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Unformatted text preview: be obtained by summing all the
individual feeding indices
Feeding ratio = Total relative feeding cost / Number of A
The aim is to minimize this factor and an acceptable limit
FITTING ANALYSIS (FA) : The proposed sequence of
assembly must be known. An assembly flowchart must be
prepared to indicate the order in which each part is
gripped, assembled to its mating components and where Reference : Lucas Engineering and Systems Page 16 of 22 S. Venkannah Factory Automation MECH 3135 necessary fixed in position to produce the completed
FA made up of 3 sections:
Gripping Analysis examines the ease with which each part
can be held for transportation from the point of
presentation within the automatic assembly system to the
stage where insertion is complete.
Each component is examined for its suitability for
gripping and assigned the appropriate gripping index.
Components where handling is straightforward receive a
low gripping index.
Fitting Analysis assesses the relative ease or difficulty of
carrying out each assembly task required to assemble the
complete product from its constituent parts.
Each fitting process is allocated a relative cost index.
Individual index values of ≥ 1.5 infer the presence of a
fitting problem. Reference : Lucas Engineering and Systems Page 17 of 22 S. Venkannah Factory Automation MECH 3135 NON ASSEMBLY ANALYSIS: a relative cost index for
non assembly process is allocated. E.g. of such processes
are welding, adhesive bonding, setting, testing, measuring,
placement into a work holder.
FITTING ASSESSMENT: A total relative cost can be
obtained by summing the individual fitting indices.
Fitting ratio = Gripping costs + Fitting process costs
+ Non assembly costs
Number of parts
The aim is to minimize the above ratio but for an
acceptable design the fitting ratio must generally be <2.5
After product/s have been fully analyzed certain aspects of
the design, component feeding and assembly will be
highlighted as being out of recommended limits.
DESIGN Efficiency: Examine all parts which have been
designated as “B” and try to eliminate them or combine Reference : Lucas Engineering and Systems Page 18 of 22 S. Venkannah Factory Automation MECH 3135 them with an “A” component. May help bring out novel
FEEDING of Components:
While bringing about a design concept to satisfy the
required design efficiency rating, consider suitability of
the component part design for handling and feeding.
Usually simple changes in the design of those parts
presenting feeding problems will eradicate the problems
without compromising the component function.
Components resulting from the redesign must provide
with suitable gripping surfaces.
The product redesign stage must consider the task of
actually assembling the parts into their final position. If
this is done, changes to the component to reduce high
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This document was uploaded on 03/12/2014 for the course MECHANICAL 214 at University of Manchester.
- Spring '14