The present invention relates to a press control method for increasing the performance of a mechanical press with a hybrid mechanism used in processes such as forming, bending, punching, cutting, and drawing.

Background of the Invention

Presses, which are among the primary industrial machines today, are generally examined in two main groups. These are hydraulic presses and mechanical presses. Mechanical presses operate with the principle of transferring the kinetic energy accumulated by means of rotation of the flywheel onto the ram as force by a mechanism. Today, servo motor replaces the flywheel, and such presses are called servo motor controlled presses (servo press). In the state of the art, servo motor curves are not distributed equally on the operating area. It reaches excessive torque/speed in one area, while torque/speed values remain low in another area. Therefore, the press cannot be accelerated as much as required. Since there is no die weight recognition and load entry point detection method in the press control methods used in the state of the art, the operation of the press is left to the operator's knowledge.

Patent application no 2011/09163, known in the state of the art, discloses a servo mechanical press system with a hybrid mechanism. The press system comprises a frame, at least one cavity inside the frame, at least one flywheel which provides the mechanical energy required for the system, at least one motor which enables the flywheel to rotate, at least one upper mechanism which operates with the mechanical energy stored by the flywheel, at least one servo motor which converts the electric energy into mechanical energy, at least one lower mechanism which operates with the mechanical energy generated by the servo motor. The energy used in the invention of the application cannot be evenly distributed within the mechanism, and more energy is used in the press system and it not achieved sufficient performance. For this reason, the production rate decreases.

The Problems Solved with the Invention

The objective of the present invention is to provide a press control method for the press with hybrid mechanism to use the energy more efficiently.

The objective of the present invention is to provide a press control method for a press system which increases production rate in dies used for processes such as forming, bending, punching, cutting, and drawing.

Detailed Description of the Invention

A press control method preferably for more efficient operation of the servo mechanical press comprises the steps of - resetting the pressure of the pneumatic cylinders, torque measurement module making torque measurement through the crank link of the servo motor at certain points, calculating module calculating the die weight according to the torque values, calculating module calculating and applying the suitable pneumatic pressure according to the calculated die weight, recording information such as values of links of the servo hybrid mechanical press, servo motor torque and speed, product length limit, etc. into a database, product length measurement module determining the height of the product by means of dynamic calculation at the point at which the torque of the servo motor increases during the learning strokes, controller determining at least one control point according to the stroke, product length, upper dwell values, the controller calculating the value of shifting the servo motor motion profile so as to provide maximum spm (strokes per minute) or minimum torque according to the information received from the torque measurement module, calculation module, product length measurement module.

The smart press control method of the present invention relates to a control method which enables to increase the performance of the servo hybrid mechanical press. The servo-mechanical press system with hybrid mechanism comprises a flywheel, a motor which enables the flywheel to be rotated and which is connected to the flywheel, an upper mechanism which operates with the mechanical energy generated by the flywheel, a servo motor which converts the electric energy into mechanical energy, and a lower mechanism which operates with the mechanical energy generated by the servo motor.

In the control method, first it is required to determine the die weight of the press. Pneumatic balancing cylinder pressures are reset or fixed at a determined level. The torque measurement module performs torque measurement at certain angles of the crank link of the servo motor. Then, the calculation module calculates the die weight from the kinetostatic. In this calculation, mass will be determined by comparing the force analysis performed with the ram without die in the static condition and the force analysis results in the state with the die.

The link values of the servo hybrid mechanical press, inertial values, pneumatic cylinder diameter, expansion tank volumes, maximum product length, maximum and minimum stroke height, servo motor torque and speed value, maximum torque and speed of constant velocity motor of flywheel, transfer ratio of the servo motor, reference force value of the servo motor are recorded in the database.

In order to determine the length of the product, the motion profile relative to the maximum part length will be determined and the first stroke will be made. The product length measurement module determines the height of the product by comparing the torque value corresponding to the specific height in the servo torque value motion profile with the T _ref value. If the torque value corresponding to the specific height in the servo torque value motion profile is lower than the T _ref value, the height value will be decreased and the most suitable height value will be determined by continuing the trials until the T _ref value is achieved.

The controller determines more than one control point on the movement axis after determining the stroke height, product length, and upper dwell values.

The controller calculates the maximum spm with optimum shifting value to minimize the maximum torque value or maximizes upper dwell value. Offsetting fall and rise zones to the right or left along the master axis, provided that the profile of the motion profile during forming remains fixed, is called shifting. The purpose here is to change the top dead center in the final motion profile of the ram, thereby balancing the torques in the rise and fall zones. Maximum torque value is minimized according to the shifting value determined by the controller. This calculation is made considering the limits given depending on the servo motor characteristics, changing the shifting angle and using multi-objective genetic algorithm, and the ideal one will be selected among the possible solutions.

An example of the genetic algorithm method used here is the NSGA-II algorithm, which creates a Pareto-optimal set comprised of solutions that do not suppress each other to be able to observe the changes between the objectives and offer alternatives for evaluating different situations in multi-objective problems.