Abrégé

The present invention discloses an interlayer pre-cooling apparatus for a sand mold freezing printing,including a sand paving apparatus,where the sand paving apparatus is located above a negative-pressure low-temperature forming chamber, and the sand paving apparatus includes several independent sand paving grooves,a hollow sand paving roller, a cooling chamber, a sand scraping plate, and an openable and closable baffle; the openable and closable baffle is rotationally arranged at a discharge port of each sand paving apparatus, and the openable and closable baffle is used for paving low temperature premixed sand on demand.By providing cooling capacity for the hollow sand paving roller and the sand scraping plate, the premixed molding sand is further cooled during the process of scraping and compacting low-temperature molding sand. When the apparatus is adopted for sand mold freezing 3D printing,the low temperature of the premixed molding sand is precisely controllable, which has great significance for realizing interlayer pre-cooling of the sand mold freezing printing.

Classes IPC  ?

• B22C 1/18 - Compositions des matériaux réfractaires pour moules ou noyaux; Leur structure granulaire; Caractéristiques chimiques ou physiques de la mise en forme ou de la fabrication des moules caractérisées par l'emploi des agents liants; Mélange d'agents liants d'agents inorganiques
• B33Y 30/00 - Appareils pour la fabrication additive; Leurs parties constitutives ou accessoires à cet effet
• B33Y 40/00 - Opérations ou équipements auxiliaires, p.ex. pour la manipulation de matériau
• B33Y 70/00 - Matériaux spécialement adaptés à la fabrication additive
• B22C 9/02 - Moules en sable ou moules analogues pour pièces coulées

Abrégé

A throat shifting type fluidic vectoring nozzle for short-distance takeoff and landing is provided. The nozzle comprises: a tail section of an upper wall surface of a divergent- convergent section at a front portion of a second throat being selected as a translational component. In a level flight mode, the translational component is fitted with an upper fixing portion of the divergent- convergent section at the front portion of the second throat, to form an integral upper wall surface of the divergent-convergent section and be symmetrical to a lower nozzle wall surface. When switching from the level flight mode to a short-distance takeoff and landing mode, the translational component translates toward the lower rear along a motion track, and an air curtain component for blocking air flow is arranged between the translational component and the upper fixing portion to close the flow channel, thereby realizing convenient short-distance takeoff and landing.

Classes IPC  ?

• F02K 1/00 - Ensembles fonctionnels caractérisés par la forme ou la disposition de la tubulure de jet ou de la tuyère; Tubulures de jet ou tuyères particulières à cet effet