Transcript Design for Manufacture, Assembly, Disassembly, and Service
9/12/05
Manufacturing
Group #3
Erica Velarde David Pincus Sean Clifton Ruben Sosa
What is Manufacturing?
It is defined as, the process of converting raw materials into products.
The word manufacturing is derived from the Latin word
manu factus
meaning made by hand.
It usually involves activities in which the manufactured product is used to manufacture other products.
Products are seldemly made of just a single part, such as a nail or bolt. Most objects are constructed by assembling a number of single parts, and these components can be made from a variety of materials.
Number of Single Parts in Some Products
Rotary Lawn Mower Grand Piano Automobile C-5A transport plane Boeing 747-400 300 parts 12,000 parts 15,000 parts >4,000,000 parts >6,000,000 parts
Duratec V-6 engine components and materials used to manufacture them
Manufacturing is a complex activity that involves a variety of resources and activities: Product Design Machinery and Tooling Process Planning Materials Purchasing Manufacturing Production Control Support Services Marketing Sales Shipping Customer Service
Manufacturing Steps and Components of a Light Bulb
Manufacturing is a vital part of a nations economy. It is said that a nation’s level of manufacturing activity is directly related to its economic health; the higher the level of manufacturing activity in a country, the higher the standard of living of its people.
The History of Manufacturing
It dates back to about 5000 B.C.
It is older than recorded history Primitive cave and rock markings made with tools that were manufactured for these purposes.
Primitive manufacturing of products for various specific uses began with articles made of wood and stone.
Environmentally Conscious Design and Manufacture
Environmentally Conscious Design and Manufacturing Facts:
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In the United States alone, nine million passenger cars and about 300 million tires are discarded each year; about 100 million of those tires are reused in various ways.
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More than five billion kilograms of plastic products are discarded each year.
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Every three months, industries and consumers discard enough aluminum to rebuild the country’s commercial air fleet.
What Pollutes the Environment?
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Lubricants and coolants are often used in most manufacturing operations.
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Various fluids and solvents are used in cleaning manufactured products, some of these fluids pollute the air and water during their use.
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Many by-products from manufacturing plants have been discarded for years (i.e., sand containing additives used in metal-casting processes; water, oil and other fluids from heat-treating facilities and from planting operations; slag from foundries and from welding operations.)
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A variety of metallic and non-metallic scrap, produced in operations such as sheet forming, casting and molding.
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The effects of these activities, their damage to our environment and to the earth’s ecosystem, and, ultimately, their effect on the quality of human life are well recognized.
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Major concerns are water and air pollution, acid rain, ozone depletion, the greenhouse effect, hazardous wastes, landfill seepage and global warming.
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Many laws have been set in place in the United States and other industrialized countries to help reduce the pollution.
What Can We Do?
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Reduce waste of materials, by refinements in product design and reducing the amount of materials used Reducing the use of hazardous materials in products and processes.
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Conducting research and development into environmentally safe products and into manufacturing technologies.
Ensuring proper handling and disposal of all waste.
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Making improvements in recycling, waste treatment and reuse of materials.
Computer-Integrated Manufacturing What is computer-integrated Manufacturing (CIM)?
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Software and hardware are integrated from product concept through product distribution in the marketplace.
Why is it effective?
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Responsiveness to rapid changes in market demand and product modifications.
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Better use of materials, machinery, and personnel, and reduction in inventory.
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Better control of production and management of the total manufacturing operation.
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The manufacturing of high quality products at low cost.
Major Applications of Computers in Manufacturing
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Computer Numerical Control (CNC): Method of controlling the movements of machine components by direct insertion of coded instructions in the form of numerical data.
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Adaptive Control (AC): The parameters in a manufacturing process are adjusted automatically to optimize production rate and product quality, and to minimize cost.
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Automated Handling of Materials: Computers have made possible highly efficient handling of materials and components in various stages of completion, such as when being moved from storage to machines, from machine to machine, and at points of inspection, inventory and shipment.
