ME430 Project PDF

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Summary

Project for ME 430 (Prof Herli Surjhanta)...

Description

BUTTERFLY VALE ASSEMBLY USING SOLIDWORKS

DRAWN BY: FOAAD HUSAIN MECHANICAL ENGINEERING DEPARTMENT

CAD systems: Computer Aided Design can be described as the use of computer software to design and document the designing the process. These softwares make use of graphical symbols which include but is not limited to points, lines curves, planes etc; CAD makes the designing process faster and more efficient. Objects in engineering are represented in the form of technical drawings also known as drafting that represents designs and specifications of the physical object and data relationships.Not only these softwares help in designing a particular model but they also provide features which helps with the analysis related to the model such as flow simulations , stress concentration graphs, motion study, etc; Not all engineers use the same CAD softwares, the CAD software used by an engineering firm depends on the products they deal with. There are CAD softwares that deals specifically with 2D drafting, then there are some that deals heavily with 3D modelling, 3D wireframe, surface modelling and solid modelling. The following are the most popular CAD softwares used for specific application area:

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AutoCAD, TurboCAD etc: used mainly for 2D drafting.

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SolidWorks, AutoDesk Inventor etc; for Solid Modelling.

Before an engineer can start using a CAD software the most important step is to understand the Graphic User Interface of that particular CAD software. The GUI of a CAD software basically is a communication medium between the user and the software. Two of the most important software used in the mechanical engineering world are SolidWorks and PTC Creo Parametric. Solidworks enables the designers to create a mathematically correct solid model and then store it in a database. Basically both solidworks and creo have the same features, its just that they have different GUIs and it depends on the requirement of the model. For example, if one has to make large assemblies CREO parametric is a great tool. Solidworks is much simpler when compared to CREO. This project concerns the use of solidworks.

Butterfly Valve Assembly: Butterfly valves are common in the industry and are used to interrupt the flow of fluid in any given process. The gas pedal of an automobile generally uses this valve to control the air that comes in and out of the engine. This project involved the modelling and assembly of different components of the valve. The parts that were modelled using solidworks include the butterfly, cover, rack housing , the butterfly housing and the butterfly shaft. Since solidworks design library offers nice range of small tools, some of the minor parts were taken from there and then their dimensions changed to match the need of the assembly. A major part of the project focused on the modelling of the parts and there were some solidworks features that had to be called more often than others. The most commonly used features for making the parts were definitely sketch, mirror geometry,extrude and extrude cut, revolved and revolved cut was used to make the butterfly shaft. The extrude cut feature comes in very handy when the drawing requires many hollow circular holes. Mirror geometry cuts off the time and effort of making the same thing over and over again and instead uses a mirroring plane to symmetrically offset the sketch at a desired location. The smart dimension option serves as a great tool to manipulate dimensions after sketch has been completed. The different parts created are then combined to make one big assembly. To perform the assembly of the parts, the assembly file needs to be opened and then one by one all the parts are inserted in the graphics area using the Insert Component option. The Mate feature allows to relate two parts in an assembly by means of constraints. Mates can be simple like concentric, coincident, tangent, etc; mates can also be mechanical. Some important mechanical mates in solidworks are Rack & Pinion, Cam follower, hinges etc; for this butterfly valve assembly the most used mates were concentric and coincident, rack and pinion mate was called for the rack and pinion subassembly.Sometimes it so happens that the parts after undergoing mating don’t sit that well due to wrong dimensions or maybe error while mating and that gives rise to interferences. Interference in CAD terms simply mean that two or more parts overlap each other and such an orientation is not possible in the real world.

Solidworks offers an interactive way to schematically show the materials and parts used in a certain assembly. This feature is known as the bill of materials and it generates a complete list of parts, sub-assemblies and sub-components used in an assembly. It is an easy way for an engineer to interpret the assembly with the help of the bill of materials. The bill of material is usually shown along with the detailed drawing of the assembly.

The Butterfly Valve Assembly:...