Technical Guide for Standardized Operation of Radial Drilling Machines

As the core hole processing equipment in the mechanical processing workshop, the operation standardization of the radial drilling machine directly determines the processing accuracy, production efficiency and service life of the equipment. Unlike ordinary small drilling machines, radial drilling machines are equipped with multi-degree-of-freedom motion mechanisms and a large stroke processing range. If the operation process is not standardized, it is very likely to cause workpiece displacement, drill bit breakage, wear of equipment components, and even personal safety accidents. This article, combining industry general safety standards with first-hand practical experience, systematically sorts out the key points of the full-process operation technology of the radial drilling machine from four dimensions: pre-operation preparation, standardized operation procedures, operation skills under typical working conditions, and daily equipment maintenance and operation, providing practical operation references that can be put into practice for operators of different experience levels.

Ⅰ. Systematic preparatory work before assignment

The preparatory work before operation is the core prerequisite for avoiding over 90% of potential safety hazards and processing errors. It needs to be implemented item by item from three dimensions: personnel protection, equipment inspection, and working condition confirmation. In terms of personnel protection, operators must wear work clothes with tight cuffs, fully tuck their long hair into the work cap. Throughout the operation, it is strictly prohibited to wear gloves, scarves, rings or other items that can be easily caught in rotating parts. Anti-splash safety glasses must be worn throughout the operation to prevent high-speed flying iron filings from scratching the eyes. It is strictly prohibited to operate the machine when fatigued or drunk. When multiple people work collaboratively, the main operator must be clearly identified. It is forbidden for multiple people to control the equipment handle simultaneously. At the equipment inspection level, a full machine status check must be completed before starting up: Firstly, check that the power line is undamaged, the grounding device is reliable, the oil level of the hydraulic system is within the range of the scale line, and the oil quantity in the oil storage part of the lubrication system is sufficient. Then, wipe the rocker arm guide rail and the surface of the column clean, add a thin layer of lubricating oil, move the spindle box back and forth twice throughout the journey, and confirm that there is no jamming or abnormal noise during the movement. Check the flexibility of each operation handle and locking mechanism. Manually rotate the main shaft in the idle gear position to verify that the speed change mechanism is not stuck. Finally, confirm that there are no obstacles within the swing range of the rocker arm and no irrelevant personnel staying around. After pressing the emergency stop button, the power circuit can be normally cut off. At the working condition confirmation level, operators need to familiarize themselves with the hole position accuracy, hole diameter tolerance and depth requirements of the processing drawings in advance, prepare the corresponding specifications of drill bits, clamping tools, measuring tools and suitable coolant, clear the debris on the worktable in advance, and place the workpieces to be processed and the tooling fixtures in a safe area to avoid occupying the movement space of the rocker arm.

Ⅱ, standardize the full-process operation norms

After completing all the preparatory work, the closed-loop process operation of "trial run - clamping - tool setting - processing - finishing" must be strictly followed, and clear verification nodes should be set for each step. The first step is the no-load test run of the equipment. After connecting the power supply, start the spindle and let the equipment idle at the lowest speed for 3 to 5 minutes. Observe whether the spindle runs smoothly, the lifting action of the rocker arm, and the response of the hydraulic clamping mechanism are normal. After confirming that all components are normal, select the appropriate spindle speed and feed rate based on the processing material and the size of the hole diameter. When processing large hole diameters of steel, choose the low speed gear; when processing small hole diameters of non-ferrous metals, choose the high speed gear. It is strictly prohibited to switch speed gears during the operation of the equipment to avoid damaging the internal gears of the gearbox. The second step is workpiece clamping, which is the core link to prevent processing accidents. All workpieces must be firmly clamped onto the worktable with vise, special fixtures or clamping irons. It is strictly prohibited to hold the workpieces directly by hand for drilling. For thin plate workpieces, solid wood pads must be placed below to prevent drilling damage to the worktable surface. At the same time, a low feed rate should be adopted to prevent the thin plate from shaking and shifting. For large and irregular-shaped workpieces, additional auxiliary supports need to be installed. Only after confirming that the workpiece is completely fixed and there is no shaking when gently pushed by hand can the next step of operation be carried out. The third step is tool setting and positioning. First, loosen the locking mechanism between the rocker arm and the spindle box. According to the hole positions marked on the drawing, move the rocker arm, rotate the column, and slide the spindle box to ensure that the drill bit tip precisely aligns with the sample punch holes on the workpiece. After completing the positioning, lock the locking devices of the spindle box, rocker arm, and column in sequence. Once all locking handles are in place, slightly tap the spindle. Verify the coaxiality of the drill bit and the hole position to avoid hole position deviation in subsequent processing. The fourth step is the formal drilling process. After starting the spindle, let the drill bit idle to stabilize first, then slowly and manually feed to allow the tip of the drill bit to touch the surface of the workpiece. After confirming that the centering is accurate, switch to motorized feed. During the initial stage of drilling and when the hole is about to be drilled through, it is necessary to switch to manual low-force feed to prevent the drill bit from breaking due to sudden force changes and to avoid the workpiece being thrown out along with the rotation of the drill bit. When performing deep hole drilling operations, the drill bit is actively withdrawn for chip removal every time a certain depth is fed in to prevent long iron chips from entangling the drill bit and blocking the chip removal groove. At the same time, coolant is continuously sprayed onto the cutting edge of the drill bit to reduce the cutting temperature and extend the tool life. The fifth step is the finishing operation after processing is completed. When the drilling depth meets the requirements of the drawing, stop the feed first, lift the drill bit completely off the workpiece surface, then turn off the spindle power. Only after the spindle has completely stopped rotating can the workpiece fixture be released to remove the part. Then lower the rocker arm to the lowest position, move the spindle box to a position close to the column, lock all mechanisms, and finally cut off the main power supply of the equipment. Clean the iron filings and oil stains on the surface of the worktable and guide rails. Use a special iron hook and brush to remove the remaining iron filings. It is strictly forbidden to blow on the iron filings with your mouth or wipe them directly with your hands.

