apps等多个文件制造与装配process planning

1、Process PlanningProcess PlanningEngineering activity that determines appropriate procedure for transforrawmaterials into a final produspecified by engineering design.Process planning is concerned with determining the sequence of individual manufacturing operations needed to produce a given part or p

2、roduct.The resulting operation sequence is documented on a form typically referred to as a route sheet containing a listing of the production operations and associated machine tools for a workpartmanufacturingProduction instructionsed part and assembly informationproducts meeting required qualitydes

3、ignproduct2Manufacturing flowDrawingsSpecifications(parts and assembly)Process planningProduct designPreparatory tasks Material preparation Process design and fabrication Tooling design and fabrication Production scheduling Time standard estimating Quality control planningProduction documentPart man

4、ufacturingAssemblyTestingFinal product3Requirements for Process PlanningA process plan must ensure all the quality requirements of the part defined in the part drawing.A process plan should bring about reasonably high production efficiency in order to fulfill the production quota before its due date

5、.A process plan should ensure low production costs.A process plan should help improve the working conditions and promote the uninterrupted development of manufacturing technology.4Starting fromPart configuration Necessary and sufficient projections, sections, cutaway views and dimensionsTechnical sp

6、ecifications Tolerances Surface roughnessMaterial Type of material Heat treatment Hardness Detection of defects, if anyProduction volume Single-piece (job-lot) production Batch production (small, medium, large) Mass production Production equipment available Other information (assembly)5Tasks in Proc

7、ess PlanningProcess routing planningAnalysis of part drawing.Selection of machining methods and machining route for each part surface to be machined.Determination of the contents of each machining operation and the number of machining operations.Determination of the sequence of the operations.Select

8、ion of locating references for each machining operation.Arrangement of heat treatment operations. Arrangement of auxiliary operations.yyyyyyy6Tasks in Process PlanningMachining operation designSelection of machine tool and tooling for each machining operation.Arrangement of the sequence of operation

9、 elements in each machining operation.Determination of machining allowance for each surface to be machined in each operation.Calculation of operational dimensions and tolerances for each operation.Selection of machining conditions for each operation. Estimation of time standard for each operation.De

10、termination of operator skill requirements for each operation.yyyyyyy7Decisions which must be Wich machine should be used? How will the part be held in the machine? What cutting tools? What operations and strategy?:MaDecision based on: Experiencelection Available machines Number of parts in the orde

11、r (are they enough to justify higher setup cost and run cost on a more complex machine?) Is the part best suited for a lathe or a milling machine? Vertical/horizontal spindleFixturing selectionDecision on how the workpiece should be held:Standard holding devices (ex: chuck lathe) or special fixturin

12、gTo avoid vibrations, deflections, plastic deformationTo respect tolerancesTool selection Material WP material Production rate Cost Shape and size Angles Nose radiusf (mm/rev)V (m/min)Tool shapes2fRa =Nose radiusStandard values:32r0.4 - 0.8 - 1.2 - 1.6 - 2 - 2.4 mm14Increasing feedRoughness estimati

13、on6Conversion tableFeed estimation4Cutting parametersGrooves, cut-offGroovingComposition of Machining ProcessesOperation: A complete portion of the machining process for cutting, grinding, or otherwise treating a workpiece (or several workpieces simultaneously) at a single workplace.Operation elemen

14、t: A component of an operation that is performed without changing the cutting tool (or a group of simultaneously-used cutting tools), the machined workpiece surface, and cutting speed and feed.Pass (Cut): A single cutting motion of the cutting tool in the direction of the feed along the machined sur

15、face, without changing the setup of the tool, cutting speed, or feed.21Routing sheet22Routing sheet23Operation sheet24Operation sheetExample25Numerical Control Machine Tool“A Numerical Control machine is a machine positioned automatically along a pre-programmed path by means of coded instructions”FI

16、GURE 14.7 Schematic illustration of the major components of a numerical control machine tool.26Programfor Numerical ControlGeometric instructions: relative movements between tool and workpieceProcessing instructions: spindle speeds, cutting tools, cutting fluids,.Travel instructions: type of interpolation and speed of movement of the tool or the worktableSwitching instructions: on-off position for coolants,feeding, clam,.27PEPSPEPS