Supplement

SUPPLEMENT ESYMBOL 108 \f "Wingdings" \s 5Computer-Integrated Manufacturing

SUPPLEMENT ESYMBOL 108 \f "Wingdings" \s 5Computer-Integrated Manufacturing

Supplement

E

Computer-Integrated Manufacturing

A.Computer-Aided Design and Manufacturing

1.Computer-aided design (CAD); electronic system used to design products and parts

a.Replaces drafting by hand

b.Computer shows several views as designer creates the drawing

c.Stress analysis shows reaction to force, indicating where the design is weak or likely to fail

d.Successful designs are stored, building a library of designs that can be retrieved and reused

2.Computer-aided manufacturing

a.computers used to:

symbol 113 \f "Wingdings" \s 10 \hDesign production processes

symbol 113 \f "Wingdings" \s 10 \hSchedule manufacturing operations

symbol 113 \f "Wingdings" \s 10 \hTrack labor costs

symbol 113 \f "Wingdings" \s 10 \hSend instructions to control machine tools

symbol 113 \f "Wingdings" \s 10 \hDirect materials flow

3.CAD/CAM system

a.Integrates the design and manufacturing function

b.Translates the computer drawing or image into code, which directs and controls a machine to produce parts

B.Numerically Controlled (NC) Machines

1.Most commonly used form of flexible automation

a.One machine has many tools and performs many operations, perhaps machining a detailed part from a block of metal

b.Receives instructions from external source (tape or computer) [Mention CNC machines.]

2.Computerized numerically controlled (CNC) machines

C.Industrial Robots

1.Computer-controlled machines programmed to perform various functions

2.Limited reach

a.Increased travel or axes of movement rapidly increases price.

b.Robot must always know where it is relative to the work; precision depends on maintaining a reference point.

3.Usually sightless

a.Tools must be stored in predetermined locations.

b.Material must always be presented in the same orientation.

c.Some second-generation robots have sensors to simulate touch and sight.

4.Relatively slow speed (when compared to fixed automation)

symbol 113 \f "Wingdings" \s 10 \hUsually not suitable for high-volume standardized production

D.Automated Materials Handling

1.Materials handling processes cost time and money and add no value to the product

symbol 113 \f "Wingdings" \s 10 \hAlways look for ways to reduce materials handling

symbol 113 \f "Wingdings" \s 10 \hMaterials handling automation justification depends on flow strategy

SYMBOL 216 \f "Wingdings"With a flexible flow, materials handling automation is rarely justified

SYMBOL 216 \f "Wingdings"With line flow, materials handling automation may be justifiable

a.Automated Guided Vehicle (AGV)

symbol 113 \f "Wingdings" \s 10 \hFollow cable or optical (paint stripe) path

symbol 113 \f "Wingdings" \s 10 \hOnboard or centralized computer control

symbol 113 \f "Wingdings" \s 10 \hRoute around transportation bottlenecks

symbol 113 \f "Wingdings" \s 10 \hJust-in-time delivery of parts

b.AS/RS

E.Flexible Manufacturing System

1.Characteristics of FMS:

a.Large initial investment [$5MM to $20MM]

b.Little direct labor

c.Routing of operations determined by central computer

d.Short setup times

eDifferent machines can perform the same operation

2.Three Key Components of an FMS

a.Several computer-controlled work stations, CNC machines, or robots that perform a series of operations

b.A computer-controlled transport system

c.Loading and unloading stations

3.Strategic Uses of FMS

a.Intermediate flow strategy

b.Line flow processes where product life cycles are short

4.Flexible manufacturing cells

ANNOE1

124

125