Clamping device for inner holes of specially-structured thin-wall workpieces

The invention discloses a clamping device for inner holes of specially-structured thin-wall workpieces. The clamping device comprises a supporting shaft, wherein one end of the supporting shaft is mounted at a tail seat of a lathe, and three hydraulic oil cylinders are fixed on the peripheral wall of the other end of the supporting shaft and are distributed at a 120-degree interval along the circumference of the supporting shaft; piston rods of the hydraulic oil cylinders are fixedly connected with an inner arc-shaped surface of an circular arc-shaped supporting plate. By virtue of an arc-shaped supporting device with the adjustable supporting radius, the inner holes of the specially-structured thin-wall workpieces at two ends of the clamping device can be clamped, so that the subsequent process machining or assembling is facilitated, and the clamping is stable and reliable.