Research On Surface Strengthening Technology Application Of Core Component Of The Splitting Connecting Rod Machine

The connecting rod is important part in automobile engine, bears alternation loading such as compression, drawing, bending produced by explosive power and the inertial force moving back and forth that fuel burns mainly. This is as far as possible small with regard to the mass demanding a connecting rod, has sufficient intensities composing in reply with stiffness, higher fabrication assembling accuracy to satisfy service conditions. On the manufacturing process, the connecting rods are more difficult to forging and machining of auto parts. Its manufacturing methods and techniques, at home and abroad have given great attention. The splitting processing technology of connecting rod becomes the up-to-date technology that the connecting rod processes at home and abroad. The technology of connecting rod splitting decomposition needs three key working procedures: splitting decomposition groove machining, controlled splitting decomposition and bolt assembling. Controlled splitting decomposition of connecting rod is the key pivotal working procedures of the splitting technology, the way of manufacturing influence the power of splitting decomposition. Splitting equipment creates the key assembling engineering level height that whether the working procedure deciding splitting decomposition can proceed as planned and without a hitch to be.Once splitting decomposition various malfunction appears on equipment, defect to varying degrees will appear over the splitting connecting rod. Machine tool having machinery system, hydraulic pressure system, electrical and Computer Control System, lubricating systematic, pneμmatic puffing residue system mainly and so on is composed of splitting decomposition. Among them, mechanical systems in the bulge-off fixture, the core of the entire machine tool components, throughout the cleavage process in the brittle fracture of the connecting rod bearing and transmission from the role of impact loading, are extremely fragile parts. A well-designed fixture of fracture splitting machine is the smooth implementation of fracture splitting process a crucial element.This paper mainly fracture splitting machine taper-lock bar, moving sets, fix cover, will cover the wear failure, the reasons for early failure analysis and research, application and reasonable appropriate surface hardening technology applied to solve the wear failure and early failure. Main course of the study are as follows:1) Comparing the different fracture splitting device core components used expansion off fixture structure and action, analyzes the equipment, fixture layout problems arising from a variety of reasons and compared with foreign similar equipment shortcomings need to be improved by the method used and technology.2) Analyzing failure types and causes of pull rod and swelling produced adhesive wear, abrasive wear, and fatigue wear failure, from the view of tribology. Analyzing taper-lock produced limitation in advance causes from perspective of design structure, processing technology, design assembly, metal science and heat treatment. Cold die steel materials used to replace the original fixture materials to meet the unreasonable use. By changing breaking apart designing that clamp part structure prevents equipment from appearing in debugging and scene application, problem appears once again。By changing the structure of the core-driven layout and the hardness of working surface, resolving the surface problem of taper-lock bar. Adopt the surface super elevation hardness technology to get rid of the problem that the cover material resolving a pull rod and swelling wears away gravely. A reasonable Cr12MoV, 7CrSiMnMoV materials, forging and quenching process, to prevent the pull rod and swelling in the course of thermal processing technology appear unreasonable phenomena resulting from the failure.3) Analysis of the application of TD processing feasibility and results of application. With typical application examples, analysis swelling material Cr12MoV , the pull rod material CrWMn , 7 CrSiMnMoV , 40 Cr carry out the feasibility that TD processing and anticipate that effect. Cr12MoV, 7CrSiMnMoV material can be successfully applied to obtain 1800 ~ 3000HV TD processing the high hardness surface coating layer. Application of swelling Cr12MoV material (quenched), the pull rod material 7CrSiMnMoV (quenching) in vanadiμm primary permeability, surface chromizing, Nb multi-layer coated super-hard TD coating. Above reaching 10 times by the fact that the actual scene producing verification, are anticipated that effect, improves clamp product life time.4) Analysis of the application of PVD coating technology feasibility and effectiveness. Investigation the application results of PVD coating on different substrate materials with different bonding strength. Based on the smaller hardness difference, the smoother surface, and the stronger the binding force of the principle. According to PVD coating technology handicraft characteristic, demand base to experience and observe material coating face machine work smoothness above R0.4 and carries out polishing, the base material of tempering temperature above 500 degrees, quenching experiences and observes a hardness being able to satisfy the usage request above 50 HRC. TiCN may reduce the coating internal stress , the tenacity improving coating , the thickness increasing coating's , deter the crack irradiation from waiting for merit. Adopting TiN, TiC primer coating, multi-layer TiCN PVD coating technology on surface, the pull rod material CrWMn (quenching), swelling material Cr12MoV for PVD coated super-hard coating technology. Gain ideal effect above improving Fixture products life time reaching 10 times.This thesis is design and application of TD processing and PVD coating technology on core component of connecting rod machine tool fixture off pull rod and swelling surface treatment technology to strengthen the High-frequency hardening technology to replace the original method of improving wear resistance. Apply new materials and the new surface treatment technology, make fixture life time the above reaching original 10 times. To further enhance the quality of the equipment connecting rod basis, looking for new ways to make up for domestic equipment in the performance of connecting rod instability characteristics. Fracture splitting connecting rod technology is important for improving the motor industry in our country and impelling the industrialization course of the connecting rod manufacture technology.