Copyright 1997 Society of Manufacturing Engineers FUNDAMENTAL MANUFACTURING PROCESSES SHEET METAL SHEARING AND BENDING

Transcription

1 FUNDAMENTAL MANUFACTURING PROCESSES SHEET METAL SHEARING AND BENDING SCENE 1. CG: FBI warning SCENE 2. CG: disclaimer Always read the operating manual and safety information provided by the manufacturer before operating any shearing or bending equipment. Make sure all machine guards are in place, and follow all safety procedures when working with or near shearing or bending equipment. SCENE 3. tape 40, 01:00:00-01:00:12 ANI: SME logo SCENE 4. tape 25, 01:01:06-01:01:20 series opening title: FUNDAMENTAL MANUFACTURING PROCESSES tape 63, 12:06:32-12:09:06 opening music MUSIC UP AND UNDER THE FUNDAMENTAL MANUFACTURING PROCESSES VIDEO SERIES, EXAMINING THE TOOLS AND TECHNIQUES OF PRECISION MANUFACTURING. SCENE 5. program title: CG: SHEET METAL SHEARING AND BENDING white text centered on black SCENE 6. tape 250, 02:04:58-02:05:05 sheet stock being sheared tape 356, 00:13:53-00:14:03 sheet stock being bent THIS PROGRAM EXPLORES THE BASICS OF SHEET METAL SHEARING AND BENDING. TWO OF THE OLDEST AND MOST BASIC OPERATIONS IN ALL OF METALWORKING ARE SHEARING..., AND BENDING. SCENE 7. tape 249, 01:08:30-01:08:41 sheet stock being sheared tape 249, 01:17:18-01:17:29 close up on blades showing the cutting of metal SHEARING IS THE MECHANICALMECHANICAL CUTTING OF SHEET METAL BY MEANS OF TWO OPPOSING BLADES. IT IS USED TO CUT LARGE SHEETS OF MATERIAL INTO SMALLER,

2 MORE MANAGEABLE SECTIONS, TO BE USED IN LATER OPERATIONS. SCENE 8. tape 289, 01:06:47-01:07:00 shearing action on press SHEARING IS ALSO UTILIZED TO CUT SHEET METAL STOCK AROUND THE COMPLETE PERIMETER OF A SHAPE TO FORM A WORKPIECE KNOWN AS A BLANK.. OR SLUG. SCENE 9. tape 289, 01:10:47-01:10:58 additional forming operation performed on blank THESE WORKPIECES ARE THEN USED IN OPERATIONS SUCH AS FORMING, PUNCHING AND TRIMMING TO COMPLETE THE PART. --- FTB --- SCENE 10. tape 250, 02:16:39-02:16:47 bending operation BENDING IS THE CREATION OF THREE-DIMENSIONAL SHAPES OUT OF TWO-DIMENSIONAL MATERIAL. SCENE 11. tape 350, 15:02:42-15:02:52 c.u. bending with thin stock BENDING IS A FAST, ECONOMICAL WAY TO PRODUCE AN ENDLESS VARIETY OF PARTS FROM SHEET METAL AND PLATE, OFTEN WITHOUT THE NEED FOR SECONDARY FORMING OPERATIONS. --- FTB --- SCENE 12. CG: SHEET METAL SHEARING white text centered on black SCENE 13. tape 249, 01:10:42-01:10:59 c.u. part being sheared tape 251, 03:05:11-03:05:18 ordinary hand shears cutting stock IN MOST SHEARING OPERATIONS, THE EDGES OF TWO KNIVES -A FIXED LOWER BLADE, AND A VERTICALLY MOVING UPPER BLADE MEET PROGRESSIVELY FROM ONE

3 SIDE OF THE WORKPIECE TO THE OTHER TO SHEAR THE MATERIAL, LIKE ORDINARY HAND SHEARS. SCENE 14. tape 339, 03:00:50-03:01:10 ANI: c.u. upper and lower blades tape 339, 03:01:50-03:02:10 ANI: yellow rake lines appear showing rake angle CG, SUPER: BLADE RAKE/SHEAR ANGLE THE ANGLE AT WHICH THE UPPER AND LOWER BLADES ARE ALIGNED WITH EACH OTHER IS CALLED THE BLADE RAKE OR SHEAR ANGLE. SCENE 15. tape 345, 01:00:59-01:01:07 ANI: side view of shearing process, arrows appear to show clearance, freeze last frame CG, SUPER: BLADE/KNIFE CLEARANCE THE DISTANCE BETWEEN THE UPPER AND LOWER BLADES IS KNOWN AS THE BLADE OR KNIFE CLEARANCE." KNIFE CLEARANCE IS ESSENTIAL FOR PROPER SHEARING, AND IS MODIFIED FOR DIFFERENT MATERIAL THICKNESSES AND STRENGTHS. SCENE 16. tape 345, 01:01:26-01:01:50 ANI: same animation, blades coming together, penetrating the material until a crack or tear develops from both sides of the material, part separated AS THE BLADES COME TOGETHER AND CONTACT THE WORKPIECE, THEY PARTIALLY PENETRATE THE MATERIAL. THIS BUILDS UP OPPOSING FORCES IN THE STOCK. A CRACK OR TEAR--CALLED THE SLIP PLANE THEN DEVELOPS ON BOTH SIDES OF THE MATERIAL, SEPARATING THE STOCK. SCENE 17. tape 328, 06:06:24:00 freeze of graphic, dissolve into animation tape 328, 06:06:26-06:06:40 ANI: photomicrography of die-cut edge, arrow indicates burnished edge where the punch penetrated, then indicates the rough edge where fracture occurred SCENE 18. tape 345, 01:02:11-01:02:19 ANI: knife blades before shearing, yellow lines indicate THE SHEAR BLADES TYPICALLY PENETRATE THE STOCK NO MORE THAN ONE THIRD OF THE STOCK THICKNESS BEFORE THE SLIP PLANE OCCURS. THE EXACT AMOUNT OF PENETRATION VARIES WITH MATERIAL HARDNESS AND KNIFE CLEARANCE. ON MOST SHEARS THE UPPER KNIFE IS ALIGNED AT AN

