1. 9/19/2015IENG 475: Computer-Controlled Manufacturing Systems 1 IENG 475 - Lecture 12 Relay and Pneumatic (Fluid) Control Logic

2. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 2 Assignment Begin HW 04. Do this in teams of 1 – 2 persons. Complete Product Design & Cut Personal Parts Finish programming verification & cut individual parts – by end of lab 24 APR. Begin documentation of team project, ASAP. Most of the routing information can be pulled from your MasterCAM files, and you can pull images from the SolidWorks files. Remember to collect timing data as you go!

3. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 3 Relays (Switches) Specification: Poles & Throws Making (N.O.) / Breaking (N.C.) Latching (toggle) / Non-latching (momentary) Transfer between low power logic controls and high power energy controls Coil Nomenclature: “relay”(< 10 A) “power relay”(10 - 30 A) “contactor”(> 30 A) “starters”(Overload protection, thermal) Potential problem: “contact bounce”

4. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 4 Switch Nomenclature Poles – number of individual complete circuits switched at a time Throws – number of positions for each pole Normally Open / Normally Closed – stable position (if there is one) Latching / Momentary – stays in position / returns to normal position Single Pole, Single Throw, Normally Open, Latching Single Pole, Single Throw, Normally Closed, Momentary Double Pole, Single Throw, Normally Open, Latching Double Pole, Single Throw, Normally Open, Momentary Double Pole, Double Throw, Latching NO NC COM Single Pole, Double Throw, Latching NO NC NO NC COM SPST - NO Latching SPST – NC Momentary SPDT – Latching (Toggle) DPST - NO Latching DPST – NO Momentary DPDT – Latching (Toggle)

5. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 5 Wire Logic Review: Current flows from source to ground “AND” (): c = ab “OR” (+): c = a + b “NOT” ( ¯ ): c = a cbac b aca

6. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 6 Wire Logic Example: Missile engine (e) should start only when the President (a) orders it fired and both range officers (b and c) concur with the order. Once fired, the engine should stay on unless the self-destruct (d) is activated. e = [ ( a b c ) + e ] d ba e e dc

7. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 7 Pneumatics Why use Pneumatic Controls? Can withstand stalling without damage Explosion proof Generate little heat (at point of operation) No shock hazard Can operate underwater with minimal problems Can obtain high speeds Can obtain medium sized forces Switching Sense: Normally Not-Passing / Normally Passing Compare with N.O. / N.C. for electrical switching

8. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 8 System View Components of a shop pneumatic system: compressor receiver main line branch line outlet

9. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 9 ISO Symbology Air flow paths are shown as solid lines. Valve ports are shown on the outside of one of the position squares, denoting the normal position. Flow paths within the valves are shown as arrows. Terminations are shown as lines with a short “cap” line perpendicular to the end (T). Exhaust ports are shown as lines terminated with a “outward” pointing triangle.

10. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 10 Signal / Control Valves Signal & Control Valves: Number of ports may be counted from the lines exiting the normal position square Number of squares is the number of positions Example: 3/2 manually actuated signal valve Function is evident by shifting position squares

11. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 11 Valve Actuation General (Manual) Actuation Mechanical Actuation Solenoid Actuation Air Actuation

12. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 12 (OR gate) Shuttle Valve (AND gate) Two Pressure Valve Logic Valves

13. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 13 Dual Acting Cylinder To extend the cylinder, air flows in the left side, exhausting the right side... To retract the cylinder, air enters on the right side, exhausting the left side.

14. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 14 ISO Pneumatic Diagrams From top to bottom, component layers are: Actuators Speed Controls* Control Valves Logic Valves Signal Valves Pressure Supply * not discussed in handout

15. 9/19/2015 IENG 475: Computer-Controlled Manufacturing Systems 15 Questions & Issues Lab: Computer-Aided Milling/3-D Printer/Laser Operations Finish CAD/CAM work Personal design parts (by lab this week, in team folder) Lathe/3-D Print part (at least 1 per team, in team folder) Mill Part (at least 1 per team, in team folder) Laser Engraver (at least 1 per team, in team folder) Drill Part (1 per team, organize with team) Perform CNC Milling & Turning, Engraving, Drilling All parts – timing!