MECH152-L25 - 1 Tool Design MECH152-L25 - 2 Types of Tools • • • • • • • Material Cutting Tools Workholding Devices Pressworking Tools Bending, Forming and Drawing Dies http://www.youtube.com/watch?v=gkHbRVUvFgw&feature=channel_page Tool Design for Inspection and Gaging Tool Design for Joining Process Tooling for Casting http://www.youtube.com/watch?v=z4D76vMqwD4&feature=channel_page http://www.youtube.com/watch?v=3ciyG_hidhE&feature=channel_page http://www.youtube.com/watch?v=4Pw_tcgIiTQ&feature=channel_page MECH152-L25 - 3 General Considerations • • • • • • • Safety and Ergonomics Tool Materials Heat Treatment Surface Roughness and Finish Tolerances and Fits Tooling Economics Material Handling MECH152-L25 - 4 Safety and Ergonomics (I) • Safety should be built into the design with due respect to legal requirements • Sufficient clamping and rigidity of the tool design is necessary • Guards should be introduced to movable parts of the machine • Limit switches to protect workers and product against moving parts • Electrical equipment should be properly grounded MECH152-L25 - 5 Safety and Ergonomics (II) • Exhaust system for air polluting system • All adjustments and clamping should be easily accessible • Quick release or emergency braking mechanism may be needed for special cases • Prevent severe burns or eye injury for welding or thermal process • Provision for handling pressurized and toxic equipment MECH152-L25 - 6 Tool Materials (I) • Tool steels (principal materials) – Tool and Die Steel (typical hardness RC40~60) • • • • • • • • • • W, Water-Hardening Tool-Steels O, Oil-Hardening Tool-Steels A, Air-Hardening Medium Alloy Die-Steels D, High-Carbon High-Chromium Die Steels S, Shock-Resisting Tool-Steels H, Hot-Work Die Steels P, Low-Carbon Mold Steels T and M, Tungsten and Molydenum High-Speed Steels L, Low-Alloy Tool-Steels F, Carbon-Tungsten Finishing Steels (http://www.efunda.com/materials/alloys/tool_steels/tool.cfm) • Cast Iron • Stainless Steel MECH152-L25 - 7 Tool Materials (II) • Non-ferrous materials - limited productions only (Aluminum, Magnesium, Zinc, Lead, Beryllium, Bismuth) • Composite materials – soft tools for limited run MECH152-L25 - 8 Workholding Devices Workholding Devices – All devices that hold, grip, or chuck a workpiece in a prescribed manner of firmness and location, to perform on it a manufacturing operation. MECH152-L25 - 9 Fixture & Jig Fixture: - Hold and accurately position a workpiece http://www.youtube.com/watch?v=ujKyRrf-Z1M&feature=channel_page Jig: - Also be used to hold and position a workpiece. - Provides some means for guiding the cutting tool http://www.youtube.com/watch?v=2ikkuZe0zQU&feature=channel_page MECH152-L25 - 10 Examples - I • High Rise Clamps http://www.carrlane.com/Catalog/index.cfm High-Rise Clamps can be stacked on Narrow Riser Blocks and Spacer Blocks to reach tall workpieces MECH152-L25 - 11 Examples II http://www.steelsmith.com/ • Swing Clamp Please refer to the price list also! ARM: MODULAR IRON PER ASTM A536 GRADE 65-45-12, ZINC PLATED CLEAR CHROMATE ALL OTHER PARTS: MILD STEEL, BLACK OXIDE FINISH MECH152-L25 - 12 Examples III Automatic Reversible Cam Action Workholding Assemblies http://www.youtube.com/watch?v=vrrjLYn-6WY Methods of Location 3-2-1 Principle MECH152-L25 - 13 http://www.youtube.com/watch?v=wTs_IaD0JWU&feature=PlayList&p=3AFB507B668AF162&index=35 - A workpiece will be completely confined when banked against: - 3 points in one plane 2 points in another plane 1 point in a third plane If the planes are perpendicular to each other - Buttons should be as far apart as possible - Greater spread, Less alignment error MECH152-L25 - 14 Methods of Location I 12 degrees of freedom 3 pins arrest 5 dof MECH152-L25 - 15 Methods of Location II 5 pins arrest 8 dof Horizontal workpiece 6 pins arrest 9 dof Vertical workpiece MECH152-L25 - 16 Methods of Location III Radical location with internal pins or plug Radical location by external pins MECH152-L25 - 17 Methods of Location IV 7 dof arrested