Anglicky v odborných předmětech "Support of teaching technical subjects in English “

1. 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.

2. Roll forming – leveling; shearing

3. 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

4. Roll forming Here belongs: • Straightening • Shearing • Punching / Piercing • Bending • Sheet drawing

5. 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.

6. 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:

7. Roll forming • Straightening by rolling • For straightening of profiled material is necessary to profile rolls accordingly.

8. 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

9. Roll forming • Construction shearing knives divides shearing with: • parallel knives, • inkline knives, • disc knives, • knives for profiles and rods.

10. Roll forming • Process of shearing: • Compression • Actual shearing • Tearing

11. 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

12. Translate: • Hand lever shears Lever table shears • Mechanical table shears

13. 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.

14. Used literature • http://www.ksp.tul.cz/cz/kpt/obsah/vyuka/skripta_tkp/sekce/08.htm