PURPOSE: To manufacture an Al tube elbow having small inside bending radius by pressing a blank tube in the direction of bent part of a die by fluid pressure, and at the same time, applying fluid pressure to the inside of the tube and extruding the tube along the bent tube part.

CONSTITUTION: A blind cover 14 is fixed as air-tight by welding etc. to an end face of a straight blank tube 12. A tube holder 3 is fitted to the opening of the tube 12. A piston 2 is moved by fluid pressure from a fluid channel 1b, and the tube 12 is pressed in the direction of a bent tube part 6 through the tube holder 3. At the same time, pressure fluid from a fluid channel 1C is introduced into the tube 12. The tube 12 is extruded to the right and bent along the bent tube part (b) of a die, and a part becomes in a bent state. Under this condition, the blind cover 14 comes into contact with a urethane rubber layer inserted beforehand in the bent tube part (b) of the die, and presses the urethane rubber by pressure fluid from a flow channel 1b while preventing damage due to welding of the blind cover. Bending of the tube 12 is advanced thereby. On the other hand, bending is performed by specified rise of pressure by retreating a supporting plate 10 downward. After bending, both ends of the elbow are cut off, and the blind cover is removed.