摘要:
A method for manufacturing light alloy castings by die casting with disposable cores, including a mold filling phase in which the parameters of pressure and speed of the molten alloy are controlled at levels tolerable by the cores until the cavities around the latter are filled by the molten alloy, and thereafter the pressure and speed parameters are controlled at levels suitable for completing and compacting the casting, the alloy being kept at a temperature close to its melting temperature throughout the whole path between the pump that pressurizes it and the entrance to the cavities around the cores. The invention relates also to a plant implementing said method by means of a pump connected to a mold through a duct that comes out within the casting envelope at a point close to the centroid of the cores.
摘要:
A method for manufacturing light alloy castings by die casting with disposable cores, including a mold filling phase in which the parameters of pressure and speed of the molten alloy are controlled at levels tolerable by the cores until the cavities around the latter are filled by the molten alloy, and thereafter the pressure and speed parameters are controlled at levels suitable for completing and compacting the casting, the alloy being kept at a temperature close to its melting temperature throughout the whole path between the pump that pressurizes it and the entrance to the cavities around the cores. The invention relates also to a plant implementing said method by means of a pump connected to a mold through a duct that comes out within the casting envelope at a point close to the centroid of the cores.
摘要:
System to feed and discharge materials continuously for the rehabilitationf railway road beds and the like in cooperation with operational machines (21) coupled to a plurality of waggons (10) storing such materials, in which system each storage waggon (10) comprises:hopper (11) to contain materials, with lower movable shutters (12) to open and close the hoppers (11),a lower conveyor (13) cooperating with the hoppers (11) and extending substantially along the whole length of the waggon (10) in a horizontal plane,a upper conveyor (14) extending substantially along the whole length of the waggon (10) in a horizontal plane, andan almost vertical conveyor (16) cooperating with the lower conveyor (13) in the transfer of materials.
摘要:
A pump for the hot chamber die casting of corrosive light alloys including a body (2) wherein a cavity (3) is formed in which a piston (4) vertically reciprocates and on whose side wall (5) an opening (11) for the introduction of the molten alloy (1) and the mouth of a sprue (9) for the connection with the mold (10) are formed. The diameter of the piston (4) is smaller than that of the cavity (3) so that it may move without rubbing on the wall (5) as it is guided by a seal packing (6) detachably constrained to the mouth of the cavity (3), the opening (11) being closed during the compression of the alloy in the cavity (3) by a valve (12) controlled from outside through a lever (13).
摘要:
Rehabilitation machine (10) for railway road beds, which comprises a framework (11) rested on a front bogie (12) and rear bogie (13), cabs (14-15) to drive the machine during its travels, an excavation chain (20) cooperating with a hopper (21) in the transfer of excavated material onto an elevator (22), and a leading end (24) and trailing end (124) relative to the direction of advance (19) of the machine (10), and also comprises at one end a first front conveyor (27) to deliver a mixture of aggregate materials (26) and a second front conveyor (33) to deliver metalling (32) towards the machine (10) and also discharge conveyors (23) to discharge excavated material from the machine (10).
摘要:
A sealing and guiding device for the injection piston (3) of a hot chamber pump for corrosive alloys made up of a body (1) in which a chamber (6) and an injection cavity (2) therebelow are formed, wherein the piston (3) slides with a vertical reciprocating motion (V), includes a bush (8), having an outer diameter smaller than said chamber (6), interposed between centering members housed in the chamber (6) and made coaxial with the chamber (6) and with the piston (3) by a pair of opposite surfaces of revolution (12, 13) formed on said centering members, the upper surface (13) and the relevant centering member performing a pressure-tight sealing. The outer lateral surface (15) of the bush (8) is in communication with the injection cavity (2) whereas the upper side of the bush (8) is in communication with the crucible and immersed therein at a depth (L), measured from the lowest level (23) reachable by the molten alloy, which is greater than the maximum travel (C) of the piston (3). The inner surface (21) of the bush (8) is a surface of revolution with diameter just larger than the piston (3).
摘要:
Machine to clean and rehabilitate railway ballast and railway road beds, which can: (1) remove the ballast, clean the ballast and then replace the ballast, or (2) remove the old ballast and replace it with new ballast. The machine, while riding on the railroad tracks, can remove the metalling of the ballast from the railroad track, then run the material through a riddle to clean the metalling, and finally replace the material. Alternatively, the machine may remove the metalling, then by reversing the direction of a distrubution conveyor, the machine can replace the old metalling with entirely new metalling brought to the distribution conveyor by various feed conveyors. In this alternative mode of operation, the machine can lay a two layered ballast consisting of two different materials.
摘要:
An apparatus for the hot-chamber die casting of non-ferrous alloys essentially consists of a press (115) for the closing/opening of a mould (110, 111) and an injection group (112) comprising a pump body (102) immersed in a pot (124) of the molten alloy and in which an injector piston (116) slides, an actuator (108) connected to the injector piston (116), and a gooseneck formed of in the pump body (102) and ending with a heated extension (103) provided with a nozzle (104) for the connection to the mould (110, 111), two hydraulic jacks (114) being secured between the injection group (112) and the press (115) which is fixed, the injection group (112) being divided into a stationary bottom portion and a top portion movable on sloped guides (109) parallel to the longitudinal axes of the extension (103) and of the hydraulic jacks (114), the pot (124) being mounted on horizontal rails (120) and the hydraulic jacks (114) being secured to the pump body (102).
摘要:
An injection pump for the hot-chamber die casting of corrosive light alloys includes a body provided with an internal coaxial liner where an injector piston sealingly slides. The liner being made of a material resistant to the molten alloy and has a coefficient of thermal expansion different from the material of the body. Static sealing elements, made of a graphite-based non-metallic material that yields under compression, are arranged between the internal surface of the body and the external surface of the liner. The pump also has axial compression means arranged between a ring nut screwed into the body and the liner and the static sealing elements.
摘要:
An injection pump for the hot-chamber die casting of corrosive light alloys includes a body provided with an internal coaxial liner where an injector piston sealingly slides. The liner being made of a material resistant to the molten alloy and has a coefficient of thermal expansion different from the material of the body. Static sealing elements, made of a graphite-based non-metallic material that yields under compression, are arranged between the internal surface of the body and the external surface of the liner. The pump also has axial compression means arranged between a ring nut screwed into the body and the liner and the static sealing elements.