This invention discloses a gas
turbine cylinder block machining positioning device, belonging to the field of
machining clamping technology. The gas
turbine cylinder block includes an outer cylinder, an inner cylinder, a star-shaped support, and a support ring. Multiple height-adjustable support mechanisms include support seats and movable supports. The movable supports are provided with normal positioning parts and tangential positioning parts. The top
protection mechanism includes a guide plate, a first variable
diameter plate, multiple sector plates, and multiple second positioning parts that can move synchronously radially. The guide plate is provided with multiple first straight grooves and second straight grooves. The first variable
diameter plate is provided with multiple first arc-shaped grooves and connected to a second drive
assembly. The multiple sector plates are stacked, and the sector plates are provided with first pins that cooperate with the first straight grooves and first arc-shaped grooves and second pins that cooperate with the second straight grooves. This invention uses height-adjustable support mechanisms to position the outer cylinder,
resist shear force and
axial force, and ensure support rigidity. It also cooperates with the top
protection mechanism to make the axes of the support ring, outer cylinder, and inner cylinder collinear.