| In the research process of large manufacturing equipment,double column free forging hydraulic unit is considered to be one of the main development directions in free forging equipment because of its high efficiency,high mechanization degree and remarkable effect of energy saving and material saving.In this paper,by studying the stress of the main parts of the push free forging hydraulic press under the condition of partial load,the real restrictive factors of eccentric forging are clarified,which provides the basic theory for the further design of the working cylinder of the hydraulic press.Through the study of the mechanism of eccentric load of hydraulic press,it is found that the research results at home and abroad ignore the fact that the spherical hinge has the characteristics of self-locking performance.In this paper,the hydraulic presses of various types which have been put into operation in our country are analyzed and found that when the workpiece is forged in the maximum allowable forging eccentricity range,the ball hinges in the forging process are in the state of self-locking and will not rotate.Because the action of eccentric load is inevitable in the forging process,if the spherical joint structure rotates under the action of bias load,the frame bears the force produced by the partial load.However,under the actual working condition,the ball hinge will not rotate when the working cylinder and the frame each bear the role of eccentric load.Compared with the working cylinder,the working cylinder is obviously in the weak link,and the real restricting factor of eccentric forging of hydraulic press is the working cylinder.After it is clear that the working cylinder is the main component under eccentric load,the lateral thrust within the maximum allowable forging eccentricity is analyzed theoretically and the calculation method of lateral thrust is given.Because the effect of bias load is difficult to avoid,the main influencing factors of lateral thrust and its position are studied.Through the modeling and simulation analysis of the actual working conditions,the relationship between the contact stress of the guide sleeve in the working cylinder and the movement stroke of the plunger is obtained,and the influence of the lateral thrust action position on the contact stress of the guide sleeve is determined.Because the working cylinder is subjected to the lateral thrust caused by bias load,in order to ensure its safe use,it is necessary to improve its anti-bias performance to a certain extent.In the course of the research,it is found that the length of the guide sleeve can be increased by adjusting the gap between the guide sleeve and the plunger.The improved sealing device and guide sleeve structure can reduce the lateral thrust produced by bias load and improve its own ability to withstand bias load.Therefore,considering the influence of the working temperature of the whole hydraulic press,the specific calculation method is given todetermine the clearance of the guide sleeve.Considering the hidden danger of safety caused by hydraulic oil and guide sleeve weight in the process of sealing,a new design method for the design of sealing device is given,which provides a reference for the design and further optimization of the main cylinder of forging hydraulic press. |
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