Injection Molding Electro-hydraulic Servo System Technology and Application (4)

Selection and Configuration Method <br> When the maximum required flow rate of the injection molding machine and the highest system pressure are known, the following methods can be used in the oil pump/motor/driver series.
First: According to the maximum flow of demand, calculate the theoretical pump displacement demand.
Theoretical demand displacement = maximum flow * 1000 / maximum speed Displacement unit: ml / rev, flow unit: l / min, speed unit: rev / min, the maximum speed to take the motor and the pump's maximum speed in the smaller value. In the oil pump series, select the oil pump that has a larger displacement and is closest to the theoretical required displacement.
Second: Calculate the theoretical demand torque of the motor and select the motor from the displacement of the oil pump and the maximum working pressure of the system.
Theoretical demand torque = (pressure * displacement * 9.55) / mechanical efficiency value * 60
Moment unit: Newton, pressure unit: MPa, value of mechanical efficiency 1.
Select a motor with a nominal torque in the motor similar to the theoretical demand torque/2.
Third: Select the servo controller by the maximum current

Maximum Current = Rated Current * Maximum Pressure / Continuous Operating Pressure Current Unit: Ampere. Select the controller with peak current greater than and closest to the desired maximum current in the servo controller.
The above matching method follows the principle of double torque overload. The running time of general torque twice overload is 20 seconds, and the running time of triple overload is 5 seconds. The torque corresponding to 30 seconds, 20 seconds and 10 seconds can be calculated according to the proportion. Overload multiplier.
Development direction <br> Servo electro-hydraulic mixing system: In addition to using a servo motor to provide the total power for the injection molding machine, it is also possible to flexibly use a single motor to drive the specified hydraulic components, or use several servo motors to realize the combined drive.
Servo electro-hydraulic system with position sensor: Through the position sensor of the screw travel cylinder, the speed and position of the shot can be controlled more precisely. The qualification rate, quality and accuracy of the trial product will be further improved.
The servo electro-hydraulic system that incorporates the plastic molding process technology: In cooperation with the host computer, the injection molding process technology is matched with the hydraulic power system, and it is expected that a product combining the molding process technology and the servo control technology can be expected to meet the needs of high-end customers.
Multi-pump confluent servo electro-hydraulic system: Through the CAN bus bar technology, several servo electro-hydraulic pumps are connected to form a multi-pump confluence control to achieve large-scale injection molding machine hydraulic control, optimize system efficiency, and increase system life. (Finish)