4 the angle of upper blade alignment to lower blade, freeze last frame SCENE 19. tape 345, 01:02:35-01:03:05 ANI: continue previous animation, upper blade contacting stock, indicate concentrated shearing force, fracture along straight line parallel to the surface the knives SCENE 20. ANI: continue previous animation, upper blade continuing through stock, moving away from lower blade, workpiece dropping away ANGLE TO THE LOWER BLADE OF BETWEEN ONE-HALF AND TWO-AND-A-HALF DEGREES. THIS ANGLE HELPS CONCENTRATE THE SHEARING FORCE IN THE EXACT AREA OF BLADE ENGAGEMENT BETWEEN THE TWO KNIVES, AND STARTS THE FRACTURE ON A STRAIGHT LINE PARALLEL TO THE SURFACE THE KNIVES. THIS INCLINATION ALSO CAUSES THE UPPER KNIFE TO MOVE AWAY FROM THE LOWER KNIFE DURING THE SHEAR. THISIT INSURES THAT THE SHEARED WORKPIECE--CALLED THE DROP --WILL NOT BECOME WEDGED BETWEEN THE TWO BLADES. --- FTB --- SCENE 21. tape 302, 04:02:05-04:02:20 stock being sheared using stamping die tape 249, 01:01:45-01:01:53 shearing on shearing machine SHEET METAL SHEARING CAN BE DONE WITHIN A SHEARING DIE IN ON A STAMPING PRESS, BUT IS MOST OFTEN PERFORMED USING A MACHINE CALLED A SHEAR. SCENE 22. continue previous shot tape 249, 01:07:01-01:07:18 wide, lower blade affixed to bed, zoom in to upper blade attached to crosshead, shearing CG, SUPER: TABLE/BED CROSSHEAD tape 326, 01:06:58-01:07:04 wide, side of shear CG, SUPER: ENDFRAME tape 249, 01:05:20-01:05:33 c.u. hold-down feet securing stock during shear CG, SUPER: HOLD-DOWN FEET A TYPICAL SHEAR CONSISTS OF A FIXED LOWER BLADE MOUNTED ON THE TABLE OR BED OF THE MACHINE..., AND AN UPPER BLADE SECURED ONTO A VERTICALLY MOVABLE CROSSHEAD. OTHER SHEAR ELEMENTS INCLUDE: THE HOUSING OR ENDFRAME..., AND THE HOLD-DOWN FEET, WHICH SECURE THE SHEET METAL OR PLATE STOCK TO THE TABLE TO PREVENT

5 MOVEMENT DURING THE SHEARING OPERATION. SCENE 23. tape 362, 01:05:55-01:05:58 pan of still, gapless shear tape 362, 01:07:23-01:07:27 pan of still, gapless shear tape 327, 04:03:13-04:03:19 manual shearing operation tape 328, 06:02:00-06:03:00 blue background CG, SUPER: MANUALLY MECHANICALLY HYDRAULICALLY PNEUMATICALLY tape 362, 03:00:40-03:00:50 still of gap shear tape 362, 02:01:40-02:01:50 still of gapless shear tape 362, 01:09:36-01:09:39 still of cnc shear tape 362, 02:01:10-02:01:20 still of cnc shear tape 328, 06:02:00-06:03:00 blue background CG: GAPLESS SHEARS GAP SHEARS RIGHT-ANGLE SHEARS CNC SHEARS IRONWORKERS SHEARS ARE MADE IN A WIDE VARIETY OF SIZES AND STYLES. THEY CAN BE CLASSIFIED BY THE WAY THE CROSSHEAD IS POWERED, EITHER MANUALLY..., MECHANICALLY..., HYDRAULICALLY..., OR PNEUMATICALLY. OR SHEARS CAN BE CLASSIFIED BY THE TYPE OF WORK THEY WERE DESIGNED TO PERFORM. THE MOST COMMON SHEAR DESIGNS INCLUDE: GAPLESS SHEARS, GAP SHEARS, RIGHT-ANGLE SHEARS, CNC OR COMPUTER NUMERICAL CONTROL SHEARS, AND IRONWORKERS. SCENE 24. CG, SUPER: GAPLESS SHEARS tape 326, 01:05:29-01:05:39 med, gapless shears cutting blanks GAPLESS SHEARS HAVE SIDE FRAMES WHICH SUPPORT THE POWER UNIT, AND ARE JOINED TOGETHER BY THE BED AND CROSSHEAD. SCENE 25. CG, SUPER: GAP SHEARS tape 362, 03:01:10-03:01:20 still of gap shear tape 362, 03:02:30-03:02:42 pull out from gap on still of gap frame shear GAP SHEARS ARE USED FOR SQUARING SHEET STOCK AND PRODUCING BLANKS. BECAUSE OF THE GAP, OR THROAT OPENING IN THE SIDES OF THE FRAME, THEY CAN HANDLE LARGER SHEET LENGTHS THAN A GAPLESS SHEAR. SCENE 26. CG, SUPER: RIGHT-ANGLE SHEARS tape 360, 01:04:12-01:04:21 4 shots, right angle shears RIGHT-ANGLE SHEARS EMPLOY TWO SETS OF DUAL BLADES

