| 摘要 |
PURPOSE:To perform with high accuracy and simply and easily the mass production of the nozzle shaped tube stock with extra fine bore tip by performing a reduction wire drawing in one stage by the utilization of extrafine hard wire and the rotary descent motion of the die having special shaped super hard member. CONSTITUTION:Tube stock 1 is supported vertically by supporting stand 3 and the extrafine hard wire 2 of W, etc. having the outer diameter equal to the extrafine bore formed on the tip part and exceeding the total length of the tube stock 1 is inserted into the aperture thereof. The super hard member 5 made of ceramics in three pieces for instance to constitute the prescribed taper angle theta on the lower angle part is descended from the just upper part thereof with rotating the die 4 provided adjustably i its coming in and out in the centripedal direction. A taper step part 7a is formed in the medium of the tube stock 1 by the reduction wire drawing operation by the drawing aperture (h) of the shaft centre established by the in and out adjustment of the taper angle theta accompanying this descent operation and the member 5 group, also the tip beyond that is formed in the fine tube part 7b having the aperture 7c of extra fine bore. Finally the hard wire 2 is pulled away and nozzle shaped tube stock 7 is obtd. |
