Tube bending machine

A tube bending machine having a memory wherein a program for bending a tube is stored, a gripping device which grips said tube at an end and selectively moves the tube in the axial direction of the tube and around the axis of the tube according to the program read out from said memory, and tube bending devices which bends the tube by a prescribed amount at a predetermined position on said tube, said machine comprising:

• a bending die having a peripheral surface in contact with said tube,
• a pushing die device capable of turning around a pivot shaft and capable of moving toward and away from the bending die and the tube in contact with the bending die, such that movement of the pushing die device toward the bending die engages the tube and such that the turning o the pushing die device around the pivot shaft is operative for bending said tube along the peripheral surface of said bending die,
• a photoelectric sensor which is installed on said pushing die device and detects said tube when the pushing die device is turned around the pivot shaft a sufficient amount for alignment of the photoelectric sensor with the tube, and
• a controlling unit to cause said pushing die device to be set according to said program, to be turned around said pivot shaft, ad to bend said tube so that the position of said tube detected by said sensor is brought close to a given value, whereby the pushing die device is turned around the pivot shaft with the pushing die device away from the tube such that the photoelectric sensor can detect the position of the tube, and whereby the controlling unit compares the detected position of the tube with the given value and determines whether additional bending by the pushing die device is required.