570 likes | 590 Views
授課教師: 楊宏智 教授. MANUFACTURING ENGINEERING TECHNOLOGY GENERAL INTRODUCTION. 【 本著作除另有註明外,採取 創用 CC 「姓名標示-非商業性-相同方式分享」台灣 3.0 版 授權釋出 】. 【 本著作除另有註明外,採取 創用 CC 「姓名標示-非商業性-相同方式分享」台灣 3.0 版 授權釋出 】. 【 本著作除另有註明外,採取 創用 CC 「姓名標示-非商業性-相同方式分享」台灣 3.0 版 授權釋出 】. MANUFACTURING ENGINEERING TECHNOLOGY 機械製造.
E N D
授課教師:楊宏智教授 MANUFACTURING ENGINEERING TECHNOLOGY GENERAL INTRODUCTION 【本著作除另有註明外,採取創用CC「姓名標示-非商業性-相同方式分享」台灣3.0版授權釋出】 【本著作除另有註明外,採取創用CC「姓名標示-非商業性-相同方式分享」台灣3.0版授權釋出】 【本著作除另有註明外,採取創用CC「姓名標示-非商業性-相同方式分享」台灣3.0版授權釋出】
MANUFACTURING ENGINEERING TECHNOLOGY機械製造 楊宏智(台大機械系教授)
CHAPTER OUTLINE What Is Manufacturing? Product Design and Concurrent Engineering Design for Manufacture, Assembly, Disassembly, and Service Green Design and Manufacturing Selection of Materials Selection of Manufacturing Processes Computer-integrated Manufacturing Quality Assurance and Total Quality Management Lean Production and Agile Manufacturing Manufacturing Costs and Global Competition General Trends in Manufacturing
WHAT IS MANUFACTURING? Application of physical and chemical processes to alter the geometry, properties, and/or appearance of a starting material to make parts or products.
MANUFACTURING - ECONOMIC Transformation of materials into items of greater value by one or more processing and/or assembly operations.
ECONOMIC IMPORTANCE U.S. Economy Sector:%GDP Agriculture and natural resources 5 Construction and public utilities 5 Manufacturing 15 Service industries 75 100
WHAT IS MANUFACTURING? Products around us consist of numerous individual pieces that shall be built and assembled: Clip – one part Lawn mower – 300 parts Grand piano – 12,000 parts Automobile – 15,000 parts Boeing 747-400 – 6 million parts
WHAT IS MANUFACTURING?EXAMPLE 1.1 Paper Clips Functional and Service Requirement -Clamping forces (stiffness,strength- permanent deformation; material select: shape and size) -Corrosion resistance Style and Cost -Metallic or plastic? What shape (round or else)? It’s dia? Surface finish? Production Consideration -How to shape (hand or machine)? Batch quantity -Bending without cracking or breaking -Easily cut without causing excessive wear on tooling -Produce smooth edge on the wire (burs not desire)
WHAT IS MANUFACTURING? Example 1.2 Incandescent Light Bulbs Component of a common incandescent light bulb
MANUFACTURING STEPS IN MAKING ANINCANDESCENT LIGHT BULB (PROD. RATE >1000/MIN) Filament manufacturing: Tungsten powder (sintering) – Ingot (swaging) –Rods (drawing)- thin Wire (60W, 0.045 mm dia) Wire dia. 1%less causes 25% life shortage (heated to 2200 to 3000 C) Bulb vacuumed or filled w N2 or Argon gas (water drop causes 0.5m blackened); coil spacing accuracy (heat concentration); position accuracy – heat deflection disk, and lead-in wire (Fe+Ni w Cu coating)= glass thermal expansion coefficient
PRODUCT DESIGN AND CONCURRENT ENGINEERING The Design Process Design and manufacturing activities take place sequentially
PRODUCT DESIGN AND CONCURRENT ENGINEERING The Design Process It would be more desirable to: Use a different material Use the same material but in a different condition Modify the design of a component Concurrent Engineering Also called simultaneous engineering From the earliest stages of product design and engineering, all are simultaneous
PRODUCT DESIGN AND CONCURRENT ENGINEERING Concurrent Engineering Any iterations will require a smaller effort and less wasted time would occur Market Specification Concept design Detail design Sell Manufacture
PRODUCT DESIGN AND CONCURRENT ENGINEERING Life Cycle Life cycle of a new product consists of: Product start-up Rapid growth of the product in the marketplace Product maturity Decline Life-cycle engineering requires that the entire life of a product be considered
PRODUCT DESIGN AND CONCURRENT ENGINEERING Role of Computers in Product Design Product models are simplified through computer-aided design (CAD) and computer-aided engineering (CAE) techniques CAD systems are capable of rapid and complete analysis of designs This is the process known as paperless design Performance of structures can be analysed
