Parametric Computer Aided Hydraulic Cylinder Design: Piston Component Modeling

Abstract

Abstract In this work a procedure for parametric computer aided design of hydraulic cylinder pistons has been developed. Such a piston is a kind of component that has a geometry that is dependent and determined of surrounding and interacting parts. The piston seal has a very strong influence on the piston geometry, and the kind of piston design rules that can be found in piston seal catalogues have been used in the developed computer programs. The design procedure is divided in two parts. In the piston family design part, a piston family product model, which is common for a group of pistons with different dimensions but uses the same seal cross section, is created and stored in a piston family product model data base. In the member design part the piston family data is retrieved, dimension determining parameters are given, and one particular piston of a certain size is created and presented. The software system needed in order to be able to apply the suggested procedure consists of - a CAD-system, containing a graphic application program language - a specific CAD-system dependent interface program written in the graphic application program language - two CAD-system independent interface programs written in a common high level language lite FORTRAN - CAD-system independent product model data bases All these programs except the CAD-system have been developed in this work, and the use of the programs is demonstrated with an example.