Abstract: The present invention provides a bending machine that enables an angle measuring instrument to be compactly built into a mold for accurate processing. The present invention also provides an operation method besed on learning control which achieves accurate bending with this bending machine taking spring back into consideration. A bending machine carries out bending using lineraly extending an upper die 4 and a lower die 2, the upper die 4 having a built-in angle measuring instrument 9. The angle measuring instrument 9 is composed of a corner contacting member 12 with links and an inductive linear position detector 13 for measuring displacement of the corner contacting member 12. In operation for learning, the position of and a load on the upper die 4 and a bend angle are measured during a bending process and a bend angle after spring back is subsequently measured.

Abstract: A driving device for a pressing machine, particularly effective on a turret punch press, whereby both high speed processing at times of low load and high load processing at low speeds can be carried out even with a low output motor. A driving device for a press machine that transmits the rotation of a motor 12 to a press system 11 via a rotation transmission system 29 having a speed reduction gear 30, wherein a speed change gear 31 intervenes on the rotation transmission system 29. The speed change gear 31 is arranged on the input side of the speed reduction gear 30. The press system 11 is a system for exchanging a rotation movement to a linear movement, reciprocally driving the punch tool 4 and comprises the toggle system 8 and the crank system 13 or the like. With regard to control, a method 36 for exchanging the rotation transmission ratio of the speed change system 31 corresponding to the type of process is arranged.

Abstract: A control apparatus which increases a hit rate, stabilizes a punch process, and makes use of a small motor. Such control apparatus is applicable to a punch drive apparatus that drives a punch tool by a servomotor via a ram and a toggle system. Such a structural arrangement includes a memory that memorizes a ram speed curve line from when the servomotor starts rotating to when the ram achieves a fixed speed; another memory that memorizes a surface height position of a sheet metal; and calculating device that calculates the lowest height of the ram at the aforementioned fixed speed when the punch tool reaches the surface of the sheet metal, and then sets a raised stand-by position of the ram. Such raised stand-by position is set in a ram shaft control device having the servo-controller.