Precautions for deep hole machining.

Precautions for deep hole drilling processing

1、The main points of deep hole drilling operation

The coaxially of the spindle and tool guide sleeve, tool holder support sleeve, workpiece support sleeve, etc. should meet the requirements; the cutting fluid system should be smooth and normal; there should be no center-center hole on the processing end face of the workpiece, and avoid drilling on the oblique surface; the chip shape should be kept normal to avoid generating straight ribbon chips; use a higher speed to process through holes, and when the drill is about to drill through, the speed should be reduced or stopped to prevent damage to the drill.

2、Note for using deep hole drill

1) The workpiece end face is perpendicular to the axis of the workpiece to ensure reliable end face sealing.

2) Pre-drill a shallow hole in the workpiece before formal processing to guide the centering role when drilling.

3)To ensure the tool's life, it is better to use automatic tool walking.

4)The guiding elements in the feeder and the movable center-center support should be replaced in time if they are worn out, so as not to affect the accuracy of deep hole drilling.

Maintenance and Inspection of Deep Hole Drilling Tools

Regular maintenance and inspection of deep hole drilling tools are essential to ensure consistent performance. Ground drilling tools, in particular, should be checked frequently for wear and tear. Any signs of dullness or damage to the tool’s cutting edges can advance to inaccuracies or inefficient cutting. Additionally, the tool’s surface should be kept clean and free of any debris that could obstruct its function.

It is crucial to check the cutting fluid system regularly. The fluid not only serves as a coolant but also helps in removing chips from the cutting area. A poorly maintained fluid system can advance to overheating of the tool and workpiece, causing premature tool wear. Ensuring that the fluid pressure and flow are consistent will prevent unnecessary tool damage and reduce the risk of faults during deep hole drilling.

Handling of Chip Formation and Removal

One of the more challenging aspects of deep hole drilling is managing the chips formed during the drilling process. These chips must be effectively removed from the drilling zone to prevent them from interfering with the cutting process. If chips are not removed efficiently, they can cause clogging, overheating, and reduced cutting efficiency.

For deep hole drilling, it’s essential to use tools designed for chip evacuation. The tool should be equipped with appropriate flutes and cutting geometry to ensure chips are evacuated continuously as the hole deepens. Additionally, the type of chips produced should be monitored; ribbon-type chips or long stringy chips can advance to tangling or clogging, while small, fragmented chips are easier to remove and cause less interference.

The guiding elements in deep hole drilling tools, such as the center support and feed mechanism, must be adjusted and maintained regularly to avoid any misalignment. Even slight deviations in tool alignment can advance to significant issues, such as poor hole quality or tool failure.

Choosing the Right Deep Hole Drilling Tool

When selecting a tool for deep hole drilling, it is important to consider the material being drilled, the hole depth, and the precision required. For hard materials, a tool with a robust design and high resistance to wear is necessary. On the other hand, softer materials may allow for a more flexible drilling tool. The ground drilling tool’s geometry should be suited to the specific application, ensuring proper chip removal and ideal cutting efficiency.

Additionally, the tool's material should be compatible with the workpiece to prevent unnecessary wear and prolong the lifespan of both the tool and the machine. In deep hole drilling applications, a tool with a strong cutting edge and durable coating is preferable to ensure that it can withstand the heat and pressure generated during the drilling process.

Deep Hole Drilling in Complex Materials

When working with complex materials, such as composite or hardened alloys, deep hole drilling becomes more intricate. The material’s properties can significantly affect the cutting process, making it more difficult to achieve high-quality results. In these cases, using the right deep hole drilling tool becomes even more crucial. The tool must be capable of managing the additional challenges posed by these materials, including thermal expansion, hardness variations, and the potential for tool wear.

It is advisable to use tools designed specifically for these applications. For example, tools with a coated surface or those made from high-performance alloys can offer increased resistance to material stresses and provide better longevity, even when drilling through tough, difficult-to-machine materials.