HW7 ME 467 Page 1of 11QUESTIONS: FIRST, read the text Chapter 19 on sheet metal forming. Then, go to this link if you don’t have the DVD that came with the textbook, 5thedition: Then, select the 4 videos and view—“Shearing,” “Bending,”“sheet-metal stamping dies and processes,” and “”. 1.(Video) According to the video on sheet-metal shearing, a.What is the blade rake angle? b.For a shear angle of zero, would the required cutting force be greater or lesser than if the shear angler were non-zero (greater than zero)? Answer:a.The Blade Rake Angle or Shear Angle is the angle between the two surfaces that come together to shear the material. b.An angle of zero means that the shearing takes place at the same time along the entire surface, requiring a larger force to cut at any point in time verses a positive (non-zero) cutting angle. 2.(Video & Textbook) The definition of clearance is used in cutting calculations for what three types of sheet metal operations? Answer:the “clearance” term is used in shearing, blanking and punching.3.(Video) Name the four “common forming processes using press-mounted dies” noted in the video clip on “sheet-metal stamping dies and processes.”Answer:The four common forming processes using press-mounted dies listed in the video clip are (1) drawing, (2) bending, (3) flanging, and (4) hemming. 4.(Video)What are the two basic types of dies in sheet metal operations? Answer:The two basic types of dies are cutting and forming dies. 5.(Video)What type of sheet metal processes are used on perimeters or edges of a part? Name at least two. Answer:Flanging and hemming are the obvious ones. Allowed also is “Trimming”.6.(Video) The video refers to “bend allowance”in general, but the textbook refers to bend allowance calculated for a specific product physical characteristic. Which characteristic is it? a.Length (i.e, either side coming out of the bending brake) b.Thickness (the smallest dimension of a sheet metal coupon)
HW7 ME 467 Page 2of 11c.Width (the part dimension along the bending axis) d.Weight (mass) e.Angle (resulting degrees of bend) Answer:a. in other words—the bend allowance gets added in the length direction.