METHOD FOR MANUFACTURING HOLLOW ARTICLES AND DEVICE FOR ITS EMBODIMENT Russian patent published in 1998 - IPC

FIELD: plastic metal working; may be used in mechanical engineering in manufacture of thread bushings. SUBSTANCE: in manufacture of hollow articles, mainly, cylindrical bushings with two-way thread, circular blank embraced with flexible ring, is pressed out by means of simultaneous upsetting into slot hollow between top and female dies. Female die is used with thread surface whose profile is identical to thread surface of top die and is spaced from it at a distance equalling the thickness of thread wall of hollow article in radial direction. Assembly of circular blank and flexible ring with tool for extrusion, and also disassembly and removal of manufactured article are carried out beyond the working zone. The offered method is embodied in the device having female die, top die and thread surface coaxial to female die, clamp-container and flexible ring. Female die is made with thread surface and is connected by means of thread joint with top die having three stages. Thread is made on two stages of top die with continuous and same pitch, and the third stage is made in the form of cylindrical pilot for location in opening of clamp-container. Pilot has projection, and top die first stage has depression. EFFECT: higher material utilization factor, reduced labor input in manufacture of bushings and higher quality of bushings due to their manufacture by direct extrusion instead of machining. 3 cl, 5 dwg