PRODUCT DESIGN AND CONCURRENT ENGINEERING Role of Computers in Product Design (Con’t) Computer-aided manufacturing involves all phases of manufacturing Performing tasks such as: Programming for numerical control machines Designing tools, dies, moulds, fixtures, and work-holding devices Maintaining quality control
PRODUCT DESIGN AND CONCURRENT ENGINEERING Prototypes A prototype is a physical model of an individual component or product Rapid prototyping use CAD/CAM and various specialized technologies Prototypes developed can review for possible modifications to the original design, materials, or production methods
PRODUCT DESIGN AND CONCURRENT ENGINEERING Virtual Prototyping It is a software-based method that uses advanced graphics and virtual-reality environments To allow designers to view and examine a part in detail Also known as simulation-based design
DESIGN FOR MANUFACTURE, ASSEMBLY, DISASSEMBLY, AND SERVICE Design for manufacture (DFM) integrate the design process with production methods, materials, process planning, assembly, testing, and quality assurance Design for assembly (DFA), Design for manufacture and assembly (DFMA), and Design for disassembly (DFD) are all important for manufacturing Assembly requires a consideration of the ease, speed, and cost of individual components of a product
GREEN DESIGN AND MANUFACTURING Manufacturing operations produce waste like: Chips from machining and trimmed materials Slag from foundries and welding Additives in sand used in sand-casting Hazardous waste and toxic materials Lubricants and coolants Liquids from heat treating Solvents from cleaning operations Smoke and pollutants from furnaces
GREEN DESIGN AND MANUFACTURING Environmentally conscious design and manufacturing considers all possible adverse environmental impacts of materials, processes, operations and products Design for recycling (DFR) - two basic activities 1) Biological cycle - Organic materials degrade and lead to new soil that sustain life 2) Industrial cycle - Product that can be recycled and reused continuously
GREEN DESIGN AND MANUFACTURING Cradle-to-cradle Production emphasizes: Sustainable and efficient manufacturing activities Waste-free production Using recyclable and nonhazardous materials Reducing energy consumption Using renewable energy Maintaining ecosystems Using available materials and energy sources Exploring the reuse and recycling of materials
GREEN DESIGN AND MANUFACTURING Guidelines for Green Design and Manufacturing Reduce waste of materials Reduce hazardous materials products and processes Investigate environmental-friendly manufacturing technologies Improvements in methods of recycling and reusing Minimize energy use Encourage recycling
SELECTION OF MATERIALS General types of materials used: Ferrous metals Nonferrous metals Plastics (polymers) Ceramics, glasses Composite materials Nanomaterials Shape-memory alloys, amorphous alloys, semiconductors and superconductors
SELECTION OF MATERIALS Properties of Materials Mechanical properties Physical properties Chemical properties Manufacturing properties Appearance
SELECTION OF MATERIALS Availability If materials are not available in the desired quantities, shapes, dimensions, and surface texture, substitute materials can be considered Reliability of supply is important in order to meet production schedules A country’s self-reliance on resources is a political goal
SELECTION OF MATERIALS Service Life A shortened service life of a product is due to: Improper selection of materials Improper selection of production methods Insufficient control of processing variables Defective parts or manufacturing-induced defects Poor maintenance Improper use of the product
SELECTION OF MATERIALS Material Substitution in Products We would want to consider the following substitutions: Metal vs. wooden handle for a hammer Aluminium vs. cast-iron lawn chair Aluminium vs. copper wire Plastic vs. steel car bumper Plastic vs. metal toy Alloy steel vs. titanium submarine hull
SELECTION OF MATERIALS Example 1.2 Baseball Bats Cross sections of baseball bats made of aluminium and composite material
SELECTION OF MATERIALS Example 1.3 U.S. Pennies Materials used undergone changes throughout history due to periodic material shortages and the cost of appropriate raw materials
SELECTION OF MANUFACTURING PROCESSES Some examples of manufacturing methods are: Casting Forming and shaping Machining Joining Finishing Microfabrication and nanofabrication