6 operating within a punch press SET AT A RIGHT ANGLE FOR SIMULTANEOUS CUTS ALONG TWO AXES. SCENE 27. CG, SUPER: CNC SHEARS tape 249, 01:02:35-01:02:50 med, cnc shearing machine, plate stock being moved around by machine COMPUTER NUMERICAL CONTROL OR CNC SHEARS CAN BE PROGRAMMED TO SHEAR A VARIETY OF LENGTHS FROM A SINGLE SHEET. THE SHEET IS AUTOMATICALLY REPOSITIONED IN THE SHEAR FOR EACH CUT. SCENE 28. CG, SUPER: IRONWORKERS tape 328, 05:14:28-05:14:38 ironworker shearing plate tape 328, 05:12:34-05:12:39 ironworker shearing angle iron tape 328, 05:15:11-05:15:16 ironworker shearing bar stock tape 328, 05:10:53-05:10:59 ironworker notching plate tape 328, 05:07:27-05:07:32 ironworker punching plate IRONWORKERS PERFORM SHEARING OF PLATE, STRUCTURAL SHAPES, AND BAR STOCK, AS WELL AS SEVERAL OTHER OPERATIONS INCLUDING NOTCHING, AND PUNCHING. --- FTB ---, AND FORMING. THESE OPERATIONS CAN BE PERFORMED EITHER SIMULTANEOUSLY OR SEPARATELY. SCENE 29. tape 249, 01:11:52-01:12:05 c.u. gage and sensor on a shear, part sheared, another set up tape 328, 06:02:00-06:03:00 blue background CG: BACK GAGING FRONT GAGING SQUARING ARM GAGING PROGRAMMABLE GAGING SHEARS MUST HAVE SOME KIND OF GAGE FOR MEASURING THE PART TO BE SHEARED. FOUR PRIMARY METHODS OF GAGING INCLUDE: BACK GAGING, FRONT GAGING, SQUARING ARM GAGING, AND PROGRAMMABLE GAGING THAT CAN OPERATE UNDER COMPUTER NUMERICAL CONTROL.PROGRAMMABLE GAGING. SCENE 30. CG, SUPER: BACK GAGING tape 249, 01:14:49-01:15:02

7 c.u. workpiece coming into contact with the back gage, part sheared IN BACK GAGING, THE OPERATOR PUSHES THE MATERIAL BETWEEN THE KNIVES UNTIL IT COMES TO REST AGAINST AN ADJUSTABLE STOP, OR BACK GAGE. THE MATERIAL IS THEN SHEARED. SCENE 31. tape 250, 02:11:09-02:11:20 shear cutting stock as it is placed against back gage FOR RAPID, ACCURATE CUTTING, ELECTRONIC SENSORS IN THE BACK GAGE AUTOMATICALLY START THE SHEARING PROCESS ONLY WHEN THE STOCK IS IN THE CORRECT POSITION. SCENE 32. tape 326, 01:02:27-01:02:44 workers placing large sheet in shear, shearing sections tape 250, 02:02:12-02:02:26 support arms holding work until it is cut WHEN THE BACK GAGE IS USED TO SHEAR WIDE DROPS OF THIN METAL, THE MATERIAL OFTEN SAGS, CAUSING AN INACCURATE MEASUREMENT. TO ELIMINATE THIS PROBLEM, A SHEET SUPPORT SYSTEM CAN BE ADDED TO THE BACK OF A SHEAR. GENERALLY, A SHEET SUPPORT HOLDS THE WORKPIECE IN A HORIZONTAL PLANE UNTIL IT IS CUT. THE SUPPORT THEN PIVOTS DOWN, PERMITTING THE WORKPIECE TO DROP. SCENE 33. CG, SUPER: FRONT GAGING tape 249, 01:04:46-01:05:00 med, machine with front gages located in support arms, shearing material IN FRONT GAGING, THE SHEET IS LOCATED WITH RESPECT TO THE CUTTING EDGE BY MEANS OF ADJUSTABLE STOPS OR GAGES LOCATED IN THE TABLE OR FRONT SUPPORT ARMS. SCENE 34. tape 249, 01:21:21-01:21:38 CG, SUPER: SQUARING ARM GAGING med, arm on the end of the shear SQUARING ARM GAGING, WITH THE SQUARING ARM MOUNTED ON THE END OF THE SHEAR, ENABLES THE OPERATOR TO SHEAR A NINETY-DEGREE CORNER ON THE MATERIAL. THE SQUARING ARM CAN BE MOUNTED ON EITHER END OF THE

8 SHEAR TO DISTRIBUTE WEAR ON THE KNIVES. SCENE 35. tape 249, 01:20:12-01:20:24 CG, SUPER: PROGRAMMABLE GAGING the gaging on highly automated cnc shearing machine PROGRAMMABLE GAGING IS HIGHLY ACCURATE, AND IS INCORPORATED INTO MOST CNC SHEARING PROGRAMS. --- FTB --- SCENE 36. tape 249, 01:22:54-01:23:03 c.u knife used in shearing SHARPNESS OF THE KNIFE PLAYS AN IMPORTANT ROLE IN THE EDGE QUALITY OF THE PART. SCENE 37. tape 345, 01:03:23-01:03:33 ANI: upper blade contacting stock, indicate concentrated shearing force, fracture beginning along straight line parallel to the surface the knives A SHARP SHEARING KNIFE CAN CUT TOUGH MATERIALS ALLOYS AS HARD AS ITSELF BECAUSE THE SHARP EDGE CONCENTRATES THE SHEARING FORCE IN A VERY SMALL AREA OF THE WORKPIECE. SCENE 38. tape 345, 01:03:53-01:04:02 ANI: dull upper blade contacting stock, shearing force dispersed over larger area, fracture beginning along straight line parallel to the surface the knives later in shear DULL SHEARING KNIFE EDGES DEFORM THE METAL SURFACE MORE THAN SHARP EDGES SINCE THE SHEARING STRESSES ARE SPREAD OUT OVER A LARGER AREA. SCENE 39. tape 251, 04:33:22-04:33:31 pan of sheared edge tape 328, 06:02:00-06:03:00 blue background CG: CAMBER BOW TWIST IN ADDITION TO THE SHEARED EDGE, THERE ARE THREE INDICATORS OF THE QUALITY OF THE SHEARED PART. THESE INDICATORS ARE THE CAMBER, BOW, AND TWIST THAT REMAIN IN THE PART AFTER SHEARING. SCENE 40. CG, SUPER: CAMBER tape 339, 04:00:40-04:00:50 ANI: part with camber tape 339, 04:01:40-04:01:50 ANI: line appears showing CAMBER IS THE DEVIATION OF THE FLAT DROP S SIDE EDGE FROM A STRAIGHT LINE. CAMBER CANNOT BE

