In the precision machining system of CNC gantry drilling machines, the principle of position detection and feedback is the core technical link to ensure the accurate operation of the equipment. This principle captures the real-time position information of the moving parts of the drilling machine and converts it into a processable signal feedback to the control system, forming a closed-loop control to ensure that the drilling position, depth and other parameters meet the machining requirements, which is the key to achieving high-precision machining.
The position detection and feedback system mainly consists of three parts: position detection device, signal processing unit, and control system. As the front-end of information collection, position detection devices need to have high sensitivity and stability. Common types include grating rulers, encoders, etc. Taking the grating ruler as an example, it generates Moir é fringes through the relative movement of the grating pair, and then converts the fringe signal into an electrical signal, thereby achieving accurate measurement of the displacement of moving parts. Encoders are often installed on the motor shaft or ball screw end, indirectly calculating linear displacement by recording the rotation angle. The two devices can be flexibly combined and used according to the machining accuracy requirements and cost budget.
In the specific process of detection and feedback, when the CNC system issues a motion command, the servo motor of the drilling machine drives the ball screw to drive the worktable or spindle to move. At this point, the position detection device synchronously collects the actual position data of the moving parts and transmits analog or digital signals to the signal processing unit. The processing unit filters, amplifies, and converts the original signal, eliminates interference signals, and transmits standardized position information to the control system. The control system compares and analyzes the actual position with the commanded position. If there is a deviation, it immediately generates a compensation signal to adjust the operating parameters of the servo motor and correct the motion trajectory until the deviation between the actual position and the commanded position is controlled within the allowable range.
This closed-loop feedback mechanism runs through the entire machining process and can real-time correct position errors caused by factors such as mechanical clearance, load changes, temperature drift, etc. For example, in long-term continuous drilling operations, thermal deformation of mechanical components may cause positional displacement, and the position detection and feedback system can quickly capture this change. By dynamically compensating the control system, the machining accuracy of the drilling machine can be maintained stable. It is precisely through this precise detection and rapid feedback adjustment that CNC gantry drilling machines can achieve efficient and high-precision drilling operations in the processing of large plates and heavy components, meeting the stringent processing requirements for key components in fields such as aerospace and engineering machinery.