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Learn about the cold material forming technique of roll forming and the various processes involved, such as straightening and shearing. Discover the advantages and methods used in this essential engineering technique.
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Anglicky v odborných předmětech"Support ofteachingtechnicalsubjects in English“ Tutorial: Engineering technology Topic : Rollforming – leveling, shearing Prepared by: Ing. Elena Nová Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002 je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky.
Roll forming Roll forming –rolling technics It is cold material forming. At roll forming material’s cross section – (sheets or profiles) is not altered. Advantages of this type of forming: • High productivity • Low production costs • Low material waste • Good condition for automatization
Roll forming Here belongs: • Straightening • Shearing • Punching / Piercing • Bending • Sheet 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 • Straightening 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 700deg.C
Roll forming • Construction shearing knives divides shearing with: • parallel knives, • inkline knives, • disc knives, • knives for profiles and rods.
Roll forming • Process of shearing: • Compression • Actual shearing • Tearing
Roll forming • Principe and shearing forces: • With parallel knives: • 1 – upper moving knife, 2 – bottom fixed knife, 3 – holder, 4 – sheared material • Angle of cutting edge β is 75 to 85 degree
Translate: • Hand lever shears Lever table shears • Mechanical table shears
Answer questions: • 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.
Used literature • http://www.ksp.tul.cz/cz/kpt/obsah/vyuka/skripta_tkp/sekce/08.htm