9 straight edge tape 250, 02:05:31-02:05:39 c.u. shearing of part SCENE 41. CG, SUPER: BOWING tape 339, 04:02:10-04:02:20 ANI: bowed part tape 339, 04:02:40-04:02:50 ANI: lines showing bowed part on top of flat surface tape 251, 04:08:16-04:08:24 pan of bowed part SCENE 42. tape 326, 01:08:23-01:08:38 wide pieces being sheared ELIMINATED, BUT IT CAN OFTEN BE REDUCED BY LOWERING THE RAKE ANGLE OF THE UPPER KNIFE. BOWING IS THE TENDENCY OF THE SHEARED PART TO ARCH IN THE CENTER. THIS FREQUENTLY OCCURS WHEN NARROW STRIPS ARE BEING CUT. BOWING IS ALMOST DIRECTLY PROPORTIONAL TO THE RAKE ANGLE OF THE UPPER KNIFE. THE BOW, HOWEVER, DECREASES AS THE WIDTH OF THE DROP INCREASES. IT BECOMES NEGLIGIBLE IF THE DROP IS WIDER THAN FOUR INCHES. SCENE 43. CG, SUPER: TWISTING tape 339, 04:03:10-04:03:20 ANI: twisted part tape 339, 04:03:40-04:03:50 ANI: line appearing, showing part s twist SCENE 44. tape 249, 01:10:24-01:10:36 narrow strips twisting while shearing TWISTING IN THE SHEARED MATERIAL IS GENERALLY PROPORTIONAL TO THE RAKE OF THE UPPER KNIFE AND TO THE WIDTH OF THE DROP. NARROW STRIPS TWIST MORE THAN WIDE ONES, THICK MATERIALS MORE THAN THIN, AND SOFT MATERIALS MORE THAN HARD MATERIALS. --- FTB --- SCENE 45. tape 348, 00:01:10-00:01:21 pan of slitting line, from payoff reel, through slitter, to recoiler SLITTING IS COMMONLY USED IN THE COIL PROCESSING INDUSTRY, AND IS A SHEARING PROCESS IN WHICH SINGLE WIDTH COILED STOCK IS REDUCED LENGTHWISE INTO MULTIPLE NARROWER COILSSLITTING IS A COMMON PROCESS IN THE COIL PROCESSING INDUSTRY, AND IS A SHEARING PROCESS IN WHICH WIDE COILED STOCK IS

10 SLIT INTO MULTIPLE NARROWER COILS. SCENE 46. tape 348, 00:01:40-00:02:01 single loop slitting line in use CG, SUPER: SINGLE LOOP DOUBLE LOOP PULL THROUGH SLITTING IS ACCOMPLISHED USING A SLITTING LINE, OF WHICH THERE ARE THREE BASIC TYPES: THE SINGLE LOOP..., THE DOUBLE LOOP..., AND THE PULL THROUGH. SCENE 47. tape 348, 00:00:21-00:00:32 wide, slitting line CG, SUPER: UNCOILER REEL SLITTER TENSION DEVICE RECOILER THESE SLITTING LINES CONSISTS OF: AN UNCOILER OR PAY-OFF REEL, A SLITTER, A TENSION DEVICE, AND A RECOILER. SCENE 48. tape 348, 00:02:27-00:02:41 uncoiler reel rotating, feeding stock to slitter CG, SUPER: UNCOILER REEL THE UNCOILER REEL HOLDS THE MASTER COIL ON ITS INSIDE DIAMETER USING A MANDREL. THE COIL STOCK IS THEN FED TO THE SLITTER BY ROTATING THE MANDREL. SCENE 49. tape 348, 00:03:11-00:03:21 c.u. slitter with sheet stock passing through it CG, SUPER: SLITTER THE SLITTER HOLDS PARALLEL SHAFTS CONTAINING ROTARY CUTTING KNIVES. THE MATERIAL TO BE SLIT PASSES BETWEEN THESE KNIVES FOR A CONTINUOUS SHEAR. SCENE 50. tape 356, 01:00:40-01:00:50 ANI: coil graphic tape 356, 01:01:10-01:01:20 ANI: coil graphic, wipe on line tape 348, 00:04:17-00:04:32 pan from master coil to processed coils tape 348, 00:03:59-00:04:09 tensioning device taking up slack SINCE MOST MASTER COILS ARE CROWNED, OR BOWED IN THE CENTER, THE PROCESSED CENTER COILS WIND TO A LARGER OUTER DIAMETER THAN THE END COILS. THE RESULT IS THAT THE CENTER COILS PULL TIGHT AS THE

11 CG, SUPER: TENSIONING DEVICE END COILS HANG DOWN LOOSE. A TENSIONING DEVICE IS GENERALLY EMPLOYED BETWEEN THE SLITTER AND RECOILER TO ADJUST FOR THIS LENGTH DIFFERENTIAL PROBLEM. SCENE 51. CG, SUPER: RECOILER tape 348, 00:05:02-00:05:08 the recoiler taking up coils tape 348, 00:05:38-00:05:44 coils removed from recoiler THE RECOILER TAKES UP THE PROCESSED COILS ON A MANDREL, WHERE THEY ARE REMOVED ONTO AUXILIARY HANDLING EQUIPMENT. --- FTB --- SCENE 52. CG: SHEET METAL BENDING white text centered on black SCENE 53. tape 350, 15:04:00-15:04:20 c.u. of bending metal from end shot CG, SUPER: YIELD POINT CG, SUPER: TENSILE STRENGTH BENDING IS A METHOD OF PRODUCING SHAPES BY DEFORMING STRESSING THE METAL BEYOND ITS YIELD POINT, STRENGTH, WHICH IS THE MATERIAL S CAPABILITY TO RESIST PERMANENT DEFORMATIONMOVEMENT; BUT NOT PAST ITS ULTIMATE TENSILE STRENGTH, WHICH IS THE METAL S ABILITY TO RESIST TEARING. SCENE 54. tape 250, 02:25:43-02:25:56 part being bent tape 250, 02:04:14-02:04:20 part being sheared THE FORCES APPLIED DURING BENDING ARE IN OPPOSITE DIRECTIONS, JUST AS IN SHEARING. THE BENDING FORCES, HOWEVER, REST BETWEEN THE MATERIAL S YIELD POINT AND ITS TENSILE STRENGTH. IN SHEARING THE FORCES USED ARE WELL ABOVE THE MATERIAL S TENSILE STRENGTH. SCENE 55. tape 251, 03:16:01-03:16:07