Industrial Robots: introduced in the early 1960s, industrial robots have been replacing humans in operations that are repetitive, dangerous and boring, thus reducing the possibility of human error and improving productivity. Robots with sensory perception capabilities have been developed with movements that simulate those of humans.
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Automated and Robotic assembly systems: These systems mainly have replaced costly assembly by human operators, although humans still have to perform some of these operations. Products are now designed or redesigned so that they can be assembled more easily and faster by machines.
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Computer-Aided Process Planning (CAPP): This system is capable of improving productivity by optimizing process plans, reducing planning costs and improving the consistency of product quality and reliability.
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Group Technology (GT): The concept of group technology is that parts can be grouped and produced by classifying them into families, according to similarities in design and similarities in the manufacturing processes employed to produce the parts.
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Just-In-Time Production (JIT): The principal of JIT is that supplies of raw materials, parts and components are delivered to the manufacture just in time to be used, parts and components are produced just in time to be made into subassemblies and assemblies and products are finished just in time to be delivered to the comsumer.
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Cellular Manufacturing (CM): This system utilizes workstations that usually contain several production machines controlled by a central robot, each machine performing a different operation on the part.
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Flexible Manufacturing Systems (FMS): These systems integrate manufacturing cells into a large unit, all interfaced with a central computer.
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Expert Systems (ES): These systems basically are complex computer programs; they have the capability to perform various tasks and solve difficult real life problems much as human experts would.
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Artificial Intelligence (AI): This important field involves the use of machines and computers to replace human intelligence. Computer controlled systems are now capable of learning from experience and of making decisions that optimize operations and minimize costs.
All of these help keep production costs down and also speed up the manufacturing process.
Lean Production and Agile Manufacturing What is it?
Lean Production: A methodology that involves a thorough assessment of each of the activities of a company in order to minimize waste at all levels.
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These include the efficiency and effectiveness of all its operations, the efficiency of the machinery and equipment, the number of personnel involved in each operation and the possible dispensing of some of its operations and managers.
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This approach continues with a comprehensive analysis of the costs of each activity, including those due to productive and nonproductive labor.
Agile Manufacturing: A term indicating the implementation of the principles of lean production on a broad scale.
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The principal behind agile manufacturing is ensuring agility in the manufacturing enterprise, so that it can respond rapidly to changes in product demand and in customer needs.
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This flexibility is to be achieved through people, equipment, computer hardware and software and advanced communication systems.
Design for Manufacture, Assembly, Disassembly, and Service (DFMA)
What is DFM?
Design for Manufacture – integrates the design process with materials, maufacturing methods, process planning, assembly, testing and quality assurance.
Considerations
Characteristics, capabilities, and limitations of materials Manufacturing process Machinery Equipment Machine performance Dimensional accuracy Surface finish Processing time Effects of processing method on part quality
Design for Assembly (DFA)
Requires consideration of ease, speed, and cost of putting all the parts together.
Disassembly must also be possible for good design.
Easy assembly = easy disassembly
Benefits of DFA
Easy disassembly makes for easy service of parts.
Software is available to expedite the process and minimize cost.
The end result is Design for Manufacture and Assembly (DFMA)
Methods of Assembly
Fasteners or adhesives Welding, soldering, brazing
Methods of Assembly (cont.)
Hand/Machine assembly?
# of parts Amount of care/protection required Cost of labor
Selecting Materials
Properties, Cost & Availability, and Service Life
Types of Material
Ferrous metals Nonferrous metals Plastics (Polymers) Ceramics, glass, diamond Composites Wood
General Manufacturing Characteristics of Various Alloys
Alloy *Aluminum *Copper *Gray cast iron *White cast iron *Nickel *Steel *Zinc Castability E G-F E G F F E Weldability F F D VP F E D Machinability E-G G-F G VP F F E
Note:
E, excellent; G, good; F, fair; D, difficult; VP, Very Poor
Types of Material (cont.)
Nanomaterials Shape-memory alloys Amorphous alloys Semiconductors Superconductors, etc.
Properties of Materials
Mechanical – strength, toughness, ductility hardness, elasticity, fatigue, etc.
