2.008-spring-2004 S.Kim Design & Manufacturing II Spring 2004 Assembly & Joining 1

2.008-spring-2004 S.Kim 2 Dexter ’ s Plastic Can -cool ? -gas leakage ? -recycling?

2.008-spring-2004 S.Kim 3 A 2002 Yo-Yo vs. a free gift

2.008-spring-2004 S.Kim 4 Guidelines to Assembly Design  Minimize parts  Design assembly process in a layered fashion  Consider ease of part handling  Utilize optimum attachment methods  Consider ease of alignment and insertion  Avoid design features that require adjustments

2.008-spring-2004 S.Kim 5 Manufacturing Market Research Conceptual Design Factory, Systems & Enterprise Unit Manufacturing Processes Contributions on the final cost? Welding Bolting Bonding Soldering Machining Injection molding Casting Stamping Chemical vapor deposition Assembly and Joining

2.008-spring-2004 S.Kim 6 Cost of Design Changes J.Chun and realisation/res_int/ipps/dfa1.htm time

2.008-spring-2004 S.Kim 7 Typical Cost Breakdown Selling Price Engineering 14% R&D 5% Admin, sales 24% Manufacturing 38% Manufacturing Costs Plant Machinery 12% Indirect labor 26% Direct labor 12% Parts, Material 50% Profit 19%

2.008-spring-2004 S.Kim 8 Assembly business M. Culpepper Industry % Workers in Assembly Automobile Aircraft Telephone & Telegraph Farm Machinery Home appliances Two-wheel vehicles

2.008-spring-2004 S.Kim 9 Optical Connectors MT connector Alignment errors

2.008-spring-2004 S.Kim 10 Initial Quality Study Problems experienced after 90 days of ownership per 100 vehicles IQS: 0 to 100, 100 to 200, 200 and over

2.008-spring-2004 S.Kim 11 The automobile industry, 1980 ’ s Sullivan, 1986 Problem “fine and fix” (US company) Problem prevention (Japanese company) Product Launch SOP Months Relative to Product Launch Design Changes per Week

2.008-spring-2004 S.Kim 12 Good Design DFMA (Design for Mfg. & Assembly) Simplicity for both human operators and robots Even Kids can do. images/items/ _detail.jpg

2.008-spring-2004 S.Kim 13 DFA guide  Simplicity is the best DFA. Minimize part numbers, operations, simplify assembly sequence (steps) and set-ups  Standardize components, use suppliable common parts  Minimize assembly directions (layered structure) N. Suh Figure 3.3. Can and bottle opener. This bottle/can opener satisfies two FRs: (1) opens cans, and (2) opens bottles. If the requirement is not to perform these two functions simul- taneously, then this physically integrated device satisfies two independent FRs.

2.008-spring-2004 S.Kim 14 DFA guide (cont.)  Modular design, product families, assembly friendiness  Use symmetrical parts  Physical integration  Minimize sharp, delicate, flexible, slippery part  Relax tolerances on non-critical locations.  Approachable, line of sight Size Fragile/Sharp Slippery/Flexible Symmetry

2.008-spring-2004 S.Kim 15 DFA Guide (cont.)  Material for DFA, avoid flexible components  Concurrent engineering  Design for disassembly (recycling, repair, retrofit)

2.008-spring-2004 S.Kim 16 DFMA  Hitachi assemblability evaluation method  Lucas DFA  Boothroyd-Dewhurst DFA (BD)

2.008-spring-2004 S.Kim 17 Design for Assembly Number of parts

2.008-spring-2004 S.Kim 18 Pneumatic Piston Sub-Assembly T. Gutowski screw spring piston cover piston stop main block Redesigned 1 – snap on cover and stop (plastic) 2 – spring(steel) 3 – piston (aluminum) 4 – main block (plastic)

2.008-spring-2004 S.Kim 19 DFA: Examples Pa rt ca n jam when Tape ring the hol e inserted into hole. facilitates part insertion. Alignment

2.008-spring-2004 S.Kim 20 DFA for Automation: Examples Parts are difficult Chamfers assist to assemble. assem bly. Parts are difficult Changing part geometry to align properly; allows it to be aligned properly jamming can occur. before it is released. Kalpakjian, Benhabib

2.008-spring-2004 S.Kim 21 Assembly automation Challenges  Parts Feeding Sorting Orienting  Pick-and-place  Assembly PCB assembly?

