Bidirectional gate valve

The present invention is characterized by being comprised of: a blade (200) installed inside a valve housing (100) in the front surface and rear surface of which a first and second moving hole (110, 120) are formed, respectively, the blade (200) for opening and closing each of the moving holes (110, 120); a shaft (300) coupled to the lower portion of the blade (200); a first driving block (400) provided at the lower portion of the valve housing (100) and provided with a first cylinder (410) in which the shaft (300) is inserted, a first piston (420) installed inside the first cylinder (410), coupled to the bottom portion of the shaft (300), and moving the shaft (300) upward and downward according to the variation in pressure inside the first cylinder (410), and horizontally moving guide rollers (430, 430') provided on both external side surfaces, respectively, of the first driving block to guide the horizontal movement of the blade (200); a second driving block (500) coupled to be capable of moving upward and downward to the bottom portion of the first driving block (400) and having horizontally moving guide recesses (510, 510'), for guiding the horizontal movement of the blade (200,) formed in both inner side surfaces thereof, respectively, according to the upward and downward movement of the horizontally moving guide rollers (430, 430') inserted in the moving guide recesses; a third driving block (600) formed on the bottom portion of the second driving block (500) and including first and second seating portions (610, 620) respectively forming separate spaces therein, a second piston (611) coupled to the second driving block (500) in the first seating portion (610) and moving the second driving block (500) upward and downward according to the variation in pressure inside the first seating portion (610), and a movement restricting member (621) installed on the second seating portion (620) to be movable upward and downward and restricting the downward movement of the second piston (611); and a main body bracket (700) formed at the bottom portion of the valve housing (100) and housing the first, second, and third driving blocks (400, 500, 600).