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Anglicky v odbornch pedmtech"Support of teaching technical subjects in EnglishTutorial: Engineering technology

Topic : Roll forming leveling, shearing

Prepared by: Ing. Elena Nov

Projekt Anglicky v odbornch pedmtech, CZ.1.07/1.3.09/04.0002je spolufinancovn Evropskm socilnm fondem a sttnm rozpotem esk republiky.

Roll forming leveling; shearing

Roll forming rolling technics It is cold material forming. At roll forming materials cross section (sheets or profiles) is not altered.Advantages of this type of forming:High productivityLow production costsLow material wasteGood condition for automatization

Roll forming

Here belongs: StraighteningShearingPunching / Piercing BendingSheet drawing

Roll forming

1. Straightening Is a technology used for removal of deformation due to wrong manipulation and/or during production. Press compression is actually an inverse bend, where are straitened curved parts. Roll forming

For straightening are used either jaws or rolls. If flat jaws are chosen, forming force is to be increased after connection to overcome residual forces from previous process so called calibration. Straightening pitched (left) and embossed (right)is used with very thin and/or hard sheets:Roll forming

6Straightening by rolling

For straightening of profiled material is necessary to profile rolls accordingly. Roll forming

2. Shearing is divided according to process temperature:

Cold shearing only for softer steel (tensile strength 400 MPa) and sheets

Hot shearing for harder and thicker materials at heating up temperature of 700 deg.C

Roll forming

Construction shearing knives divides shearing with: parallel knives, inkline knives, disc knives, knives for profiles and rods.

Roll forming

Roll forming Process of shearing:CompressionActual shearingTearing

Roll forming Principe and shearing forces:With parallel knives:1 upper moving knife, 2 bottom fixed knife, 3 holder, 4 sheared materialAngle of cutting edge is 75 to 85 degree

Hand lever shears Lever table shears

Mechanical table shearsTranslate:

What temperature is used for roll forming?Advantages of roll forming?Name principal processes used in pressing and stamping. Sketch pitched and embossed straightening.For straightening two processes are used. Name them. Name processes of shearing. Answer questions:

http://www.ksp.tul.cz/cz/kpt/obsah/vyuka/skripta_tkp/sekce/08.htmUsed literature