Single Flute Gun Drills have the advantage of higher drilling quality. Still, due to lower rigidity and sharpening defects, the processing efficiency is limited, so the achievable supply speed is small. There are problems of low processing efficiency and short tool life. It is worth considering the improvement and optimization of Single Flute Gun Drills to improve its processing efficiency. This article will take you to see the improved methods of single-edged deep-hole exercises.
Single Flute Gun Drills have the advantage of higher drilling quality. Still, due to lower rigidity and sharpening defects, the processing efficiency is limited, so the achievable supply speed is small. There are problems of low processing efficiency and short tool life. It is worth considering the improvement and optimization of single-edged deep hole drills to improve its processing efficiency. This article will take you to see the improved methods of single-edged deep-hole exercises.
Slight cutting edge rounding-overall layer-suitable feed
By optimizing the tool, it is possible to improve processing efficiency and extend tool life while ensuring the quality of the Single Flute Gun Drill. For example, for the processing of stainless steel materials, it is necessary to pay attention to the tool’s design and study different coating materials and coating structures. Many studies have shown that the tool wear of the overall layer is smaller, compared with ordinary partial coatings. Simultaneously, compared with single-edged deep hole drills with sharp cutting edges, slightly rounding the cutting edge can extend Tool life; also, the appropriate feed rate is a significant factor.
The experiment uses ordinary uncoated solid carbide single-edged deep hole drills to process low-sulfur quenched and tempered steel as a comparison benchmark to evaluate single-edged deep hole drills’ performance. Through the cutting test, the tool wear and chip shape of the ordinary solid carbide Single Flute Gun Drill show that under the condition of feed rate f=0.02mm, the tool wears slightly when the drilling length reaches 30m. The cutting head and cutting force load are small, so there is only slight crater wear and flank wear. The generated chips are oblique spiral chips, which are easy to discharge from the hole. By increasing the feed rate, after the drilling length reaches lf=9m, the tool outer circle’s tip has shown severe wear.
From the actual use effect, the ordinary Single Flute Gun Drill can use for deep hole processing. But to improve the processing efficiency, certain conditions must be restricted, and significantly if the feed rate increase, the tool will wear out too quickly. When the feed rate of the single-edge significant hole drill changes, it can be seen that the measured value increases with the increase of the feed rate, which is almost linear. When the feed amount f=0.34mm, the feed force Ff=950N, the torque Mb=4.3Nm; when f=0.36mm, the tool damage due to excessive torsional load. According to the predetermined tool life, the feed rate can increase by ten times. The measurement results show that within the drilling length of 30m because the ordinary Single Flute Gun Drill can reach a drilling length of 30m when the feed rate f=0.02mm, increasing the feed rate will result in a regular single-edge routine. The deep hole drill wears faster, and the single-edged deep hole drill uses a feed rate ten times higher, that is, f=0.2mm, which still reaches the predetermined life index. Scanning electron microscope analysis proves that the tool is still in normal wear and can even use.
Slightly rounded edge
In addition to tool wear, hole quality is also an important indicator that affects deep hole drilling performance. The eccentricity error value of the hole is affected by the tool structure and feed. The measured values of different single-edged deep hole drills are at a comparable level. It shows that the improvement of tool sharpening will not adversely affect the eccentricity of the hole. At the same time, the cutting edge rounding can improve the processing efficiency and make the eccentricity error of the hole reach an acceptable level.
Through the improvement of tool structure and technology, the tool’s processing efficiency and service life can improve effectively. In a word, the improvement in tool structure design, coating, and cutting edge rounding is fruitful, which can realize the efficient machining of single-edge deep-hole drills.