What performance indicators need to be considered when accepting deep hole drilling rigs?

The deep hole drilling rig is the core equipment for realizing large-depth and high-precision hole processing. Its acceptance process directly determines whether the equipment can meet production needs. Multi-dimensional verification needs to be carried out around core performance indicators, as follows:

It is an accuracy index, divided into two parts: geometric accuracy and machining accuracy, and is the basis of hole processing quality. The acceptance of geometric accuracy requires the detection of the radial runout of the spindle end (usually required to be ≤0.005mm), the axial movement (≤0.002mm), the straightness and levelness of the bed guide rail, the parallelism and verticality of the spindle box and the worktable. These errors will be directly transmitted to the processed holes. Excessive tolerances will lead to hole shape distortion and positional accuracy inaccuracy. The machining accuracy needs to be verified through actual test drilling: select samples consistent with the material and specifications of the production workpiece, drill deep holes of different depths and diameters, and detect the hole's dimensional accuracy (such as IT7~IT10 level), cylindricity, coaxiality and surface roughness. For example, for deep holes with common aspect ratios, the cylindricity needs to be controlled to not exceed 0.02mm per 1000mm length, and the surface roughness Ra should not be greater than 1.6μm to ensure that it meets the requirements of the processing drawings.

The second is the drilling capability index, and the core is the actual processing parameters and stability. During acceptance, it is necessary to verify the actual accessibility of the rated drilling diameter range and drilling depth, such as test drilling holes of the specified specifications to observe whether there are problems such as poor chip removal and excessive tool wear; at the same time, test the suitability of the drilling torque and spindle speed: for high-strength steel and alloy materials, the main spindle speed needs to be verified. Whether the shaft torque meets the cutting needs, and there will be no boredom or lack of power; the adjustment range and stability of the feed speed are also critical. There should be no creeping phenomenon during low-speed feed and no movement during high-speed feed to avoid hole axis deflection. The feed gears adapted to different processing conditions must all work properly.

The third is the rigidity and stability indicators, which are the core characteristic requirements of deep hole processing. The aspect ratio of deep holes is large and insufficient rigidity will lead to processing vibration and axis deviation. During acceptance, the stiffness of the spindle and the machine bed is tested through static loading, and the deformation under cutting force is measured to ensure that the deformation is within the allowable range; during the dynamic test, holes of different depths are continuously drilled to detect the noise of the whole machine (normal operating noise should be ≤85dB) and vibration, and there is no obvious periodic abnormal sound; at the same time, the wear resistance of the guide rail is verified, and the accuracy loss of the guide rail after continuous operation does not exceed the allowable value, and the stability of long-term processing is verified.

The fourth is the system supporting and performance indicators, including cooling and chip removal, power, and CNC systems (if applicable). The cooling system needs to test the pressure and flow of high-pressure internal cooling to ensure that it can effectively cool the tool and flush out chips. Insufficient pressure will aggravate tool wear and cause chip blockage; the chip removal system needs to verify the ability to discharge long chips and chips in deep holes without stuck accumulation; the power system needs to run continuously for 4 to 8 hours to detect the temperature of the motor and hydraulic system, and there is no overheating or pressure fluctuation; the CNC system needs to test the stability of the program operation, the convenience of parameter modification, and the absence of frequent alarms, crashes and other faults.

It is an indicator of operation and safety. The operation interface must be clear and intuitive, and parameter setting and status monitoring must be convenient. Safety devices such as emergency stop buttons, protective door interlocks, and overload protection must be effective. The spindle cannot be started when the protective door is not closed. Feeding automatically stops when the cutting force exceeds the limit to ensure the safety of the equipment and operators.

During acceptance, it is necessary to combine actual production needs and combine theoretical indicators with trial processing data to avoid judging the equipment's qualification based solely on parameter reports and ensure that the equipment meets the requirements for long-term stable production.