The utility model relates to a horizontal
lathe center frame which comprises a center frame upper body and a center frame
lower body, the center frame upper body is arranged at the upper end of the center frame
lower body, and one end of the center frame upper body is rotatably connected with one end of the center frame
lower body through a pin shaft. The other end part of the center frame upper body is detachably connected with the other end part of the center frame lower body through a swing bolt; penetrating holes are formed in the upper end of the center frame upper body and the two ends of the center frame lower body, a guide cylinder is arranged in each penetrating hole, the upper end of each guide cylinder is connected with a steel
pipe sleeve, and a gland is arranged at the upper end of each steel
pipe sleeve; an ejector rod is arranged in each guide cylinder, an adjusting lead screw is arranged at the upper end of the gland, and the lower end of the adjusting lead screw downwards penetrates through the gland and extends into the steel
pipe sleeve to be rotationally connected with the ejector rods. Compared with the prior art, the steel pipe sleeve is arranged at the upper end of the guide cylinder, so that the maximum outer circle of a workpiece can be supported and positioned to be 860 mm, the production requirement is met, and the production cost is reduced.