Milan Cechura

DESIGN OF MECHANICAL FORGING PRESS WITH MAXIMAL FORCE IN SIDE CAVITY

This paper deals with design of crankshaft forging press for multi-cavity forging with maximal forging force in on of side cavities. As a tool was used optimization of structure, structural FEM analysis and geometrical modification of frame. Results are in more uniform stress distribution in whole structure of forging press. This design leads to optimized production and improved quality of final products. Forging press with this modification has higher durability and it has competitive advantage.

INFLUENCE OF CROSSHEAD GUIDE TO OFF-CENTRE LOAD OF FORGING HYDRAULIC PRESS

A majority of operations carried out in hydraulic presses for open-die forging involve off-centre loading. The resulting forces and moments are absorbed by the machine’s frame. This causes tilting of the frame, increased stress and, ultimately, low accuracy of the forging process. The magnitudes of forces and moments associated with the operation are an invariable and fundamental aspect of the process. Therefore, the engineering designer’s job is to find design solutions which best suppress the effects of the offcentre loading on the press and on its behaviour. The main criterion is to minimize the lateral forces produced by the tilting moments on the press. This means minimizing the distortion of the machine and the pressures on its guides, leading to longer life, and, finally, better dimensional accuracy of the forged parts. Although the moment imposed by the load will not change, the forces acting on the guides – which transmit the moment to the frame – can be reduced by setting the guide elements farther apart. We have therefore attempted to compare several guide configurations for the crosshead of a forging press.

SUCCESSFUL OUTCOMES OF COLLABORATION BETWEEN A UNIVERSITY-BASED RESEARCH AND DEVELOPMENT FACILITY AND A MANUFACTURING FACTORY

University facilities often have extensive technical equipment for complex high-accuracy engineering calculations. These facilities strive to verify their results in practice. Such an opportunity arose in collaboration between the Centre for Forming Machine Design Research (CFMDR, Centrum výzkumu konstrukce tvařecich strojů) and the company TS Plzen, which focused on a new design concept for a hydraulic press for open-die forging. This press was the CKV 120/140 type; built for and supplied to the company SUNAN.

INFLUENCE OF HYDRAULIC PRESS COLUMNS CONNECTION ON DYNAMIC PROPERTIES

This paper deals with possibilities of hydraulic press design optimization. Dynamical loading is deeply discussed here. Technological operation called high speed forging is often used on this kind of machines. This technology leads to vibrations of whole hydraulic press. It must be ensured, that the lowest natural frequency of the whole press is higher comparing with frequency of forging. In research was performed finite element analysis, which showed influence of design modifications.

COMPARISON OF TECHNICAL PARAMETERS OF FORGING ROLLS AND CROSS WEDGE ROLLING

It is necessary to improve parameters of forging lines, because it leads to higher productivity and minimization of costs during production process. This paper deals with parameters of modern preforming processes such as forging rolls and cross wedge rolling. These parameters are compared with respect to maximal forces, moments and total energy consumption necessary for production of identical part.