METHOD OF TIGHT CLOSING OF BLANK TO MANDREL Russian patent published in 1998 - IPC

FIELD: metal machining by cutting, in particular, methods of fight closing of blanks to mandrel in their machining. SUBSTANCE: prior to process of cutting, periphery end face of sheet blank 1 is welded to mandrel 2 by argon-arc welding with formation of welding seam 3. Mandrel 2 is made with grooves 4 connecting with one another and with main channel 5. The latter may be sealed either by valve 6 or by welding seam 7. After securing blank 1 to mandrel 2 by welding, main channel 5 is connected to vacuum system, and air between blank and mandrel is evacuated. Sheet blank 1 is attracted to mandrel 2 due to difference in pressure values in space between them and ambient space. Upon attainment of definite vacuum, main channel 5 is sealed by means of valve 6 or by welding of hole 9 with the help of electron beam. Sealed device is disconnected from vacuum system and directed for working. After working, sheet is cut off in zone of welding seam 3 for its removal from mandrel 2. EFFECT: higher efficiency. 2 cl