Method and device for closed-loop control of ram movement and ram forces in multi-point servo hybrid presses

A device to control a ram movement and of ram forces of a servo-electric warm-forming machine, the servo-electric warm-forming machine comprising:

• a multi-point servo hybrid press comprising,
• a ram which is configured to move vertically, the ram comprising pressure points each of which comprises a hydraulic pressure cushion, the pressure points comprising a first pressure point or a first pressure point group and a second pressure point or a second pressure point group,
• at least two servo motors each of which is configured to provide a rotational movement, the at least two servo motors comprising a first servo motor which is assigned to the ram and to the first pressure point or to the first pressure point group and a second servo motor which is assigned to the ram and to the second pressure point or to the second pressure point group,
• at least two cam gears, the at least two cam gears comprising a first cam gear and a second cam gear, the first cam gear being configured to convert the rotational movement of the first servo motor into a linear movement, and the second cam gear being configured to convert the rotational movement of the second servo motor into a linear movement,
• at least two pull rods, the at least two pull rods comprising a first pull rod and a second pull rod, the first pull rod being operatively connected to the first cam gear and being configured to be provided with the linear movement so as to drive the ram via the first pressure point or via the first pressure point group, and the second pull rod being operatively connected to the second cam gear and being configured to be provided with the linear movement so as to drive the ram via the second pressure point or via the second pressure point group,
• a force sensor configured to detect an actual force value feedback, and
• a temperature sensor configured to detect an actual temperature value feedback,
• the device comprising:
• an NC control device which is configured to control at least one of a position, a speed and a force of each hydraulic pressure cushion of the pressure points of the ram, the NC control device comprising:
• a positional cam profile which is configured to control at least one of a position, a speed, a torque and a force of the at least two servo motors for driving the pressure points of the ram, the positional cam profile being controlled by a virtual control shaft;
• a sequential control;
• a storage device for machine and die data;
• a first functional unit for calculating pressure point-specific curves of a target force value for each hydraulic pressure cushion;
• a second functional unit for a force control of each hydraulic pressure cushion;
• a third functional unit for calculating pressure point-specific curves of a target position with initial correction values;
• a fourth functional unit for a position control of the pressure points of the ram as a main function;
• a fifth functional unit for calculating pressure point-specific force correction values, input values of the fifth functional unit being measured signals of the actual force value feedback and the actual temperature value feedback, and output values of the fifth functional unit when summed together with output values of the first functional unit for calculating the pressure point-specific curves of the target force value determine input values into the second functional unit for the force control of each hydraulic pressure cushion;
• and
• a sixth functional unit for calculating pressure point-specific positional offsets, input values of the sixth functional unit being measured signals of the actual force value feedback, and output values of the sixth functional unit when summed together with output values of the third functional unit for calculating the pressure point-specific curves of the target position with initial correction values and the actual temperature value feedback determine input values into the fourth functional unit for the positional control of the pressure points of the ram.

A device to control a ram movement and a ram force of a servo-electric warm-forming machine, the servo-electric warm-forming machine comprising:

• a multi-point servo hybrid press comprising,
• a ram which is configured to move vertically, the ram comprising pressure points each of which comprises a hydraulic pressure cushion, the pressure points comprising a first pressure point or a first pressure point group and a second pressure point or a second pressure point group,
• at least two servo motors each of which is configured to provide a rotational movement, the at least two servo motors comprising a first servo motor which is assigned to the ram and to the first pressure point or to the first pressure point group and a second servo motor which is assigned to the ram and to the second pressure point or to the second pressure point group,
• at least two cam gears, the at least two cam gears comprising a first cam gear and a second cam gear, the first cam gear being configured to convert the rotational movement of the first servo motor into a linear movement, and the second cam gear being configured to convert the rotational movement of the second servo motor into a linear movement,
• at least two pull rods, the at least two pull rods comprising a first pull rod and a second pull rod, the first pull rod being operatively connected to the first cam gear and being configured to be provided with the linear movement so as to drive the ram via the first pressure point or via the first pressure point group, and the second pull rod being operatively connected to the second cam gear and being configured to be provided with the linear movement so as to drive the ram via the second pressure point or via the second pressure point group,
• a press bed,
• a bottom die arranged on the press bed,
• a top die operatively connected to the ram, and
• a process cushion arranged in at least one of the ram, the press bed, the bottom die, and the top die,
• the device comprising:
• an NC control device which is configured to control at least one of a position, a speed and a force of the process cushion for a second auxiliary function, the NC control device comprising:
• a positional cam profile which is configured to control at least one of a position, a speed, a torque and a force of the at least two servo motors for driving the pressure points of the ram, the positional cam profile being controlled by a virtual control shaft;
• a first functional unit for a sequential control;
• a second functional unit to store machine and die data;
• a third functional unit for calculating cushion-specific curves of a target force value for the process cushion;
• a fourth functional unit for a force control of the process cushion;
• a fifth functional unit for calculating target position curves for the pressure points of the ram with correction;
• and
• a sixth functional unit for a position control of the pressure points of the ram as a main function.

