| 摘要 |
<p>The machine, which comprises a steam drum (1) capable of providing a blown air stream through the diffuser (2) towards the mold box (3), is characterized by a specific valve system whereby a tubular valvular body (7) is fixed to the mouth (9) of the steam drum (1) with the collaboration of a support frame (8). The diffuser (2) is also connected to the tubular valve body (7); together with a large central core (15), the assembly defines a peripheral passage (16) for the exit of air, an internal valve seat (14) being set therein for a tubular membrane (11) fixed by its edge regions to the edge region of the valvular body (7), thereby defining externally a surrounding chamber (12) which, when pressurized, causes the strangulation of the membrane (11) against the seat (14) and consequently the valve closure. The opening of the valve (11-14) determines, through the diffuser (2), a jet of air which is concentrate essentially on the perimetral area of the molding box (3), thereby improving the compaction of the sand (5).</p> |