by V locator with stop pin Workholder with multiple V locators MECH152-L25 - 18 Tool Forces I Pin-type drill fixture resisting torque and thrust Tapping fixture resisting torque and thrust MECH152-L25 - 19 Tool Forces II Workholder for broaching operation Cutting Forces resisted by solid jaw of vise Cutting force resisted only by friction MECH152-L25 - 20 Tool Forces III Mechanical methods of transmitting and multiplying force (A) Screw (B) Cam (C) Wedge (D) Toggle link (E) Lever (F) Combined screw and wedge MECH152-L25 - 21 Clamping Forces I Fixture components MECH152-L25 - 22 Clamping and Support http://www.youtube.com/watch?v=l-V4mplHjZ8 Clamping and support of large workpiece MECH152-L25 - 23 Fixture Components MECH152-L25 - 24 Fixture Components Toggle clamp http://www.youtube.com/watch?v=H4r8hUyZMUY http://www.youtube.com/watch?v=ZefYGTMKRUw http://www.youtube.com/watch?v=nheuik2YHkI Quick-acting screw Jigs and Fixture Design Principles MECH152-L25 - 25 • Review the workpiece to determine the manufacturing processes • Decide on the number of setups • Determine for each setup – Reference surface – Workpiece location – Workpiece clamping and rigidity – Ergonomics and safety http://www.youtube.com/watch?v=ujKyRrf-Z1M&feature=channel Fixture for Rectangular Components MECH152-L25 - 26 Clamping action • Location and holding for flat surface • Base plate - reference surface for setup • Clamp – quick action cam-based clamp Fixture for Rectangular Components MECH152-L25 - 27 • Hydraulic clamp for larger clamping force • Swing clamp http://www.youtube.com/watch?v=1RMqoQlZ-2c http://www.youtube.com/watch?v=jkAINXgZaCk Fixture for Rectangular Components MECH152-L25 - 28 Magnetic chuck http://www.youtube.com/watch?v=WzawhEUBLL8&feature=PlayList&p=CAC636741CCDCCB0&playnext=1&playnext_from=PL&index=4 http://www.youtube.com/watch?v=S-xKCAHpU-4&feature=PlayList&p=CAC636741CCDCCB0&playnext=1&playnext_from=PL&index=6 http://www.youtube.com/watch?v=8pabjZp4D2Y Vacuum chuck http://www.youtube.com/watch?v=xr3lfAvQuJs&feature=related http://www.youtube.com/watch?v=2jcQZ5W4ED4 Fixture for Rectangular Components MECH152-L25 - 29 Electrostatic chuck Vacuum chuck Fixture for Circular Components Round workpiece held with strap clamp and T bolts Fixture for straddle milling connecting rod MECH152-L25 - 30 Fixture for Circular Components MECH152-L25 - 31 Workpiece held in a 4jaw chuck for a boring operation http://www.youtube.com/watch?v=npJfKhkS0QE Nut arbor Fixture for Circular Components V block MECH152-L25 - 32 Drill jig – V block, quickacting clamp, and drill bushing combination http://www.youtube.com/watch?v=QFH2kUorn88 Fixture for Circular Components MECH152-L25 - 33 Internal and endwise chucking Between centers and combination with chucking Fixture for Circular Components Solid mandrel MECH152-L25 - 34 Roll lock type expanding mandrel Fixture for Circular Components Split busing and split collet MECH152-L25 - 35 Axial location by collet Collet with stopper http://www.youtube.com/watch?v=bJIIeN4rg3E Fixture for Circular Components MECH152-L25 - 36 Collet with immediate bushing to eliminate axial shift Collet for internal chucking MECH152-L25 - 37 Rigid and Elastic Workholding Rigid workholding Elastic and spring workholding Rigid/hydraulic workholding MECH152-L25 - 38 Accuracy of Work Location Accuracy of work location Concentricity of workpiece by collet Workholders for Irregular Workpiece MECH152-L25 - 39 Pump-type jigs MECH152-L25 - 40 Workholding Selection Workpiece rotation Tool rotation MECH152-L25 - 41 Workholding Selection Steady to reduce workpiece vibration Minimizing cutting force by applying holding force close to point of tool application http://www.youtube.com/watch?v=2o74aR0JL1k MECH152-L25 - 42 Cutter Setup MECH152-L25 - 43 Box-Type Drill Jigs MECH152-L25 - 44 Milling Fixture MECH152-L25 - 45 Milling Fixture MECH152-L25 - 46 Milling Fixture Indexing fixture http://www.youtube.com/watch?v=JkftVHaMQSs Key slot milling MECH152-L25 - 47 Milling Fixture