SELECTION OF MANUFACTURING PROCESSES Process Selection Selection of process depends on geometric features of the parts and workpiece material and properties Some mechanical tools are being replaced by laser cutting Size of manufactured productsare getting smaller such as microscopic gears
SELECTION OF MANUFACTURING PROCESSES Net-shape and Near-net-shape Manufacturing Part is made in only one operation to the final desired dimensions, tolerances and surface finish Difference between the two is the degree of how close the product is to its final dimensional characteristics Examples of net-shape manufacturing are precision casting, forging, forming sheet metal, powder metallurgy, injection molding of metal powders and injection molding of plastics
SELECTION OF MANUFACTURING PROCESSES Ultraprecision Manufacturing Advantages are dimensional accuracies and mirror-like surfaces on metals Types of Production Job shops: less than 100 Small-batch production: 10 to 100 Batch production: 100 and 5000 Mass production: over 100,000
SELECTION OF MANUFACTURING PROCESSES Example 1.4 Saltshaker and Pepper Mill The two metal pieces for the pepper mill are made by powder-metallurgy techniques
COMPUTER-INTEGRATED MANUFACTURING Computer-integrated manufacturing (CIM) integrates computer graphics, computer-aided modelling, and computer-aided design and manufacturing activities Capable of making possible Responsiveness to rapid changes Better use of materials, machinery, and personnel Reduction in inventory Better control of production and management
COMPUTER-INTEGRATED MANUFACTURING Various elements in CIM include: Computer numerical control (CNC) Adaptive control (AC) Industrial robots Automated materials handling Automated assembly systems Computer-aided process planning (CAPP) Group technology (GT) Just-in-time production (JIT) Cellular manufacturing (CM) Flexible manufacturing systems (FMS) Expert systems (ES) Artificial intelligence (AI) Artificial neural networks (ANN)
COMPUTER-INTEGRATED MANUFACTURING Example 1.5 Mold for Making Sunglasses Frames Machining a mold cavity for making sunglasses Computer model of the sunglasses as designed and viewed on the monitor Machining of the die cavity using a computer numerical-control milling machine
QUALITY ASSURANCE AND TOTAL QUALITY MANAGEMENT Product quality influences customer satisfaction Quality must be built into the product from its initial design Quality assurance and total quality management (TQM) are the responsibility of everyone involved in the design and manufacture of products and their components Product integrity define the degree to which a product Functions reliably Suits its intended purposes Can be maintained with relative ease
QUALITY ASSURANCE AND TOTAL QUALITY MANAGEMENT At six sigma, defective parts are reduced to only 3.4 per million parts made. Level reached only through manufacturing process capabilities to reduce variability in product quality Quality Standards Global manufacturing and competitiveness lead to international quality control methods Thus the establishment of ISO 9000 and QS 9000 standards
QUALITY ASSURANCE AND TOTAL QUALITY MANAGEMENT Human-factors Engineering Human-factors approach results in ergonomics design Defined as the study of a workplace and the design of machinery and equipment Product Liability Involved with product design, manufacture and marketing Product’s malfunction or failure can cause bodily injury or even death
LEAN PRODUCTION AND AGILE MANUFACTURING Lean production involves a thorough assessment of each activity of a company Lean production focuses on: Efficiency and effectiveness of each and every manufacturing operation, Efficiency of the machinery and equipment used Activities of the personnel involved in each operation
LEAN PRODUCTION AND AGILE MANUFACTURING Agile Manufacturing Agile manufacturing is ensuring agility and flexibility Methodologies of both lean and agile production require that a manufacturer benchmarks its operations
MANUFACTURING COSTS AND GLOBAL COMPETITION Manufacturing cost is about 40% of its selling price Total cost of manufacturing a product consists of: Materials Tooling Fixed Costs Capital Labour