2.008-spring-2004 S.Kim 22 Non-vibratory Feeding Groove Hopper Rotation axis Rotary mechanism with multiple blades Inclined discharge rail B. Benhabib

2.008-spring-2004 S.Kim 23 Vibratory Parts Feeding B. Benhabib Track Bowl Electromagnet Outlet Leaf springs Base Translational vibration Torsional vibration

Vibratory Feeding -orientation Second attachment (rejects c and d ) First attachment (rejects a and b ) Third attachment (orients e and f ) Side view Top view Discharge hole B. Benhabib spring-2004 S.Kim 24

2.008-spring-2004 S.Kim 25 Magnetic Parts Feeding Parts picked up by magnets Delivery chute Magnets Parts Stationary hopper

DFA for Transporting Flat ends prevent jamming. Non-functional peg prevents jamming. Wider edge surface prevents overlap. B. Benhabib spring-2004 S.Kim 26

2.008-spring-2004 S.Kim 27 Automated Assembly Transfer  Transfer lines  Conveyor  Automated Guided Vehicle Positioner Assembly Operations

2.008-spring-2004 S.Kim 28 Transfer Lines Piston Stop Work carriers Fixed rail Step Transfer rail Slide

2.008-spring-2004 S.Kim 29 Rotary Assembly Transfer B. Benhabib Positioning unit Riveter Adhesive-bond applicator Inspection station Completed pieces Vibratory bowl Feedtrack

2.008-spring-2004 S.Kim 30 AGV Pallet load / unload mechanism Workpiece Pallet Safeguards against collision

2.008-spring-2004 S.Kim 31 Pick & Place Positioner Linear actuator Rotary actuator Gripper Fixed-length arm Rotary actuator Fixed base

Shoulder swivel Robot Hydraulic/electric power unit Elbow extension Arm Robot controller Arm sweep Pitch Yaw Wrist spring-2004 S.Kim 32

2.008-spring-2004 S.Kim 33 Robots: Components  Manipulator  positioning  power  stiffness  control  End effector  tooling

2.008-spring-2004 S.Kim 34 Robots: Applications  3 D’s (Dull, Dirty, Dangerous)  3 H’s (Hot, Heavy, Hazardous)  Materials handling  Spray painting  Spot welding  Arc welding  Assembly J. Chun

2.008-spring-2004 S.Kim 35 Good Design Principles: DFM Assembly  Design parts to be self-locating and self-aligning  Error-proof parts to make incorrect assembly impossible  Minimize the number of parts.  Minimize the number and variety tools for assembly  Minimize the number of axes of insertion  Ensure clear vision and access for all assembly operations  Minimize the number and complexity of adjustments  Eliminate the need to hold down, clamp or fixture parts  Eliminate special assembly tools Alignment

2.008-spring-2004 S.Kim 36 What assembly process to choose?  Reasons to avoid assembly  Reasons that justify assembly

2.008-spring-2004 S.Kim 37 Workholding  Immobilization of a workpiece for machining or assembly  Jigs: locating and holding workpiece, guiding tools  Fixtures: locating and holding  Provide maximum accuracy and ease of mounting  Datum

3-2-1 rule of locating  6 dof, (D x,D y,D z ) and (R x,R y,R z )  3 support Points (1, 2 and 3) eliminate (R x and R y ) and (-D z ); 2 points (4 and 5) eliminate (R z ) and (- D x ); and, 1 point (6) eliminates (-D y ).  Push or clamp 3 directions, x,y,z. Direction of resultant clamping force B. Benhabib spring-2004 S.Kim 38