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Unformatted text preview: utomation MECH 3135 FITTING Analysis: The types of gripping, insertion and
fixing operations required are identified, each operation is
rated and the whole assembly task gets a fitting ratio. The
threshold value is 2.5.
Functional Analysis is carried out in four stages:
Stage 1 : Determine the functional requirements of the
Stage 2: Decide whether the product can be considered as
a whole or as a series of functional sub sections. Best to
consider the product as a whole and avoid duplication of
features in adjacent parts.
Stage 3: Components are divided into 2 categories.
Components A: they carry out functions vital to the
performance of the product e.g. shaft, adjusting screws
Components B: their purposes is not critical to the
product e.g. locators, fasteners Select a major functional element to start the point of the
analysis. Reference : Lucas Engineering and Systems Page 13 of 22 S. Venkannah Factory Automation MECH 3135 Stage 4: Categorise mating components in a logical
progression using the questioning routine in the Functional criteria chart.
Functional Assessment given in terms of a design
E= no. of A components x 100 Total number of components
E must be as high as possible but a threshold of 60% is
1. It may be possible to obtain the required movement
by flexing the component
2. in some cases, the same material may have different
functional properties and therefore must remain a
3. a requirememnt for a different material may be for
insulation, wear resistance, vibration and damping
4. the part and its mating part could be made of the
same material or it may be treated locally to provide
the required property. Reference : Lucas Engineering and Systems Page 14 of 22 S. Venkannah Factory Automation MECH 3135 5. can the part be deformed to give the desired
RULE: Assess what is, not what should be.
• The analysis will help to determine the components
necessary for the functioning of the product (A) and
to highlight the theoretically non essential ones (B). If
there are doubts, make the component “B”
• Parts rated as A may no longer be required in the
• Parts rated as B may still remain in the redesign for
aesthetic or legislative reasons
• Careful when rating screws and springs as all similar
components may not perform the same function.
• There may be good economic reasons for using
separate components when in theory they may be
AUTOMATED FEEDING ANALYSIS:
A feeding ratio is obtained from a three stage analysis: Reference : Lucas Engineering and Systems Page 15 of 22 S. Venkannah Factory Automation MECH 3135 Stage 1 : Determine whether components are best
transported in a retained orientation or from bulk supply
and then re orientated at the input point.
Stage 2: Assess the general physical properties for
automatic feeding of those components that will not be
transported with the retained orientation.
Stage 3 : Examine the suitability of the detailed design of
those components proposed for automatic feeding
A total relative cost can...
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This document was uploaded on 03/12/2014 for the course MECHANICAL 214 at University of Manchester.
- Spring '14