Research On Parametric Drawing System Of Rolling Stock Axles

To improve the design and drawing efficiency of rolling stock axles, Auto Lisp and Visual Basic program is used in this paper, the theory and method of railway vehicle axles designing and parametric drawing systems is explored.The method and technical process of axle design is established. Four types of railway vehicle axle and wheelset are summarized, including the axle of freight car with tread brake, the wheelset of trailer with axis disc brake, the wheelset of trailer with axle/wheel disk brake and the driving wheetset with shaft disk brake. Based on these four types of railway vehicle axle and wheelset, the inertia Newton mechanics model is established according to the structure and mechanics relationship. Considering the general situation that the force transmit from adapter to wheelset is not through their central axis, it not only conforms to the existing standard, but also can reflect real wheelset for loading. Basic on the model, the method that compute the wheel load and the comprehensive moment of the axle key section is built. Combined with the axle design allowable stress, the process is built, which confirms the sizes of axle minimum section and checks the designing result.Based on the idea of modular software development, axles design and parametric drawing module are worked out. Axle design module contains four design modules that correspond with four types of railway vehicle axle and wheel. In accordance with the design process, vehicle input parameters module and the selected of axle module are prepared; the module to calculate axle radial size is prepared by wheel counterbalance system and the standard allowable stress. The module to determine the axle axial dimension is prepared according to vehicle parameters, axle box device parameter, wheel and brake disc parameters. Parametric drawing module contains seven kinds of axles engineering drawing, they are overall axle drawing module; axle transition arc drawing module; left view sectional drawing module; the drawing module of machining center hole and the hole to fix shaft cover; dimensioning modules; tolerance and roughness marking module and the additional information module including technical requirements, design drawing units, time, etc.The interface design techniques Visual Basic is used to achieve the development of railway vehicle axle interactive interface; the Auto LISP language is invoked to write drawing program of engineering drawing, the size-driven approach is used and the geometric model is changed consisting of topological and geometic constraint relations parameter constrains; Access database technology is used to manage the parameters of axles, then the parametric drawing of axles was achieved, and the various modules of the software and corresponding functions are shown.The designed and drawing cycle of axle in database is shortened by the system, which also provides a reference method for the study of other axles and promotes the research on the areas axle strength, dynamic performance, etc. So the project has a certain significance.