Tool and Device for Cold Expansion of Holes

A device for cold expansion of holes, comprising a first cylinder, in which a first piston with a piston rod is inserted, tot eh end of which the mandrel of the tool is coaxially clamped, with an axial hole, machined in the first piston and its piston rod, a second cylinder coaxial to the first with a second piston inserted in it, connected with a second piston rod, the end of which is statically connected to the pin of the tool, at least two chambers, formed by the spaces, enclosed by the two cylinders and their pistons and rods and driving and control systems, characterized in that the second piston (10) is inserted in the axial hole (8), in which, on the side of the mandrel, a distance sleeve (11) is statically clamped, and between the second piston (10) and the sleeve (11), a spring (12) working under pressure is inserted, the front faces (26) and (27) of the first piston (5) and second piston (10), the surface (28) of the axial hole (8) in the first piston (5), the surface (29) of the cylinder (4), the front face (96) and the inner round surface (95) of the sleeve (60) and the front face (30) of the bottom (31) of the cylinder (4) form a joint piston chamber (32), and the cylinder (4), the first piston (5) and its piston rod (6) form a rod chamber (34), coaxially to the cylinder (4), in direction to the split end of the mandrel (1), a flange (18) is statically clamped, its inner round surface (21), limiting the maximal diameter of the round surface, circumscribed around the round surfaces 922) of the working part (17) of the mandrel (1), between the first mandrel (5) and the bottom of the cylinder (4) a shoulder (24) is provided for, limiting the piston (5) stroke, and the systems for driving and control are joined in one joint driving-control system.