12 part being bent tape 345, 01:04:16-01:04:25 ANI: blank being bent, opposing arrows showing bending forces, freeze last frame AS THE PART IS BENT, IT UNDERGOES A DISTORTION SO THAT THE MATERIAL OUTSIDE THE BEND IS FORCED TO STRETCH UNDER TENSION, AND THE MATERIAL INSIDE THE BEND IS FORCED TO COMPRESS. THUS, A PORTION OF THE PART'S CROSS SECTION IS PUT IN TENSION AND ANOTHER PORTION IN COMPRESSION. SCENE 56. tape 345, 01:04:28-01:04:33 ANI: continue previous shot, highlight line which is neutral axis, freeze last frame CG, SUPER: NEUTRAL AXIS tape 250, 02:14:32-02:14:36 part being bent BETWEEN THE TENSION AND COMPRESSION ZONES IS AN AREA WHERE THE MATERIAL IS NEITHER FORCED TO STRETCH NOR TO COMPRESS. THIS IS CALLED THE NEUTRAL AXIS. THE NEUTRAL AXIS IS IMPORTANT SINCE BENDING OPERATIONS ARE CALCULATED FROM ITS LOCATION. SCENE 57. tape 345, 01:04:34-01:04:40 ANI: close up view of previous animation, show lines scroll out from neutral axis, freeze last frame THE EXTENT TO WHICH A MATERIAL DEFORMS, WHETHER IN COMPRESSION OR TENSION, IS PROPORTIONAL TO THE MATERIAL S PERPENDICULAR DISTANCE FROM THE NEUTRAL AXIS. --- FTB ---WAY IN WHICH THE MATERIAL IS FORMED BY THE COMBINED ACTION OF TENSILE AND COMPRESSIVE FORCES DETERMINES THE LOCATION OF THE NEUTRAL AXIS WHICH IS USUALLY EXPRESSES AS A PERCENTAGE OF METAL THICKNESS FROM THE INSIDE BEND RADIUS. EXTENT TO WHICH A MATERIAL DISTORTS, WHETHER IN COMPRESSION OR TENSION, IS PROPORTIONAL TO THE MATERIAL S PERPENDICULAR DISTANCE FROM THE NEUTRAL AXIS. SCENE 58. tape 304, 00:11:48-00:12:00

13 ANI: bending on stamping die tape 346, 04:33:12-04:33:17 bending operation on bending machine tape 251, 03:09:49-03:10:00 press brake operating BENDING CAN BE PERFORMED IN DIES INON STAMPING PRESSES, AND ON VARIOUS OTHER TYPES OF EQUIPMENT. THE MOST COMMON OF THESE BENDING MACHINES IS THE PRESS BRAKE, CHIEFLY BECAUSE OF ITS VERSATILITY AND EASE OF OPERATION. SCENE 59. tape 250, 02:14:00-02:14:10 press brake prototype work PRESS BRAKES CAN BE USED FOR BOTH PROTOTYPE AND SHORT-RUN CUSTOM WORK, AS WELL AS FOR LENGTHY PRODUCTION RUNS. SCENE 60. tape 359, 06:20:44-06:20:53 wide, mechanical press brake tape 251, 03:15:23-03:15:31 wide, hydraulic press brake PRESS BRAKES CAN GENERALLY BE DIVIDED INTO TWO CATEGORIES: MECHANICAL..., OR HYDRAULIC, DEPENDING ON THE TYPE OF RAM DRIVE THAT IS USED. SCENE 61. tape 251, 03:10:26-03:10:34 wide, press brake tape 251, 03:11:32-03:11:45 tilt up of lower to upper parts of press brake CG, SUPER: BED RAM tape 250, 02:28:28-02:28:45 back gage, workpiece inserted, bent CG, SUPER: BACK GAGE THE PRINCIPAL COMPONENTS OF A PRESS BRAKE ARE: THE BED--WHICH IS THE PORTION OF THE MACHINE THAT SUPPORTS THE LOWER, OR FEMALE, DIE. THE RAM--WHICH HOLDS THE UPPER DIE, OR PUNCH. AND THE BACK GAGE--WHICH CAN BE EITHER A BAR OR FINGERS AT THE BACK OF THE PRESS BRAKE THAT POSITION THE WORKPIECE SO THE BEND IS MADE AT THE DESIRED POINT. SCENE 62. tape 250, 02:24:32-02:24:48 part place in press brake, bent tape 251, 03:14:19-03:14:40 part place in press brake, bed moving to ram to bend part IN A TYPICAL PRESS BRAKE BENDING OPERATION, A PIECE OF METAL IS PLACED BETWEEN THE UPPER AND LOWER DIES AND FORMED BY MEANS OF THE FORCE AND

