What no-load tests need to be considered when debugging deep hole drilling rigs?

The no-load test during the debugging phase of the deep hole drilling rig is the core link to verify equipment performance, eliminate assembly and design defects, and ensure the stability of subsequent load processing. It needs to cover full system functional verification to avoid hidden faults that may cause accidents or scrap during actual processing. The no-load test needs to be carried out around the four major modules of the main engine, power system, control unit and auxiliary functions, taking into account the performance of the single machine and the coordination of system linkage.

It is a no-load test of the host core system, which is a basic verification item. The spindle system needs to be tested first: start the spindle, switch between low, medium and high speeds within the rated speed range, perform forward and reverse rotation respectively, monitor the spindle operating status - whether there is abnormal vibration or noise, whether the tachometer display matches the set value, and use a dial indicator to detect the spindle radial and end face runout to confirm whether it meets the design accuracy requirements. Next is the no-load test of the feed mechanism: the drive slide moves repeatedly along the guide rail throughout the entire stroke to observe whether the feed action is smooth and whether there is any stuck or crawling phenomenon; test the stepless adjustment or gear switching function of the feed speed to confirm that the feed command responds promptly and without lag at different speeds; at the same time, check the lubrication effect of the guide rail pair. After 30 minutes of no-load operation, there are no dry wear marks on the guide rail surface and the oil film is uniform.

The second step is the no-load test of the hydraulic and pneumatic power systems. The feeding, workpiece clamping and other actions of the deep-hole drilling rig mostly rely on hydraulic drive, and the pressure stability needs to be verified under no-load conditions. Start the hydraulic station to run without load for 15 minutes, and monitor whether the system pressure is stable within the rated range, whether there are external leaks in each valve group and pipeline, and whether the oil temperature rise is within a reasonable range (generally, the oil temperature does not exceed 50°C after no-load operation). Then test the linkage of the actuator: simulate the process of workpiece clamping, feed start, and spindle operation, and confirm that the interlocking logic of "the spindle can start only after the clamping is in place" is normal and there is no action conflict. If it has a pneumatic auxiliary function, the pressure and flow stability of the pneumatic system need to be tested to ensure that each pneumatic valve operates sensitively and has no air leakage.

The no-load test of the electrical and control system is the key to intelligent operation. Function-by-function verification is required for CNC deep-hole drilling rigs: input commands such as spindle start and stop, speed adjustment, etc., to confirm that there is no command delay or incorrect execution in the CNC system; test safety interlocking functions, such as the spindle automatically stopping when the protective door is opened, and the feed limit triggering an emergency stop when overtraveling, to verify the accurate feedback of the sensor signal; simulate the overload triggering mechanism to confirm that the electrical protection system (overload protection of the spindle and feed motor) can respond normally to avoid motor burnout under load.

It is a no-load test of auxiliary functions. Deep hole drilling requires extremely high cooling and chip removal. It needs to be verified in advance under no load: start the cooling pump, adjust the coolant pressure and flow rate, and check that the nozzle is unobstructed and there is no uneven flow caused by clogging; test the chip removal mechanism without load to observe whether the chip removal chain and spiral chip conveyor are stuck, and there are no foreign objects blocking the chip removal path; in addition, simulate tool clamping to confirm that the spindle taper hole is clean, and the tool holder is clamped firmly without looseness to avoid the tool falling off during actual processing.

The no-load test needs to be carried out in stages: first, single-machine no-load debugging of each system, and then joint debugging. It is recommended that the continuous operation time be no less than 2 hours. All test data should be recorded throughout the process to provide a benchmark basis for subsequent load debugging and ensure that the equipment ultimately meets the processing accuracy and stability requirements.