The Study And Design On Clamping Mechanism In Heavy-duty Forging Manipulator

The level of research and application of heavy-duty forging manipulator reflects competitiveness of a country's high-end equipment manufacturing. The heavy-duty forging manipulator is a kind of special industrial robots that highly integrated machine, electricity and liquid. And multidisciplinary crossover design is one of the important characteristics of forging manipulator design; its design follows all the main points of general mechanical equipment design, and is more complex and special than other equipment for its special working conditions.In this paper, taking droop angle, jaw friction factor, jaw rotation angle and other parameters as control variables, the experimental platform of clamping mechanism was designed to verify theoretical model of jaw clamping force, which is established based on droop angle of forging. The experiments indirectly verified accuracy of the model by verified relationships between two non-structural factors?forging droop angle and jaw friction factor? and jaw clamping force and clamping performance. The experimental results are in agreement with theoretical results, illustrates the accuracy of the theoretical model.At the same time, the experimental results show that droop angle has an obvious effect on determination of jaw clamping force; if forgings are allowed with a certain droop angle can significantly reduce the force. The frictional contact state between jaw and forging also has an important influence on jaw clamping force and clamping performance. Under the premise of meeting strength requirement, the jaw material replacement for cast iron to increase friction coefficient, will effectively reduce jaw clamping force and improve clamping performance.On the basis of above theoretical and experimental studies, the effects of droop angle on force transmission ratio and clamping cylinder pressure are studied. Considering rotational position of jaw, the droop angle, diameter of forging and other factors, the calculation method of force transmission ratio is revised, and the calculation accuracy of output force of clamping cylinder is improved. The structural characteristics of clamping mechanisms are studied, and principles of these characteristics are analyzed in detail, which provide a reference for study of new design scheme.On the premise of restriction of drive angle and radius of rotation, the concept of limit position of the clamping mechanism is presented, and then actual working area and limit position area of the clamping mechanism are defined. The specific implementation of the design idea is to determine best position of the limit location area with respect to the actual working area, so that overall force transmission ratio of clamping mechanism to smallest, and accordingly the size of the parameters??, L₁, L₂? are determined. For other main dimensions?S₁, S₂, L₃? of the clamping mechanism, take the quantitative design method according to its position in space structure and correlation with other dimensions. In order to verify rationality of new design scheme, redesigned and processed clamping mechanism of existing experimental platform. And static clamping performance of original clamping mechanism and redesigned clamping mechanism are theoretically and experimentally studied. And dynamic clamping performances of two clamping mechanisms are carried out by the contrast experiments. Both theoretical analysis and experimental results show that the static and dynamic clamping performance of redesigned mechanism is better than that of original mechanism, which shows rationality and validity of the new design scheme.