Physical – density, specific heat, thermal expansion, conductivity, melting point, and electrical/magnetic properties The combination of Mech./Phys. Properties give us strength-to-weight ratios (Important to aerospace) Chemical – oxidation, corrosion, general degradation, toxicity, flammability Manufacturing – determines if can be cast, formed, etc.
Cost and Availability
Depends on Reliability of Supply and Demand for Material Specialized machinery Extensive Labor Personnel with special skills/training
Appearance, Service Life, and Recyclability
Color, feel, surface texture Wear, fatigue can affect performance and service life Consideration for disposal after end of service life Ex. Baseball bats
Selecting Manufacturing Processes
Casting
– Expendable/Permanent mold
Forming/Shaping
– Rolling, forging, etc.
Machining
– Turning, milling, grinding, etc.
Joining
– Welding, adhesive, mechanical
Finishing
– Honing, lapping, polishing
Nanofabrication
– NEMS operate on the same level as biological molecules
Selecting Manufacturing Processes (cont.)
Depends on: shape to be produced and its properties Dimensional Accuracy & Surface Finish Operational & Manufacturing Costs
Consequences of Improper Selection of Materials and Processes
Temperature
Dimensional changes; surface oxidation; warping
Design and cost for tooling – tool/die life
Availability of equipment; experience of personnel
Pollution
Affects job safety and cost
Consequences
It stops functioning It does not function properly or within specs It becomes unreliable or unsafe to use
Net Shape Manufacturing
The first operation made on the part is made as close to the final dimensions, tolerances, surface finish, and specifications as possible.
Quality Assurance and Total Quality Management
What is Quality Assurance?
Most important aspect of manufacturing Influences the marketability of a product Influences customer satisfaction
Product integrity
Is the term usually used to define a product Is the product suitable for its intended purpose Does the product meets the market demand Does the product performs reliably during its life expectancy Can the product be maintained with relative ease
Example of Quality Assurance. The Little giant latter system.
Total Quality Management
Is the responsibility of everyone involved in design and manufacturing a product Management commitment to product quality Pride of workmanship at all levels of production Use of statistical process control (SPC) and the use of control charts for on-line monitoring of part production
Control chart is a device for describing in a precise manner what is meant by statistical control. It is a proven technique for improving productivity It is effective in defect prevention It prevents unnecessary process adjustments It provides diagnostic information It provides information about process capability
Example of control chart
Why do we care about quality Assurance and total Quality management?
Product Liability
Product malfunctioning Laws and regulations Human factor As engineers we have the responsibility to design and manufacture safe products that meet the public demand
Human Factor
It is impossible to totally eliminate a product safety hazard.
Human versus machine interactions A chainsaw A table saw A car lift
References
Kalpakjan and Schmid. Manufacturing Engineering and Technology. 5 th ed. Pearson Education Inc. 2006 Lindbeck. Product Design and Manufacture. Prentice-Hall, Inc. 1995 http://en.wikipedia.org/wiki/Industrial_robot http://www.engineering.com
http://www.encarta.msn.com
http://www.hotdot-bullseye.com/Taguchi.html
http://www.skymark.com/resources/leaders/juran.asp
http://reliability.sandia.gov
https://bigdealsnetwork.com/littlegiantladder/view_product.php?prod
uct=LG-10101
Questions 1. Which of the following is not a major application of computer in manufacturing: a. Computer Numerical Control b. Adaptive Controls c. Industrial Robots
d. Quality Control
2. Total quality management relates to: a. Commitment to product quality b. Pride of workmanship at all levels of production c. Identifying sources of quality problems
d. All of the above
3. The history of manufacturing dates back to: a. 1800
b. 5000BC
c. 1910 d. 1600 4. Which is not a method of assembly: a. Mechanical fasteners b. Welding
c. Wrapping
d. Adhesive 5. Net shape manufacturing involves:
a. Manufacturing the part as close to final tolerances as possible
b. Manufacturing the part in as many pieces as possible c. Manufacturing the part as quickly as possible d. Manufacturing the part as cheap as possible