Transcript Slide 1

Re-engineering of current products to ease assembly and
integrate Design for Manufacturing and Assembly within the
design process
A Knowledge Transfer Partnership between the
University of Plymouth
And
Rittal – CSM Limited
Rajesh Radhakrishnan
Company Profile
• Rittal CSM is a part of Friedhelm Loh Group
• Rittal International is the world’s largest manufacturer of data
communication and industrial enclosures
• Rittal CSM celebrating 25th year in Plymouth
• Products are classified into OEM and Non OEM
Business Driving factors
• High Quality
• Quicker to Market
• Low Cost
Rittal has started concentrating on
Cost and Time Reduction.
Lean Design Practise
DFMA
Introduction to my KTP project
KTP Project
Redesign the current
products considering
DFMA
Cost Saving
Reduce the
Assembly Time
Implement DFMA within
the design process
Designers
Exposed to DFMA
Cost Saving in
Future Projects
Improved
Manufacturability
and Assembly
DFMA Design Proposals
Snap fit Lock Rod Block
Present Component
Cost Saving / Rack
Cost Saving/ Year
£0.43
£25,800
Cost Saving / Rack
Annual Cost saving
£ 1.28
£ 76,800
New design
Side Panel Fixing
Depth bracket
Universal weld bracket
Tail Bar
Cost Saving / Rack £ 0.575
Annual Cost Saving £ 34,500
DFMA Design Proposals
DFMA design top canopy
with tool-less fixings
Simplified new of
rear door assembly
Tool-less snap fit
logo batch
New castor wheels
Cost Saving / Rack £ 21.80
Annual Cost Saving £ 104,640
New castor bracket with
reduced fixings
Implementing DFMA within the Design practise
• Detail study was done on various DFMA techniques such as Boothroyd Dewhurst,
Lucas and Lean Design.
•Analysed the work culture of the design department.
•Formulated a DFMA tool
•All the designers were trained on the new tool
•DFMA was integrated to the RFEA (Request for Engineering Assistance) system on
27/07/09
Part reduction for Simplified Design
Standardisation of parts
Consideration of Fasteners and Joints
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2.
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2.
Understanding the application.
Evaluate each part,
a. Can be eliminated?
b. Combined with others?
c. The function can be performed
in other ways?
Questions for Part reduction
2.
3.
Standardisation by using common parts, processes and
materials across all models and other product lines.
Minimise unique or customised components.
Use PDM, CSM, material catalogs and approved part lists
for standardisation of components.
PDM - Product Data Management systems
CSM- Component Supplier Management systems
•Does the part have a relative motion with
other parts?
•Does the part need to be of a different
material?
•Is the part required for assembly or access?
3.
4.
Use standardised fasteners and minimise variety.
Use integral attachments like snap fit, Interference fit,
integral hinges, self jigging subcomponents, plastic
part locking etc.
Consideration of tool less and plastic fasteners.
Consider the material, product functional
requirements, assembly and service before selecting
the fastening technique.
Design for part handling and self securing
Designing or Re – Designing
of component
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2.
3.
4.
Component Design for error free
Assembly
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5.
Design components with verifiability eg:
go/no go, stopping points, using notches,
asymmetrical holes, stops etc.
Avoid the need for assembly to make
decisions and manual adjustments.
Control the features in a product which are
prone to error.
Use colour codes for the parts which look
alike but have a different application.
Provide inexpensive inspection at the end
each process.
Design for Fabrication and Processes capability
Add features to parts which aid in self securing.
Design end to end and rotationally symmetrical
parts.
Design parts that are easy to grab and fix.
Avoid sharp edges, excess flexibility, heavy
parts etc.
Design for ease of assembly
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Eliminate unnecessary part features.
Avoid unnecessarily tight tolerances.
Design components for improved reliability by controlling the
noise factors (considered in the concept phase)
Design components with simple shapes and avoid machining.
Choose cost effective fabrication techniques eg: castings,
stamping etc.
Use features with standard dimensions in the design.
Avoid undercuts, thin wall or webs, counters, deep pockets etc.
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3.
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Avoid or minimise the need for part
orientation during assembly.
Avoid the need for measuring gauges.
Ensure accessibility, visibility and never bury
the important components.
Provide chamfers and tapers.
Take advantage of aid of gravitational forces.
Avoid using temporary fasteners
Noise Factors - Factors beyond the designer’s control but affecting the design
eg: transportation, improper loading and unloading etc.
Design and Development Engineer – R.R
Integration of DFMA in RFEA
When a design document is updated by a designer RFEA prompts for a DFMA check
When DFMA is not appropriate, the reason is documented
Integration of DFMA in RFEA
When DFMA is performed
DFMA Design guidelines
Click the drop down box in the DFMA design principles and select the appropriate design guidelines and
type in the description of the design change
Major highlights of the system
• Design Documents cannot be uploaded without considering a DFMA check.
• Minimum of 4 DFMA design principles have to be considered.
• DFMA design checks are automatically documented for future reference.
• DFMA status can be viewed in the RFEA table with the designer’s updates (can be used for
DFMA performance review)
Benefits form the KTP Project
Company
• Potential cost savings based on DFMA identified
• Tool less fastener selection library was formulated
• Reduced assembly and manufacturing complexity
• Product simplification
• Improved product quality and reliability
• Increased manual assembly efficiency
• Reduced assembly costs
University
• Presentation given MSc Mechanical Engineering students
• Writing a case study on the implementation of a lean design tool
• DFMA design tool can be used by students
Associate
• Real time design and manufacturing experience
• Good exposure to DFMA and Lean product design
• Gained good knowledge in tool less fastening system