Page 50 - 04. Subyek Engineering Materials - Manufacturing, Engineering and Technology SI 6th Edition - Serope Kalpakjian, Stephen Schmid (2009)

General Introduction

parts (based on similar parts made previously) can be produced efficiently and
economically.
_lust-in-time production (]IT). The principle behind ]IT is that (1) supplies of
raw materials and parts are delivered to the manufacturer just in time to be
used, (2) parts and components are produced just in time to be made into sub-
assemblies, and (3) products are assembled and finished just in time to be de-
livered to the customer. As a result, inventory carrying costs are low, defects in
components are detected right away, productivity is increased, and high-quality
products are made at low cost.
Cellular manufacturing (CM). This system utilizes workstations that consist of
a number of manufacturing cells, each containing various production ma-
chines controlled by a central robot, with each machine performing a different
operation on the part, including inspection.
Flexible manufacturing systems (FMS). These systems integrate manufacturing
cells into a large production facility, with all of the cells interfaced with a cen-
tral computer. Although very costly, flexible manufacturing systems are capa-
ble of producing parts efficiently, but in relatively small quantities, and of
quickly changing manufacturing sequences required for different parts.
Flexibility enables these systems to meet rapid changes in market demand for
all types of products.
Expert systems (ES). Consisting basically of complex computer programs,
these systems have the capability of performing various tasks and solving diffi-
cult real-life problems, much as human experts would, including expediting
the traditional iterative process in design optimization.
Artificial intelligence (AI). Computer-controlled systems are now capable of
learning from experience and of making decisions that optimize operations
and minimize costs, ultimately replacing human intelligence.
Artificial neural networks (ANN). These networks are designed to simulate the
thought processes of the human brain, with such capabilities as modeling and
simulating production facilities, monitoring and controlling manufacturing
processes, diagnosing problems in machine performance, and conducting fi-
nancial lannin and mana in acom an Y ’s manufacturin strate gi’ _
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EXAMPLE l.5 Mold for Making Sunglasses Frames
The metal mold used for injection molding of plastic path followed by the center of rotation of the machine
sunglasses is made on a computer numerical-control spindle). The numerical-control programming software
milling machine, by using a cutter (called a ball~nosed executes this machining program on the milling
end mill), as illustrated in Fig. 1.11. First, a model of machine, producing the die cavity with appropriate
the sunglasses is made using a computer-aided design dimensions and tolerances. Electrical-discharge
software package, from which a model of the mold is machining (Section 275) can also be used to make this
automatically generated. The geometric information mold; however, it was determined that the procedure
is sent to the milling machine, and the machining was about twice as expensive as machining the mold
steps are planned. by computer numerical control, and it produced
Next, an offset is added to each surface to molds with lower dimensional accuracy.
account for the nose radius of the end mill during
machining, thus determining the cutter path (i.e., the Source: Courtesy of Mold Threads, Inc.