Design And Optimization Of Hydraulic Nut Structure For Spindle System Of Continuous Extrusion Machine

Continuous extrusion technology is mainly used in the processing of line,strip,rod,plate and various profiles.It is a plastic processing method widely used in non-ferrous metal industry.Continuous extrusion machine is a special equipment for continuous extrusion production,in which hydraulic nut is the core component of the spindle system of continuous extrusion machine.The main function of hydraulic nut is to produce axial pre-tightening force on the mandrel during assembling of the spindle system of continuous extrusion machine,makes the parts such as sleeve and extrusion wheel contact closely,and produces enough friction force to transmit torque through mutual pressure.At present,the hydraulic nuts have the following shortcomings:because the hydraulic nut filling pressure is super high oil pressure(generally more than 200 MPa),if the hydraulic nut seal ring suddenly fails in the process of assembling and disassembling the spindle system,the instantaneous leakage of the super high pressure hydraulic oil will easily cause damage to the operators around.If the sealing ring of the hydraulic nut fails completely when it is locked,the filling pressure can not be established,which will lead to the locking of the whole spindle system can not be disassembled.Owing to hydraulic nuts work at a high pressure,the material requirements for the manufacture of hydraulic nuts are very high,and each spindle system needs to install a hydraulic nut,but except for assembling and disassembling the spindle system,hydraulic nuts only play the same fastening role as ordinary mechanical nuts.But the cost of hydraulic nuts is much higher than ordinary mechanical nuts,which improves the production and application cost of continuous extrusion machine.In view of the above shortcomings of hydraulic nuts,the main research work of hydraulic nuts in the spindle system of continuous extrusion machine is as follows:1.Finite element simulation.For the first time,the finite element model of the spindle system of continuous extrusion machine including hydraulic nut structure is established.After the finite element simulation of the spindle system,the stress of the important parts is analyzed,and the structure of the key parts is optimized.2.Experimental verification.In order to verify the reliability of the finite element simulation results and the rationality of the new structure,the optimized structure is processed,the experimental scheme is designed,and the stress of the new structure is tested by electrical measurement of resistance strain.3.Structural design and optimization.In view of the existing shortcomings of hydraulic nuts,the original structure is optimized and a new structure is designed to improve the safety of assembling and disassembling the spindle system,solve the problem that the seal failure of hydraulic nuts leads to the spindle locking and can not be disassembled,and reduce the production and application cost of continuous extrusion machine.