| Forging hydraulic press is a heavy machinery equipment in the machinery manufacturing industry.It is one of the symbols to measure the level and capacity of a country's machinery manufacturing.It occupies an important position in the national economy.With the rapid development of modern industry,all walks of life have put forward new requirements for large-scale free forgings in terms of specifications and quality.Improving the quality of forgings and increasing the service life of forgings,improving the accuracy of forgings,reducing the amount of machining and saving raw materials have become the inevitable trend of the development of forging hydraulic press.There are many factors affecting the accuracy of forgings.With the continuous study of control methods,the control accuracy has been gradually improved.But the traditional control methods mostly control the hydraulic system.The control of forging dimension accuracy also stops at the control of the stroke of the actuator hydraulic cylinder,ignoring the influence of the force and deformation of the forging hydraulic press frame on the dimensional accuracy of forgings,so the forging research is carried out.The deformation of hydraulic press frame and its compensation during the contro l process are of great significance to improve the dimensional accuracy of forgings.The main contents of this paper are as follows:Firstly,the research status of hydraulic press at home and abroad is investigated from three aspects: body structure,transmission system and control method.The advantages and disadvantages of traditional control methods are analyzed,and a compensation control strategy based on elastodynamics theory is proposed to improve the precision of forging size control.Secondly,taking the three-beam and four-column forging hydraulic press as the research object,the stress state is analyzed,and the dynamic model of the frame is established.Through the analysis of the dynamic model of the frame,the spatial position change law of the key nodes of the frame is obtained,and the functional relationship between the displacement sensor measurement value,the deformation of the frame and the actual forging size is established,which lays the theoretical foundation for the subsequent simulation and experiment.Finally,the mathematical model of the valve control system of 0.6MN forging hydraulic press is established based on the mechanism modeling method.Based on the 0.6MN forging hydraulic press test bench,the deformation of the frame at different positions of the moving beam and different boost speed is tested.The dynamic model is modified by experiments,the compensation judgment rules are established,and the compensation controller is designed to verify the compensation control stra tegy to improve the forging fluid.The feasibility of position control accuracy of press provides a reference for improving the dimensional accuracy of forgings. |
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