1. Using a CNC deep hole drilling machine to process deep holes, a stable equipment structure, good shock absorption performance, and minimal axial runout are necessary to ensure the machining accuracy, repeated positioning accuracy, and surface roughness of deep holes;

2. The appropriate geometric shape of the drill bit in a CNC deep hole drilling machine can make deep hole machining more efficient;

3. The Caixiang through axis high-pressure cooling system can smoothly remove chips, increase spindle speed and feed rate, and extend tool life.

4. The axial cooling, precise geometric shape of the drill bit, alloy cutting tools, and reasonable selection of cutting parameters are important influencing factors in deep hole machining. Each factor will affect the dimensional accuracy, surface roughness, machining cycle, and tool life of the hole.

Summary: A preferred combination of CNC deep hole drilling machine technology is to use a high-pressure cooling system, an open drilling groove, coated alloy cutting tools, and only require a single tool retraction to complete. The above conditions are the basic requirements for successfully achieving deep hole machining on a CNC deep hole drilling machine.

1、 Advantages of high-pressure cooling technology

To effectively apply coolant in modern machining, it is necessary to use more high-pressure jet cooling and ensure that its flow rate is large enough and the jet direction is correct. High pressure cooling has more obvious advantages than conventional cooling methods in many aspects, including chip formation, cutting heat distribution, surface integrity, tool wear, and excellent anti bonding properties on workpiece materials and cutting edges.

1. Cooling effect

High pressure cooling technology uses high-pressure coolant to accurately and sufficiently spray directly into the cutting area (heat affected zone) between the front cutting surface of the blade and the chips, thereby maximizing the removal of heat from the cutting area and allowing the coolant to perform at its best, achieving rapid cooling.

2. Chip control ability

The use of high-pressure cooling effectively reduces the cutting heat in the cutting area, increases the brittleness of the chips, makes them easy to break, and thus obtains short chips, so that the chips are no longer entangled. The distribution of coolant pressure and the size of the nozzle can have a significant impact on iron filings. By adjusting the jet parameters, different chip rolling effects can be obtained to improve chip length. At the same time, due to the formation of a high-pressure water wedge in the cutting area, it is also possible to forcefully break the chips. Thereby reducing the impact of chips on the machining effect.

3. Tool life

After adopting high-pressure cooling method, the distance between the coolant nozzle and the cutting edge of the blade is closer, and the coolant can accurately reach the cutting area between the front cutting surface of the blade and the chips, achieving better chip control and cooling effect on the cutting edge, thereby reducing tool wear and extending tool life. In general, increasing the cutting speed can lead to a reduction in tool life, but with the use of high-pressure cooling and an increase in feed rate, the reduction in tool life is not as significant.

4. Competitiveness

The high-pressure cooling method can better control chips, effectively cool down, achieve non-stop operation, shorten the machining cycle, make the machining process safer and more reliable, prolong the tool life, improve the surface quality of parts, improve machining efficiency and quality, and reduce machining costs. Further enhance the comprehensive competitiveness of enterprises.

The so-called high-pressure cooling technology refers to the process of raising the pressure of the coolant to a specific level, passing through internal coolant channels and nozzles, and accurately spraying it into the desired cooling area, thereby achieving rapid cooling. High pressure cooling (HPC) has shown good performance in general processing applications, especially in the processing of stainless steel and low carbon steel. It also performs well in the processing of difficult to machine materials such as aerospace materials such as titanium alloys and heat-resistant superalloys. Compared to high-pressure cooling, traditional cooling involves the use of coolant to fill the cutting area; The coolant should not be sprayed between the chip and the blade, and should effectively cool the hottest zone of the blade; Wide heat affects the contact area. The high-speed jet of high-pressure coolant forms a hydraulic wedge, providing more effective cooling of the blade near the thermal contact zone (Figure A below). Forcing chips to quickly leave the cutting surface reduces blade wear (as shown in Figure B), which helps to split the chips into small pieces and discharge them from the cutting area.

2、 High pressure cooling application

1. Application of High Pressure Cooling Technology in Turning

High pressure cooling tools create a barrier between the blade edge and the chips through high pressure and accurate orientation, creating a hydraulic wedge between the blade and chips, affecting chip formation and flow, and reducing the temperature of the cutting area. The nozzle installed near the cutting edge accurately sprays a high-speed coolant jet, forcing the chips to leave the blade surface and cooling and breaking them, facilitating chip removal.

Even with a coolant pressure as low as 10 Pa, using high-pressure cooling technology for precision machining of materials such as steel, stainless steel, aluminum alloys, titanium alloys, and high-temperature alloys can yield significant benefits. In addition to higher machining safety brought by better chip control, high-pressure cooling can significantly extend tool life (up to 50%); The potential brought by adopting higher cutting speeds is significant cost savings in production.

Compared to any other factor, cutting speed has a greater impact on cutting temperature and tool wear. When processing titanium alloys beyond the reasonable processing area, increasing the cutting speed can lead to a sharp reduction in tool life, but increasing the feed rate in a similar way does not result in such a significant reduction in tool life. Therefore, changing the feed rate to improve the metal removal rate has become a more attractive solution. However, using a high feed rate is not always a foolproof solution. An increase in feed rate will definitely generate greater cutting force and also affect chip control.

With higher cutting speeds but without the common temperature rise and reduced tool life, high-pressure cooling technology has the potential to improve machining performance. For ISOS materials, when the cutting speed is increased by 20%, the cutting length can still remain the same.

Internal turning is also an area where high-pressure cooling technology can play an important role, helping to ensure good chip formation and improve the shear performance of difficult to machine materials such as titanium alloys. In this way, higher machining safety and longer tool life can be achieved during the boring process.

2. Application of High Pressure Cooling Technology in Milling

High pressure cooling technology also brings benefits to milling. High pressure accurate positioning creates a partition between the cutting edge and chips, reducing the temperature in the cutting area, thereby extending tool life, improving cutting efficiency, enhancing chip control, and meeting customer quality requirements.

High pressure cooling processing should not be seen as a means of remedying the drawbacks caused by other application factors such as unsuitable blades, instability, and incorrect cutting parameters. This technology is the 'optimizer' when the process settings are basically correct. This concept provides a solution for achieving shorter machining time, improving part quality consistency, and higher machining safety in turning and milling.

The demand for optimizing various machining processes, especially when chip formation and processing of difficult to machine materials dominate, makes high-pressure cooling technology, which can be widely applied on machine tools, undoubtedly an attractive choice. The increasing popularity of multitasking machine tools and the new generation of vertical lathes has highlighted the benefits of using high-pressure cooling for machining, especially from the perspective of chip control.