Research On The Modeling Of Hydraulic Manifold Block In Virtual Assembly Environment

This research task is supported by 'Research on CAD of Hydraulic Manifold Blocks based on Intelligent Optimization and Virtual Design' (50375023) from National Natural Science Foundation of China.The assembly of hydraulic manifold block(HMB) is a process of assembling different kinds of hydraulic parts in the integrated block according to certain assembling relationship and function requirement, which under the condition of rational arrangement and layout of hole.The design of assembling relationship is not only the precondition and fundation of the inner hole connection but also the criteria of HMB inspection after processing. With the aid of CAD technique, virtual assembly can be carried out when it is still in the process of design. By analysis the result of virtual assembly, the assembly possibility can be validated, as result, the rationality and accurateness of external component and internal hole layout can be ensured and the process of checking interference goes easer.This task accomplishes the modeling job of HMB virtual assembly environment, which is based on MDT real-time interference checking. The main research of this dissertation is as follows:(1) By employing VC++6.0 development environment, ObjectARX took kit, MCAD API technique and Microsoft Access database, the secondary development towards AutoCAD Mechanical Desktop software, which is popular powerful 3D parameterized modeling software currently, is done. As a result, HMB virtual assembly automatic generation system is realized.(2) By analyzing application and status quo of virtual assembly technique, aiming at structure feature and assembly characteristic of HMB, the necessity of virtual assembly for manifold block is pointed out and the whole assembly process is divided into three courses: data preparation, modeling of virtual assembly and checking of design result.(3) By employing parameter entity modeling technique based on feature, applying data from data module of block body and component model, 3D model of hydraulic components are modeled. Model data is saved in paramedic component base, which provides visual support for virtual assembly design.(4) Assembly relationship data module is set up. By putting this module into use, match constraint between block body and component is set and thus assembly sequence layout is realized. Tree structure is employed to express assembly hierarchy, bottom-up hierarchical assembly pattern is adopted to fulfill the assembly job. In order to simplify calculation, enveloping box method is introduced for intervene checking, which is the main part of design result examination.(5) At last, by realizing a virtual assembly model for a typical hydraulic system example, the feasibility of this system is demonstrated.The automatic drawing of HMB virtual assembly model is the key part of manifold block CAD. Practice proves that this system is convenient for use and basically realizes the automatization of assembly model.