The difference between the full closed loop and semi-closed loop systems of die-casting machines lies mainly in the feedback mechanism, accuracy, cost and maintenance difficulty. ‌

Feedback mechanism

·‌Full closed loop system‌: The full closed loop control system uses measuring elements to detect the actual displacement of the die-casting machine and feeds back this information to the CNC system. This system uses a negative feedback mechanism to form a closed loop with the signal forward path and feedback path, thereby achieving precise control of the system.

·‌Semi-closed loop system‌: The semi-closed loop system installs an angular displacement detection device (such as a photoelectric encoder) on a transmission component such as a servo motor or a lead screw, and indirectly calculates the displacement of the moving component by monitoring the motor's rotation angle or the rotation of the lead screw. This system combines the characteristics of open loop and closed loop, and improves the accuracy of the system through an internal feedback mechanism.

Accuracy

·‌Full closed loop system‌: Since the full closed loop system directly measures the actual displacement and feeds back to the CNC system, it can obtain very high accuracy, which is suitable for application scenarios with extremely high accuracy requirements. ·‌Semi-closed-loop system‌: Although the semi-closed-loop system calculates displacement through indirect measurement, its accuracy is still better than that of the open-loop system, and it is suitable for medium-precision processing tasks.

Cost and maintenance difficulty

·‌Full-closed-loop system‌: Due to the need for high-precision measuring elements and complex installation and debugging processes, the full-closed-loop system is expensive, and the installation and maintenance costs are also relatively high.

·‌Semi-closed-loop system‌: The cost and complexity of the semi-closed-loop system are between the open-loop and the full-closed-loop, which is suitable for most small and medium-sized CNC machine tools. The debugging and maintenance are relatively simple, and the cost is moderate.

Application scenarios

·‌Full-closed-loop system‌: It is suitable for occasions with extremely high precision requirements, such as high-precision mold manufacturing and parts production.

·‌Semi-closed-loop system‌: It is suitable for medium-precision processing tasks, such as mold manufacturing, mass production of parts, etc.

In summary, there are significant differences between full-closed-loop and semi-closed-loop systems in terms of feedback mechanism, accuracy, cost and maintenance difficulty. Users can choose the appropriate system type according to specific needs.