Ⅲ. Practical Optimization Techniques for Typical Working Conditions: By applying targeted operation techniques on the basis of standard procedures for different special processing scenarios, the quality and efficiency of processing can be significantly enhanced. In the tapping operation scenario, the spindle speed should be reduced to a low-speed range of less than 30r/min in advance. A floating tapping chuck should be selected to compensate for the coaxiality error. During the tapping process, the tap should be slightly rotated to break the chips every 1 to 2 turns to prevent the iron chips from getting stuck in the tap and causing it to break. At the same time, special tapping lubricating oil should be added to improve the quality of thread forming. In the scenario of batch processing of large flange plates with multiple holes, the reference positioning lines of the flanges can be marked in advance on the worktable. After clamping the workpiece once, the rotary characteristics of the swing arm can be utilized to complete the processing of all circular holes in sequence. There is no need to repeatedly hoist and shift the workpiece. The processing efficiency is more than twice that of the traditional vertical drilling machine, while ensuring that the positional deviation of all holes is controlled within 0.1mm. In the scenario of drilling on an inclined surface, a small plane must first be machined on the inclined surface as the centering reference, or a special V-shaped block should be used to level the workpiece to ensure that the axis of the drill bit is completely perpendicular to the processing plane. It is strictly prohibited to drill directly on the inclined surface to prevent the drill bit from breaking due to force on one side and severe deviation of the hole position. In case of sudden power outages, abnormal equipment noises or other abnormal working conditions, press the emergency stop button immediately to cut off the main power supply. If the drill bit is stuck inside the workpiece, do not force the equipment to start. Instead, manually rotate the chuck at the rear end of the spindle to slowly withdraw the drill bit from the workpiece. Then, check the cause of the fault. Only after completely eliminating the hidden danger can the machine be restarted for operation.

Ⅳ. Common Taboos and Maintenance Points during Operation Long-term practical experience shows that many equipment failures and safety accidents result from habitual violations of operating procedures. Several high-risk operation behaviors must be strictly avoided: It is strictly prohibited to adjust the position of the rocker arm, change the drill bit, or measure the workpiece while the main shaft is running. It is strictly prohibited to use the side of the drill bit as the cutting edge to scrape the workpiece. It is strictly prohibited to wipe the rotating main shaft and drill bit with cotton yarn or towels. It is strictly prohibited to leave the operating post without permission during the operation of the equipment. Completing simple maintenance work simultaneously during daily operations can significantly extend the service life of the equipment: clean the iron filings on the guide rail surface after each operation, check whether the oil pressure of the hydraulic system is stable once a week, and check the radial movement of the main shaft once every half a month. If the bearing wear exceeds the tolerance, adjust it in time. A first-level maintenance should be completed every 600 hours of operation. Clean the oil lines and oil felt, replace the deteriorated coolant, and check the reliability of all limit switches and grounding wires to ensure that the equipment is always in the best operating condition.