Section 5: Sheet Metalworking Flashcards
Categories of Sheet Metalworking
Performed on presses:
-Sheet metal cutting:
- Sheet metal shearing
- Sheet metal blanking
- Sheet metal punching
- Sheet metal bending:
- V-bending
- Edge bending
- Drawing
Not performed on presses
- Stretch forming
- Roll bending
- Roll forming
- Spinning
Define Sheet Metalworking
Cutting and forming operations performed on relatively thin sheets of metal:
- Thickness of foil <= 0.4mm
- Thickness of sheet metal = 0.4mm-6mm
- Thickness of plate stock > 6mm
Are Sheet metalworking operations usually hot or cold working
cold working
What is the thickness of the foil for sheet metalworking
<= 0.4mm
What is the thickness of sheet metal in sheet metalworking
0.4 mm - 6 mm
Thickness of plate stock in sheet metalworking
> 6mm
Advantages of Sheet Metal Parts
- High strength
- good dimensional accuracy
- good surface finish
- relatively low cost
- economical mass production for large quantities
Punch and die
tooling to perform cutting, bending, and drawing
Stamping press
Machine tool that performs most sheet metal operations
Stampings
sheet metal products
Sheet Metal Shearing
Category of sheet metal cutting to separate large sheets
Sheet Metal Blanking
Category of sheet metal cutting to cut part perimeters of sheet metal
Sheet Metal Punching
Category of sheet metal cutting to make punch holes in sheet metal
Sheet Metal Bending
Straining Sheet around a straight axis
Sheet Metal Drawing
Forming of sheet into convex or concave shapes
Scrap and part in Blanking
- Blank is the part (interior of the cut)
- Strip is the scrap (exterior of cut)
Scrap and part in punching
Part is the exterior
- Slug is the scrap (hole punched out)
In sheet metal bending, what happens to the inside and outside of the neutral plane?
Metal on the inside of the plane is compressed, and the metal outside of the plane is stretch
Like turning the Letter I into the letter C
V-bending
-performed with a V-shaped die
- low production (smaller Q)
- performed on a press brake
- v-dies are simple and inexpensive
Edge Bending
- performed with a wiping die
- high production (Larger Q)
- pressure pad required
- Dies are more complicated and costly
Sheet metal drawing process and products and other name
Process: sheet metal blank is positioned over a die cavity and then punched into opening
Products: cans, car body panels
AKA Deep Drawing
Most press-working operations are performed with what tooling and why?
punch and die tooling
- Custom-designed for a particular part
A name for high production dies
stamping die
Sheet metalworking operations not performed on presses
- stretch forming
- roll bending and forming
- spinning
Stretch forming
sheet metal is stretched and simultaneously bent to achieve shape change
Roll Bending
Large metal sheets and plates are formed into curved sections using rolls
Roll Forming
Continuous bending process in which opposing rolls produce long sections of formed shapes from coil or strip stock
What is Spinning and its three types
Sheet metal forming process in which an axially symmetric part is gradually shaped over a rotating mandrel using a rounded tool or roller
Three types:
- Conventional spinning
- shear spinning
- tube spinning
Conventional spinning vs Shear spinning
Conventional spinning leaves the thickness of the sheet metal unchanged. Shear spinning reduces it
How does Conventional spinning work?
bends the metal around a moving circular axis to conform to the outside surface of the axisymmetric mandrel. The thickness of the metal therefore remains unchanged
How does shear spinning work
outside diameter remains constant therefore wall thickness is reduced
Tube Spinning
Tube spinning is used to reduce the wall thickness and increase the length of a tube by means of a roller applied to the work over a cylindrical mandrel.
Similar to shear spinning but in a tube rather than a flat disk