14 PRESSURE EXERTED BY LOWERING THE RAM. ON SOME PRESS BRAKES, THE RAM AND UPPER DIES REMAIN STATIONARY WHILE THE BED HOLDING THE LOWER DIES PROVIDES THE FORCE THAT BENDS THE PART. SCENE 63. tape 345, 01:04:51-01:05:04 ANI: side view of press brake operation, showing three contact points SCENE 64. tape 356, 00:18:19-00:18:26 small die opening, part bent tape 356, 00:13:09-00:13:21 side view, large die opening, part bent THREE CONTACT POINTS ARE INVOLVED IN A BEND: THE TIP OF THE PUNCH AND TWO POINTS ON THE FEMALE DIE. THE MATERIAL IS BENT TO THE DESIRED ANGLE AS THE PUNCH ENTERS THE DIE. THE LARGER THE DIE OPENING, THE SMALLER THE FORCE REQUIRED TO FORM A GIVEN ANGLE. SCENE 65. continue previous shot tape 328, 06:02:00-06:03:00 blue background CG: BEND ALLOWANCE BEND ANGLE BEND RADIUS SPRINGBACK THE PRINCIPAL TERMS USED TO DESCRIBE BENDING ON PRESS BRAKES ARE: BEND ALLOWANCE, BEND ANGLE, BEND RADIUS, AND SPRINGBACK. SCENE 66. tape 345, 01:05:20-01:05:28 ANI: side view, flat blank, lines appear CG, SUPER: BEND ALLOWANCE tape 345, 01:05:32-01:05:39 ANI: part being bent BEND ALLOWANCE IS THE PRE-BENT LENGTH OF MATERIAL THAT MUST BE INCLUDED IN A BLANK TO ALLOW FOR ANY DEFORMATION THAT OCCURS DUE TO THE BENDING OPERATION. ANY CHANGE IN LENGTH ANY DISTORTION THAT OCCURS TO FORM AS THE PART IS FORMED THE PART DURING THE BENDING OPERATION. SCENE 67. tape 345, 01:05:41-01:05:44 ANI: part moves to center

15 tape 345, 01:05:48-01:05:54 ANI: same bent part, included angle of bent part appears CG, SUPER: BEND ANGLE tape 345, 01:06:03-01:06:12 lines changes to supplementary angle of two bent tangent lines SCENE 68. tape 345, 01:06:12-01:06:21 ANI: same bent part, bend radius indicated CG, SUPER: BEND RADIUS THE BEND ANGLE IS USUALLY THE INCLUDED ANGLE OF THE BENT WORKPIECE. IT CAN ALSO REFER TO THE SUPPLEMENTARY ANGLE FORMED BY THE TWO BENT TANGENT LINES. THE BEND RADIUS IS A TANGENT LINE WHERE THE FLAT, STRAIGHT SECTION OF THE PART STOPS AND THE RADIUS OF THE BEND BEGINS. SCENE 69. tape 345, 01:06:12:00 freeze of part, dissolve into animation CG, SUPER: SPRINGBACK tape 345, 01:06:21-01:06:25 ANI: same bent part, lines indicate angle, part springs back, line indicates spring back angle, freeze last frame SPRINGBACK IS THE TENDENCY OF THE MATERIAL TO MOVE TOWARDS RETURN TO ITS ORIGINAL FORM. SPRINGBACK TYPICALLY RANGES FROM TWO TO FOUR DEGREES. SCENE 70. tape 251, 03:10:12-03:10:21 c.u. bending on press brake tape 328, 06:02:00-06:03:00 blue background CG: AIR BENDING BOTTOM BENDING PRESS BRAKE BENDING IS DIVIDED INTO TWO MAJOR CATEGORIES: AIR BENDING, AND BOTTOM BENDING. SCENE 71. tape 350, 15:08:02-15:08:18 side view, c.u. air bending CG, SUPER: AIR BENDING IN AIR BENDING, THE PUNCH AND THE WORKPIECE DO NOT FULLY BOTTOM ON THE FEMALE DIE. THE WORKPIECE, SUPPORTED BY HIGH POINTS ON THE DIE, WRAPS AROUND THE TIP OF THE PUNCH TO FORM THE BEND. SCENE 72. tape 350, 15:04:59-15:05:16 complex part produced by air bending AIR BENDING IS HIGHLY VERSATILE SINCE A LARGE VARIETY OF BEND ANGLES CAN BE MADE FROM A SINGLE SET OF DIES.

16 SCENE 73. continue previous shot ANOTHER ADVANTAGE OF AIR BENDING IS THAT IT REQUIRES CONSIDERABLY LESS PRESS BRAKE FORCE TO PRODUCE A BEND--FOUR TO SIX TIMES LESS THAN IN BOTTOM BENDING. SCENE 74. tape 356, 00:14:15-00:14:26 c.u. air bending, part springs back SPRINGBACK IS A PARTICULAR PROBLEM IN AIR BENDING. ALLOWANCE FOR SPRINGBACK IS MADE BY OVERBENDING AND THEN PERMITTING THE WORKPIECE TO SPRING BACK TO THE DESIRED ANGLE. SCENE 75. tape 350, 15:07:45-15:07:58 side view, c.u. bottom bending of part CG, SUPER: BOTTOM BENDING SCENE 76. continue previous shot BOTTOM BENDING FORMS BENDS BY LETTING THE PUNCH FORCE THE WORKPIECE AGAINST THE LOWER DIE. IN GENERAL, BOTTOM BENDING PRODUCES MORE CONSISTENTLY ACCURATE PARTS THAN AIR BENDING. SCENE 77. tape 350, 15:06:49-15:07:05 bottom bending of part BOTTOM BENDING IS USUALLY USED FOR APPLICATIONS REQUIRING A HIGH DEGREE OF ACCURACY AND SHARP CORNERS. BECAUSE OF THE HIGH TONNAGE REQUIREMENT, BOTTOM BENDING IS GENERALLY LIMITED TO BENDING STEEL NO THICKER THAN TWELVE GAGE. ONE EIGHTH OF AN INCH OR APPROXIMATELY THREE MILLIMETERS. --- FTB --- SCENE 78. tape 251, 03:05:54-03:05:58 pan of lower dies tape 251, 03:06:16-03:06:22 pan of upper dies DIES ARE THE TOOLING THAT DETERMINE THE SHAPE

