Research On The Maximum Allowable Forging Eccentricity Of The Pull-Down Double Column Free Forging Hydraulic Press

Double column free forging hydraulic press has such observably advantages as high efficiency,high degree of mechanization etc,which has become the major development direction in free forging equipment industry.By the structural features of the double column free forging hydraulic press can be fall into two major categories,one is the push-down structural and the other is pull-down structural.This thesis aims at double column pull-down free forging hydraulic press,researching on its eccentric load resisting performance.In the process of the free hydraulic press forging workpiece,there inevitably appears the state of eccentric load on account of multi-factor such as forging technology,the error of workpiece feeding,the shape of the workpiece,temperature departure,material non-uniform and so on.With the state of eccentric load,forging hydraulic press' s biggish working load has an nonnegligible impact on force-summing element.Unreasonable condition of eccentric load will shorten the element's service time,and seriously impact the working performance of forging hydraulic press.Therefore,the double column free forging hydraulic press has a higher request for the eccentric load resistance.The maximum allowable forging eccentricity is the important parameter to measure the eccentric load resistance of the forging hydraulic press.With the traditional method of studying hydraulic press' eccentric load resisting performance by ignoring self-lock condition of the working cylinder plunger and the connecting spherical hinge of walking beam,the constraints of hydraulic press' eccentric forging could hardly be represented,causing potential safety hazard to the equipment's application.The thesis under the process requirements of free forging,that analyzed and identified rigid connection between working cylinder's plunger and the rack should be met,while forging hydraulic press was working.Theoretically analyzed condition of single spherical hinge's self locking,inferred the computing method of spherical hinge's friction circle radius.Identified the plunger and the rack connection was rigid when spherical hinge was qualified to self locking.With the state of eccentric load,the eccentric load of pull-down double column free forging hydraulic press mechanical model is established,which based on spherical hinge connected between the plunger and the rack self locking.It researched the mechanism of eccentric load of forging hydraulic press,and analyzed the relation with spherical hinge's friction circle radius and allowable forging eccentricity.Aiming at the guide device of forging hydraulic press,confirmed the column of the rack and the guide device keep not constrained.And the function of the guide device was analyzed,the guide device impacting on the forging hydraulic press working process was researched and proposed the method that determine the gap of the guide device.On the basis of forging hydraulic press mechanical model,analyzed eccentric load delivery,and identified that the working cylinder and the rack bear all of theeccentric load.Theoretically analyzed the stress condition of the working cylinder and the rack under the action of the eccentric load.Combined with the information of existing double column pull-down free forging hydraulic press,calculated the stress of the working cylinder and the rack,and simulated analyzed the working cylinder and the rack in the state of eccentric load.Through study of theoretical computation simulated result,confirmed that the eccentric load resisting performance of the working cylinder was relatively weaker,which indicated that the working cylinder was the pivotal of eccentric load resisting performance and week factor.With the warranty of working cylinder operation,identified the control strategy of eccentric load.Researched the relationship between the condition of spherical hinge's self locking and eccentric load resisting performance of working cylinder,and then though of the condition confirmed the maximum allowable forging eccentricity.In conclusion,provided theoretical foundation for physical design of double column pull-down free forging hydraulic press.