l2 shearing and bending of metals.pptx
DESCRIPTION
entagTRANSCRIPT
![Page 1: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/1.jpg)
SHEARING AND BENDING OF METALS
![Page 2: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/2.jpg)
Sheet Metalworking
• Cutting and forming operations performed on relatively thin sheets of metal which are produced by rolling
• Thickness of sheet metal = 0.4 mm (1/64 in) to 6 mm (1/4 in)
• Thickness of plate stock > 6 mm• Operations usually performed as cold working
(except when the stock is thick or the metal is brittle then warm working is performed)
![Page 3: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/3.jpg)
Sheet and Plate Metal Products
• Sheet and plate metal parts for consumer and industrial products such as:
• – Automobiles and trucks• – Airplanes• – Railway cars and locomotives• – Farm and construction equipment• – Small and large appliances• – Office furniture• – Computers and office equipment
![Page 4: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/4.jpg)
Sheet Metal Processes
1. Cutting – Shearing to separate large sheets; or cut
part perimeters or make holes in sheets2. Bending – Straining sheet around a straight axis3. Drawing – Forming of sheet into convex or concave
shapes
![Page 5: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/5.jpg)
Advantages of Sheet Metal Parts
• High strength• Good dimensional accuracy• Good surface finish• For large quantities, economical mass
production operations are available
![Page 6: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/6.jpg)
Shearing operation• Several operations based on shearing performed Punching – sheared slug discardedBlanking – Slug is the part and the rest is scrap
Fig-16.4 -a
![Page 7: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/7.jpg)
Sitting and Shaving Operations
• FIGURE 7.10 Sitting with rotary knives. This process is similar to opening cans.
FIGURE 7.11 Schematic illustrations of shaving on a sheared edge. (a) Shaving a sheared edge. (b) Shearing and shaving, combined in one stroke.
![Page 8: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/8.jpg)
Shear Angles For Punches and Dies
• FIGURE 7.12 Examples of the use of shear angles on punches and dies.
![Page 9: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/9.jpg)
Progressive Dies
FIGURE 7.13 (a) Schematic illustration of the making of a washer in a progressive die. (b) Forming of the top piece of an aerosol spray can in a progressive die. Note that the part is attached to the strip until the last operation is completed.
![Page 10: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/10.jpg)
Tailor-Welded Blanks
• FIGURE 7.14 (a) Production of an outer side panel of a car body by laser welding and stamping. (b) Examples of laser welded and stamped automotive body components. Source: After M. Geiger and T. Nakagawa.
![Page 11: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/11.jpg)
Cutting
![Page 12: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/12.jpg)
Clearance in Sheet Metal Cutting
![Page 13: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/13.jpg)
Clearance in Sheet Metal Cutting
![Page 14: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/14.jpg)
Clearance in Sheet Metal Cutting
![Page 15: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/15.jpg)
Angular Clearance
![Page 16: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/16.jpg)
Cutting Forces
![Page 17: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/17.jpg)
Cutting Forces
![Page 18: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/18.jpg)
Progressive Dies
FIGURE 7.13 (a) Schematic illustration of the making of a washer in a progressive die. (b) Forming of the top piece of an aerosol spray can in a progressive die. Note that the part is attached to the strip until the last operation is completed.
![Page 19: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/19.jpg)
Progressive Die Sets• Progressive die sets- two or
more sets of punches and dies mounted in tandem
• Transfer dies move individual parts from operation to operation within a single press
• Compound dies combine processes sequentially during a single stroke of the ram Figure 17-16 Progressive piercing and blanking die
for making a square washer. Note that the punches are of different length.
![Page 20: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/20.jpg)
Compound dies :• Several operations on the same strip performed in one
stroke at one station with a compound dies
Fig 16.11 Schematic illustrations: (a) before and (b) after blanking a common washer in a compound die.note the separate movements of the die(or blanking) and the punch
![Page 21: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/21.jpg)
Transfer dies• Sheet metal undergoes different operations at different stations
in a straight line or circular path.
Tool and Die Material :• Carbides are used for high production rates.
![Page 22: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/22.jpg)
![Page 23: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/23.jpg)
Allowance for Multiblank thru Die
• 1. Between Blanks with pitch .....................T min.• 2. Between Blanks diagonally ..................T min.• 3. Blank to the Edge of Material ........ 0.5 T min.
![Page 24: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/24.jpg)
![Page 25: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/25.jpg)
![Page 26: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/26.jpg)
![Page 27: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/27.jpg)
![Page 28: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/28.jpg)
![Page 29: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/29.jpg)
![Page 30: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/30.jpg)
![Page 31: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/31.jpg)
![Page 32: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/32.jpg)
![Page 33: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/33.jpg)
![Page 34: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/34.jpg)
![Page 35: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/35.jpg)
![Page 36: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/36.jpg)
Springback is caused by the elastic recovery of the material upon unloading. The material tends to recover toward its originally flat shape. Overbend to compensate for springback
![Page 37: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/37.jpg)
![Page 38: L2 shearing and bending of metals.pptx](https://reader037.vdocuments.us/reader037/viewer/2022103113/554a5ae9b4c905522f8b4ffb/html5/thumbnails/38.jpg)