Core box unit used for precisely casting and provided with guiding and positioning latch mechanism

The invention discloses a core box unit used for precisely casting and provided with a guiding and positioning latch mechanism, aiming at solving the problems in the prior art that the coaxiality of a core box is out of tolerance and displacement occurs in buckling when a left half core box and a right half core box are combined. The core box unit is characterized in that a positioning pin (8) is arranged on a left half core box unit combined vertical rib plate (5); a door-shaped catch seat (9) is fixed on the outer side surface of the left half core box unit combined vertical rib plate (5); a door-shaped retaining ring (10) is movably arranged on the door-shaped catch seat (9); a positioning pin sleeve is arranged on a right half core box unit combined vertical rib plate (6); a latch segment (11) is arranged on the outer side surface of the right half core box unit combined vertical rib plate (6); the positioning pin (8) and the positioning pin sleeve are movably inserted together; the door-shaped retaining ring (10) movably arranged on the door-shaped catch seat (9) and the latch segment (11) are movably buckled together. According to the invention, the precision of the internal size of the core box is ensured, and the quality of a product is improved.