects such as drop clinker and slag inclusion can be reduced and the laser cutting parameters and hardness of lower limit can be improved. The design scheme for the laser processing fracture splitting groove technology and automation equipment in processing connecting-rod fracture splitting groove in small quantity can be improved. It is more convenient to adjust the deflection angle of laser processing fracture splitting groove equipment to promote the precision of the laser cutting. It is simpler to change the clamping apparatus of different kinds and remove the equipment of hydraulic system..
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