A device to control a ram movement and of ram forces of a servo-electric warm-forming machine, the servo-electric warm-forming machine comprising:

• a multi-point servo hybrid press comprising,
• a ram which is configured to move vertically, the ram comprising pressure points each of which comprises a hydraulic pressure cushion, the pressure points comprising a first pressure point group and a second pressure point group,
• at least two servo motors each of which is configured to provide a rotational movement, the two servo motors comprising a first servo motor which is assigned to the ram and to the first pressure point group and a second servo motor which is assigned to the ram and to the second pressure point group,
• at least two cam gears, the at least two cam gears comprising a first cam gear and a second cam gear, the first cam gear being configured to convert the rotational movement of the first servo motor into a linear movement, and the second cam gear being configured to convert the rotational movement of the second servo motor into a linear movement,
• at least two pull rods, the at least two pull rods comprising a first pull rod and a second pull rod, the first pull rod being operatively connected to the first cam gear and being configured to be provided with the linear movement so as to drive the ram via the first pressure point group, and the second pull rod being operatively connected to the second cam gear and being configured to be provided with the linear movement so as to drive the ram via the second pressure point group,
• a press bed,
• a bottom die arranged on the press bed,
• a top die operatively connected to the ram,
• a process cushion arranged in at least one of the ram, the press bed, the bottom die, and the top die,
• a force sensor configured to detect an actual force value feedback, and
• a temperature sensor configured to detect an actual temperature value feedback,
• the device comprising:
• an NC control device which is configured to control at least one of a position, a speed and a force of the process cushion for a second auxiliary function, the NC control device comprising:
• a positional cam profile which is configured to control at least one of a position, a speed, a torque and a force of the at least two servo motors for driving the pressure points of the ram, the positional cam profile being controlled by a virtual control shaft;
• a sequential control;
• a storage device for machine and die data;
• a first functional unit for calculating cushion-specific curves of a target force value for the process cushion;
• a second functional unit for a force control of the process cushion;
• a third functional unit for calculating pressure point-specific curves of a target position with initial correction values;
• a fourth functional unit for a position control of the pressure points of the ram as a main function;
• a fifth functional unit for calculating cushion-specific force correction values, input values of the fifth functional unit being measured signals of the actual force value feedback and the actual temperature value feedback, and output values of the fifth functional unit when summed together with output values of the first functional unit for calculating the cushion-specific curves of the target force value determine input values into the second functional unit for the force control of the process cushion;
• and
• a sixth functional unit for calculating pressure point-specific positional offsets, input values of the sixth functional unit being measured signals of the actual force value feedback, and output values of the sixth functional unit when summed together with the output values of the third functional unit for calculating the pressure point-specific curves of the target position with initial correction values and the actual temperature value feedback determine input values into the fourth functional unit for the positional control of the pressure points of the ram.

A device to control a ram movement and of ram forces of a servo-electric warm-forming machine, the servo-electric warm-forming machine comprising:

• a multi-point servo hybrid press comprising,
• a ram which is configured to move vertically, the ram comprising pressure points each of which comprises a hydraulic pressure cushion, the pressure points comprising a first pressure point group and a second pressure point group,
• at least two servo motors each of which is configured to provide a rotational movement, the at least two servo motors comprising a first servo motor which is assigned to the ram and to the first pressure point group and a second servo motor which is assigned to the ram and to the second pressure point group,
• at least two cam gears, the at least two cam gears comprising a first cam gear and a second cam gear, the first cam gear being configured to convert the rotational movement of the first servo motor into a linear movement, and the second cam gear being configured to convert the rotational movement of the second servo motor into a linear movement,
• at least two pull rods, the at least two pull rods comprising a first pull rod and a second pull rod, the first pull rod being operatively connected to the first cam gear and being configured to be provided with the linear movement so as to drive the ram via the first pressure point group, and the second pull rod being operatively connected to the second cam gear and being configured to be provided with the linear movement so as to drive the ram via the second pressure point group,
• a press bed,
• a bottom die arranged on the press bed,
• a top die operatively connected to the ram,
• a process cushion arranged in at least one of the ram, the press bed, the bottom die, and the top die,
• a force sensor configured to detect an actual force value feedback, and
• a temperature sensor configured to detect an actual temperature value feedback,
• the device comprising:
• an NC control device which is configured to control at least one of a position, a speed and a force of each hydraulic pressure cushion assigned to the pressure points of the ram for a first auxiliary function and the process cushion for a second auxiliary function, the NC control device comprising:
• a positional cam profile which is configured to control at least one of a position, a speed, a torque and a force of the at least two servo motors for driving the pressure points of the ram, the positional cam profile being controlled by a virtual control shaft;
• a sequential control;
• a storage device for machine and die data;
• a first functional unit for calculating pressure point-specific curves of a target force value for each hydraulic pressure cushion of the first auxiliary function;
• a second functional unit for a force control of each hydraulic pressure cushion;
• a third functional unit for calculating cushion-specific curves of a target force value for the process cushion of the second auxiliary function;
• a fourth functional unit for a force control of the process cushion;
• a fifth functional unit for calculating pressure point-specific curves of a target position with initial correction values;
• a sixth functional unit for a position control of the pressure points of the ram as a main function;
• a seventh functional unit for calculating pressure point-specific force correction values, input values for the seventh functional unit being measured signals of the actual force value feedback, and output values of the seventh functional unit when summed together with output values of the first functional unit for calculating the pressure point-specific curves of the target force value determine input values into the second functional unit for the force control of each hydraulic pressure cushion;
• and
• an eighth functional unit for calculating cushion-specific force correction values, input values of the eighth function unit being measured signals of the actual force value feedback and the actual temperature value feedback, and output values of the eighth functional unit when summed together with output values of the third functional unit for calculating the cushion-specific curves of the target force value determine input values into the fourth functional unit for the force control of the process cushion.