U.S. Leadership in Manufacturing A Symposium at the Eighteenth Annual Meeting, November 4, 1982, Washington, D.C., National Academy of Engineering. (1983) / Chapter Skim
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Session 1: New Manufacturing Technologies
Session 1: New Manufacturing Technologies
Pages 59-90
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From page 59... ...
And we are at present blessed with the most powerful data processing equipment that has ever been known. The medium by which we will be reintegrating our industry is obvious.
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From page 60... ...
The challenge is to operate economically in the face of smaller lot sizes, shorter product cycles, greater model proliferation, socioeconomic pressures, and political realities. Fortunately, the crescendo of change confronting today's manufacturing manager is accompanied by the rapid emergence of technological options that can provide the flexibility and fast response time needed to meet the challenges.
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From page 61... ...
It is the close interdependence, the symbiotic relationships within the fabric of discrete-parts manufacturing, that makes it so susceptible to chaos. But diverse as the various parts of manufacturing may seem, there is a common element governing all manufacturing activities: What we call manufacturing is, in the ultimate analysis, a series of data processing operations or data transformations.
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From page 62... ...
Starting with the geometric model of a prototype, CAE uses the computer early in the design process to simulate performance of the proposed product. More directly related to manufacturing, numerically controlled (NC)
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From page 63... ...
By helping to identify select similarities, GT can provide considerable benefits for most of the functional areas in a manufacturing organization: product engineering, manufacturing engineering, production control, and procurement. In product engineering, GT can reduce part proliferation, encourage design standardization, provide manufacturing feedback, and facilitate cost estimating.
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From page 64... ...
Closely related to GT and another key factor in effecting computerintegrated manufacturing is computer-aided process planning. A planner must manage and retrieve a great deal of data and many documents, including established standards, machinability data, machine specifications, tooling inventories, stock availability, and existing process plans.
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From page 65... ...
The logic is based on a combination of past practice and basic technology. Another fundamental requirement for computer-integrated manufacturing Is an effective manufacturing control and manufacturing planning system.
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From page 66... ...
66 FIGURE 4 Robot loading machine, part of a flexible manufacturing system. FIGURE 5 Flexible manufacturing system at Mazak machine tool factory near Cincinnati.
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From page 67... ...
Tool storage capacity of l20 tools is divided among four interchangeable carousels. Control is the key to any flexible manufacturing system and is achieved, particularly at the machine level, with computer numerical control (CMC)
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From page 68... ...
In summary, the flexibility and fast response needed to meet the challenge of constant change facing manufacturing must be addressed on two levels. First, organizational computer-based technologies, such as group technology, and automated process planning, must transform the organized chaos of manufac- turing into continuous-process-like, fast-response systems.
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From page 69... ...
ASSEMBLY Joseph F Engleberger Our keynote speakers both referred to robotics.
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From page 70... ...
70 FIGURE l Rotary index machine. ROTARY INDEX MACHME or he wants it round, he wants gas gauges, he wants "idiot lights"; so every model auto needs a special speedometer assembly.
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From page 71... ...
7l FIGURE 2 Group technology manufacturing system. What are the economic issues?
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From page 72... ...
72 that scene. This eye, then, is in the palm, and the palm essentially roams over the workpiece to examine what is happening in that scene, what is different about this set of parts.
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From page 73... ...
That is called the "bin picking problem" or, among the technical types, the "occulsion problem." It has not been solved. Joseph Harrington and I were talking earlier about a grave manufacturing deficiency.
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From page 74... ...
74 TABLE l U.S. Export Competitiveness Hourly Compensation Country ($ U.S.)
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From page 75... ...
75 say, "Oh, we do assembly on one shift. There is no economic justification for robots.
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From page 76... ...
TESTING AND QUALITY Susan Foss The introduction of global products within our marketplace has taught us a valuable lesson: that we cannot sell a product based on price alone. Quality in the product gives the competitive edge.
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From page 77... ...
As known today, it operates in the design, manufacturing, and some concept and assembly stages. Closed-loop inspection provides dimensional history of machine tools and/or parts.
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From page 78... ...
It provides Deere with a rapid and accurate means of obtaining a data base for parts and machine tool dimensional data and also provides analysis routines to assist in interpreting this data. CAIR operates in l6 North American and 3 European facilities.
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From page 79... ...
79 • Engine test cells • Theodolites, which are surveyors' electronic transits used in place of measurement machines for measuring large frames and fixtures • Booms on excavators or frames for large motor graders Typical output devices include: • Printers and cathode ray tubes (CRTs) for analysis and/or inspection reports
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From page 80... ...
80 • And within one year, direct feedback to the machine tool CAIR offers, in addition to an inspection report, a series of analysis programs or routines to assist with data interpretation. These routines can on-line, real-time analyze the "just captured" data from the operating process and instantly display the results on the CRT or printer.
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From page 81... ...
It alone has provided substantial cost avoidance by significantly reducing delays encountered with machine tool deliveries. Daily use of this routine is made to monitor existing manufacturing processes and provide process control information.
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From page 82... ...
A typical VSM system consists of • Cathode ray tubes for input • Mainframe computer • Printers and CRTs for analyzing results Variation Simulation Modeling operates in the following manner: WATER PUMP SEAL PRESSURE SIMULATION VSM C> • OU»F(0 81J4 LOGIC • A mathematical model is constructed that establishes the relationship between the components of the assembly and imitates the assembly operation involved in putting the components together. This model describes the relationship between the parts of the system and how the system operates on the parts.
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From page 83... ...
• The use of these density functions allows the random selection of component dimensions by having a random number generator pick a number between 0 and l (such as 0.5843) and generate an associated component dimension based on its nominal values and tolerances.
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From page 84... ...
Once this variable or variables are determined, they are held at their nominal values by eliminating the random selection process, and the model is rerun, the object being to make percentage out of spec equal to zero. For the design engineer, VSM • Provides a substantial cost avoidance during concept/design and process stages Ensures correct tolerance interactions Aids with assigning tolerances Makes the probablistic approach practical Minimizes potential quality problems Reduces prototype builds For the manufacturing engineer, VSM • Provides substantial cost avoidance during concept/design and process stages • Minimizes potential quality problems • Aids process change decisions • Aids machine tool decision • Ensures a smooth flow from design through process stages The benefits of VSM are many.
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From page 85... ...
and/or parts, VSM provides compatibility of design and processes, and CAD/CAM provides a consistent base for part definition. The competitive edge against global products within our marketplace begins with quality, be it in the agricultural, the automotive, or even the aircraft industries.
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From page 86... ...
For the business systems we used an off-the-shelf data manager, but for geometry we were unable to find a commercial data base manager, and it became necessary for us to develop and build a geometric data base that would handle all of the coordinate systems, the centerline data, preliminary geometry, and our master models. We also created some cases in which, from a surface program, we could generate a mathematical surface definition that could then be automatically fed to a machine tool that would in turn create our wind tunnel models.
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From page 87... ...
When the go-ahead for a new product was given, we would extract the data that preliminary design had stored and start from that baseline to develop a more production-oriented model. We gave the engineer local storage space and his own stress analysis and fatigue analysis programs.
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From page 88... ...
The communication gap between the manufacturing engineer and the product design engineer is probably the most difficult thing that has to be dealt with in total integration of manufacturing systems. In the fabrication of detail parts, the common data base has proved to be extremely valuable.
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From page 90... ...
Session 2 participants. Left to right (standing)
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