CUTTING BLADE FEEDING DEVICE FOR SHEARING MACHINE

PURPOSE:To set the switching time of the feeding speed of an upper blade automatically by providing a speed switching circuit for setting the switching time, which switches the speed of an upper blade between the quick feeding to a member to be cut and the cutting feeding into the member to be cut, in an upper blade elevating mechanism. CONSTITUTION:A cutting blade feeding device is provided with an elevating mechanism 5 for lowering an upper blade 4 from the back position thereof to a position close to a member W to be cut, switching the speed between a predetermined quick feeding speed and the cutting speed into the member W to be cut and a control mechanism 22 for controlling the elevating mechanism 5. This control mechanism 22 subtracts the plate thickness of a member W to be cut from a distance between the upper blade 4 at the back position and a lower blade 3, and computes a distance of the quick feeding to a position close to the member W to be cut, and sets the switching period of the quick feeding and the cutting feeding into the member W to be cut with a speed switching circuit 28 on the basis of the computed distance, and the speed is switched by the control mechanism 22 automatically.