Work feeder controller

An automatic press work system comprising a press machine, said press machine having a crank shaft with a crank rotational angle, a work feeder having at least two movable shafts, at least two driving motors, each of said driving motors being for driving a respective movable shaft, and a work feeder controller for automatically moving said work feeder three-dimensionally in accordance with the crank rotation angle of said crank shaft for feeding a work into and out of a predetermined position in said press machine, wherein said work feeder controller comprises:

• a digital computer having a memory;
• an operation panel connected to said computer for inputting to said computer data for setting a motion curve for each of the movable shafts for a given work wherein each motion curve is representative of the relationship of the position of the respective movable shaft and the crank rotation angle necessary for the work feeder to execute operations to trace the respective motion curve, data for setting specification values of said driving motors, data for setting an operation start angle value for each of said movable shafts in terms of the rotational angle of said crank shaft at the time at which the respective one of said movable shafts starts to execute a particular operation, and data for setting an operation finish angle value for each of said movable shafts in terms of the rotational angle of said crank shaft at the time at which the respective one of said movable shafts finishes the execution of said particular operation;
• whereby said computer sets and stores in said memory said motion curve associated with the set stroke values of said motion curve, said specification value of said driving motor, each said operation start angle value, and each said operation finish angle value;
• said computer computing the allowable maximum operation stroke number for each of said movable shafts on the basis of the stored operation start angle value for the respective one of said movable shafts, the stored operation finish angle value for the respective one of said movable shafts, the stored set stroke values for the respective one of said movable shafts, and the stored specification value for the driving motor for the respective one of said movable shafts, and comparing the thus computed allowable maximum operation stroke number for each respective one of said movable shafts with a set stroke value for the respective one of said movable shafts for the purpose of evaluation of the thus compared set stroke value for each of said movable shafts.

A method for automatically controlling the three-dimensional movement of a work feeder in an automatic press work system, wherein the automatic press work system includes, in addition to said work feeder, a press machine having a crank shaft with a crank rotational angle, wherein said work feeder has at least one movable shaft and a driving motor for driving a respective movable shaft;

• said method comprising:
• storing at least one specification value of the driving motor for driving a respective movable shaft of said work feeder;
• setting and storing, in terms of said crank rotational angle, an operation start angle value representing the timing at which said respective movable shaft of said work feeder starts an operation;
• setting and storing, in terms of said crank rotational angle, an operation finish angle value representing the timing at which said respective movable shaft of said work feeder finishes the respective operation;
• setting and storing a motion curve of said respective movable shaft for a given work, including the set stroke values of the thus set motion curve;
• computing the allowable maximum operation stroke number of said respective movable shaft on the basis of the thus set and stored operation start angle value of said respective movable shaft, the thus set and stored operation finish angle value of said respective movable shaft, the thus set and stroked stroke values of said respective shaft, and the stored at least one specification value of the driving motor for said respective movable shaft;
• and
• comparing the allowable maximum operation stroke number for said respective movable shaft with a stet stroke value which has been set for said respective movable shaft, for the purpose of evaluation of the thus compared set stroke value for said respective movable shaft.