Clamping jaw mounting device of vertical lathe

The invention discloses a vertical lathe clamping jaw mounting device which comprises a lathe chuck, a connecting plate and a lathe clamping jaw, a positioning groove is formed in the lathe chuck in the radial direction, sliding grooves are symmetrically formed in the two sides of the positioning groove, and two fixing nuts are slidably mounted in each sliding groove; a limiting protrusion is arranged on the upper surface of the connecting plate, a set of connecting plate mounting holes and a set of clamping jaw mounting holes are sequentially formed in the left side of the limiting protrusion, and a set of connecting plate mounting holes and a set of clamping jaw mounting holes are sequentially formed in the right side of the limiting protrusion in the same direction. The two connecting plate mounting holes close to the limiting protrusion are located in semicircular sinking grooves formed in the upper surface of the connecting plate respectively, and the straight edge of each semicircular sinking groove com