17 tape 251, 03:07:31-03:07:45 c.u. v -shaped die, bending tape 328, 06:02:00-06:03:00 blue background CG: ACUTE ANGLE DIE GOOSENECK DIE OFFSET DIE ROTARY BENDING DIE PRODUCED ON PRESS BRAKES. THE MOST COMMON TYPE OF BENDING DIE IS THE NINETY-DEGREE V -SHAPED DIE, BUT MANY OTHER TYPES ARE USED TO PRODUCE SHAPES, SUCH AS: THE ACUTE ANGLE DIE, THE GOOSENECK DIE, THE OFFSET DIE, AND THE ROTARY BENDING DIE. SCENE 79. tape 350, 15:08:19-15:08:25 acute angle die operation CG, SUPER: ACUTE ANGLE DIES ACUTE ANGLE DIES ARE USUALLY USED IN AIR BENDING WHERE ACCURACY IS NOT CRITICAL. SCENE 80. tape 350, 15:06:18-15:06:30 gooseneck die operation CG, SUPER: GOOSENECK DIES add arrow to show return flange CG IDENTIFY THE RETURN FLANGE GOOSENECK DIES ESSENTIALLY ARE V-BEND DIES WITH CLEARANCE FOR RETURN FLANGES. SINCE THE NECK OF THE DIE IS USUALLY OUT BEYOND CENTERLINE, CARE MUST BE TAKEN TO PREVENT OVERLOADING THE DIE. SCENE 81. tape 356, 00:21:48-00:21:58 offset die operation CG, SUPER: OFFSET DIES OFFSET DIES ARE TYPICALLY USED FOR LONG RUNS AND REQUIRE FROM FOUR TO TWENTY TIMES MORE FORCE FOR A SINGLE BEND DEPENDING ON THE NATURE OF THE OFFSET. SCENE 82. tape 356, 01:01:40-01:01:50 still, rotary bending die operation CG, SUPER: ROTARY BENDING DIES tape 356, 01:02:10-01:02:20 rotary bending die, clamping workpiece tape 356, 01:02:40-01:02:50 rotary bending die, midstroke tape 356, 01:03:10-01:03:20 rotary bending die, overbending ROTARY BENDING DIES USE A CYLINDRICAL ROCKER WITH AN EIGHTY-EIGHT DEGREE ANGULAR NOTCH CUT OUT ALONG ITS LENGTH. AS THE PUNCH DESCENDS, THE ROCKER CLAMPS THE WORKPIECE AND BENDS IT AROUND A DIE ANVIL. --- FTB ---

18 SCENE 83. tape 250, 02:13:14-02:13:37 c.u. multiple bends performed on part THE POSITION OF THE WORKPIECE AND THE STROKE OF THE PUNCH ARE CRITICAL VARIABLES IN THE BENDING PROCESS. COMPUTER CONTROLLED GAGES HAVE IMPROVED PRESS BRAKE ACCURACY, AND MADE POSSIBLE THE ECONOMICAL PRODUCTION OF MULTIPLE-BEND, MULTIPLE- STROKE PARTS IN A SINGLE SETUP. SCENE 84. tape 350, 15:04:07-15:04:27 c.u. cnc back gage changing to accommodate different bends in part THESE PROGRAMMABLE CNC CONTROLLED BACK GAGES ARE SERVO DRIVEN, AND CHANGE THEIR POSITION AUTOMATICALLY FOR MULTIPLE BENDS REQUIRED ON INDIVIDUAL PARTS. SCENE 85. continue previous shot CNC GAGING IS ALSO USED TO CONTROL THE DEPTH TO WHICH THE PUNCH PENETRATES THE LOWER DIE. --- FTB --- SCENE 86. tape 318, 02:25:16-02:25:22 folding machine creating bend SCENE 87. tape 319, 03:05:44-03:05:57 wide, folding machine feeding sheet stock from rear of machine tape 319, 03:11:30-03:11:42 c.u. material fed to upper and lower jaws FOLDING IS ANOTHER PROCESS USED TO BEND PARTS. A FOLDING MACHINE CONSISTS OF AN INTEGRATED SHEET SUPPORT AND GAGING SYSTEM THAT FEEDS RAW MATERIAL FROM THE REAR OF THE MACHINE TO A SET OF UPPER AND LOWER CLAMPING JAWS. SCENE 88. tape 318, 02:18:45-02:15:59 wide, folding beam turning up making bend tape 318, 02:20:57-02:21:06 c.u. folding beam turning up ONCE THE WORKPIECE IS POSITIONED AND CLAMPED, A FOLDING BEAM SWEEPS UPWARD, GENTLY CREATING THE

19 making bend DESIRED BEND ANGLE, ANYWHERE BETWEEN ZERO AND ONE HUNDRED AND EIGHTY DEGREES. SCENE 89. tape 319, 03:14:42-03:14:59 complex part being folded on folding machine FOLDING MACHINES ARE ESPECIALLY SUITABLE FOR LARGE OR COMPLEX PARTS REQUIRING MULTIPLE BENDS, SUCH AS METAL DOORS AND FURNITURE, ELECTRICAL ENCLOSURES, LIGHTING EQUIPMENT, ELEVATORS AND CONVEYORS. --- FTB --- SCENE 90. CG: REVIEW white text on black tape 63, 12:00:15-12:03:49 review music SCENE 91. tape 250, 02:04:58-02:05:05 sheet stock being sheared tape 326, 01:02:27-01:02:44 workers placing large sheet in shear, shearing sections LET'S REVIEW THE MATERIAL CONTAINED IN THIS VIDEOTAPE. SHEARING IS THE MECHANICAL CUTTING OF SHEET METAL BY MEANS OF TWO OPPOSING BLADES. IT IS USED TO PRECISELY CUT LARGE SHEETS OF PLATE AND SHEET STOCK INTO SMALLER, MORE MANAGEABLE SECTIONS, WHICH ARE THEN USED IN LATER OPERATIONS. SCENE 92. tape 249, 01:07:01-01:07:18 wide, lower blade affixed to bed, zoom in to upper blade attached to crosshead, shearing TYPICAL A SHEARS CONSIST OF A FIXED LOWER BLADE MOUNTED ON THE TABLE OR BED OF THE MACHINE..., AND AN UPPER BLADE SECURED ONTO A VERTICALLY MOVABLE CROSSHEAD. SCENE 93. tape 345, 01:01:26-01:01:50 ANI: blades coming together, penetrating the material until a crack or tear develops from both sides of the material, part separated AS THE BLADES PENETRATE THE MATERIAL, A CRACK OR TEAR--CALLED THE SLIP PLANE DEVELOPS ON BOTH SIDES OF THE MATERIAL, SEPARATING THE STOCK.

20 SCENE 94. tape 345, 01:02:11-01:02:19 ANI: yellow lines indicate the angle of upper blade alignment to lower blade, freeze last frame tape 345, 01:02:35-01:03:05 ANI: continue previous animation, upper blade contacting stock, fracture along line parallel to the knives ON MOST SHEARS THE UPPER KNIFE IS ALIGNED AT AN ANGLE OF BETWEEN ONE-HALF AND TWO-AND-A-HALF DEGREES TO THE LOWER BLADE. THIS ANGLE HELPS CONCENTRATE THE SHEARING FORCES, AND INSURES THAT THE SHEARED WORKPIECE--CALLED THE DROP --WILL NOT BECOME WEDGED BETWEEN THE TWO BLADES. SCENE 95. tape 326, 01:05:29-01:05:39 med, gapless shears cutting blanks tape 328, 06:02:00-06:03:00 blue background CG: GAPLESS SHEARS GAP SHEARS RIGHT-ANGLE SHEARS CNC SHEARS IRONWORKERS COMMON TYPES OF SHEARING EQUIPMENT INCLUDE: GAPLESS SHEARS..., GAP SHEARS..., RIGHT-ANGLE SHEARS..., CNC SHEARS..., AND IRONWORKERS. SCENE 96. tape 348, 00:01:10-00:01:21 pan of slitting line, from payoff reel, through slitter, to recoiler SLITTING IS A SHEARING PROCESS IN WHICH WIDE COIL STOCK IS SLIT LENGTHWISE INTO MULTIPLE NARROWER COILS ON SLITTING LINES. SCENE 97. tape 250, 02:16:39-02:16:47 bending operation BENDING IS THE CREATION OF THREE-DIMENSIONAL SHAPES OUT OF TWO-DIMENSIONAL MATERIAL. SCENE 98. tape 350, 15:04:00-15:04:20 c.u. of bending metal from end shot CG, SUPER: YIELD POINT CG, SUPER: TENSILE STRENGTH BENDING IS A METHOD OF PRODUCING SHAPES BY DEFORMING STRESSING THE METAL BEYOND ITS YIELD POINT, BUT NOT PAST ITS ULTIMATE TENSILE STRENGTH. SCENE 99. tape 251, 03:09:49-03:10:00

21 press brake operating THE PRESS BRAKE IS THE MOST COMMON KIND OF BENDING MACHINE. SCENE 100. tape 356, 00:14:15-00:14:26 c.u. air bending, part springs back CG, SUPER: AIR BENDING tape 350, 15:07:45-15:07:58 side view, c.u. bottom bending of part CG, SUPER: BOTTOM BENDING THERE ARE TWO MAJOR CATEGORIES OF BENDING: AIR BENDING..., AND BOTTOM BENDING. SCENE 101. tape 251, 03:07:31-03:07:45 c.u. v -shaped die, bending tape 350, 15:08:19-15:08:25 acute angle die operation CG, SUPER: ACUTE ANGLE DIES tape 350, 15:06:18-15:06:30 gooseneck die operation CG, SUPER: GOOSENECK DIES tape 356, 00:21:48-00:21:58 offset die operation CG, SUPER: OFFSET DIES tape 356, 01:01:40-01:01:50 still, rotary bending die operation CG, SUPER: ROTARY BENDING DIES NINETY-DEGREE V -SHAPED DIES ARE THE MOST COMMON TYPE OF BENDING DIE, BUT MANY OTHER TYPES ARE USED TO PRODUCE SHAPES, SUCH AS: ACUTE ANGLE DIES, GOOSENECK DIES, OFFSET DIES, AND ROTARY BENDING DIES. SCENE 102. tape 350, 15:04:07-15:04:27 c.u. cnc back gage changing to accommodate different bends in part THE ADDITION OF COMPUTER CONTROLLED GAGES TO PRESS BRAKES HAS GREATLY EXTENDED THEIR ACCURACY AND MADE POSSIBLE THE ECONOMICAL PRODUCTION OF MULTIPLE-BEND, MULTIPLE-STROKE PARTS IN A SINGLE SETUP. SCENE 103. tape 318, 02:18:45-02:15:59 wide, folding beam turning up making bend THE FOLDING MACHINES IS ALSO USED IN BENDING, AND IS ESPECIALLY SUITABLE FOR LARGE OR COMPLEX PARTS REQUIRING MULTIPLE BENDS. --- FTB ---

22 SCENE 104. CG: credits CREDITS: Produced By: The Society of Manufacturing Engineers Executive Producer: Steven Bollinger Producer/Director/Cameraman: Jerome T. Cook Written By: Robert Eade Graphics By: Joseph Brancik Jerome T. Cook Equipment Access Provided By: Electrolabs Machining & Fabricating Inc. Mercury Metalcraft Company Video Footage Provided By: Clearing Niagara Comeq, Inc. Finn Power International, Inc. Herr-Voss Corporation Integrated Fabricating Technologies, Inc. LVD Corporation Pullmax TRUMPF Inc.

23 Technical Assistance Provided By: Raymond E. Chalmers Frederick Mason Karen Wilhelm Richard G. Green, Summit Editorial Enterprises David Smith, Smith & Associates Eric Theis, Herr-Voss Corporation Production Assistance Provided By: Brad Schuchard Dave Wisniewski Video Editing: Grace & Wild Digital Studios Some machinery in this program had safety equipment removed to allow better recording of certain processes. Always read the safety information provided in the manufacturers manual before operating any machine. SCENE 105. CG: disclaimer Some machinery in this program had safety equipment removed to allow better recording of certain processes. Always read the safety information provided in the manufacturers manual before operating any machine. SCENE 106. tape 40, 01:00:00-01:00:12 ANI: SME logo