Advantages of U drill:
1. First of all, the difference between U drill and ordinary drill is that U drill uses blade peripheral blade and center blade. From this perspective, the relationship between U drill and ordinary hard drill is actually similar to that between machine clamp turning tool and welding turning tool. After the tool is worn, there is no need to re-grind the blade and directly replace the blade. After all, using indexable blades is more material-saving than integral hard drill, and the consistency of the blade makes it easier to control the size of parts.
2. U drill has better rigidity and can adopt a very high feed rate. Moreover, the processing diameter of U drill is much larger than that of ordinary drill, and the maximum can reach D50~60mm. Of course, U drill cannot be made too small due to the characteristics of blade installation.
3. U drill only needs to replace the blades of the same type and different brands when encountering various materials, while hard drill is not so convenient.
4. Compared with hard drill, the hole precision of U drill is still higher, and the finish is better, especially when the cooling and lubrication are not smooth, it is more obvious, and U drill can correct the position accuracy of the hole, which is not the case with hard drill. U drill can be regarded as a heart-passing bore cutter.
Advantages of U drill in CNC machining:
1. U drill can drill holes on surfaces with an inclination angle less than 30° without reducing cutting parameters.
2. After the cutting parameters of U drill are reduced by 30%, intermittent cutting can be achieved, such as machining intersecting holes, intersecting holes, and interpenetrating holes.
3. U drill can drill multi-step holes, and can bore holes, chamfer holes, and eccentric holes.
4. When drilling with U drill, the drill chips are mostly short chips, and its internal cooling system can be used for safe chip removal. There is no need to clean the chips on the tool, which is beneficial to the processing continuity of the product, shorten the processing time, and improve efficiency. 5. Under the standard aspect ratio, there is no need to remove chips when drilling with U drill.
6. U drill is an indexable tool. The blade does not need to be sharpened after wear. It is convenient to replace and the cost is low.
7. The surface roughness value of the hole processed by U drill is small, the tolerance range is small, and it can replace the work of some boring tools.
8. When using U drill, there is no need to pre-drill the center hole. The bottom surface of the processed blind hole is relatively straight, eliminating the need for a flat-bottom drill bit.
9. The use of U drill technology can not only reduce the number of drilling tools, but also because the U drill uses a carbide blade in the head, its cutting life is more than ten times that of an ordinary drill bit. At the same time, there are four cutting edges on the blade, and the blade can be replaced at any time when it is worn. The new cutting saves a lot of grinding and tool replacement time, and can improve work efficiency by an average of 6-7 times.
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U drill usage tips on CNC machine tools
1. When using U drill, the rigidity of the machine tool and the centering of the tool and the workpiece are required to be high. Therefore, U drill is suitable for use on high-power, high-rigidity, and high-speed CNC machine tools.
2. When using U drill, the center blade should be a blade with good toughness, and the peripheral blades should be sharper.
3. When processing different materials, blades with different grooves should be selected. Generally, when the feed rate is small, the tolerance is small, and the length-to-diameter ratio of the U drill is large, a grooved blade with smaller cutting force should be selected. On the contrary, when the U drill is rough, the tolerance is large, and the length-to-diameter ratio is small, a grooved blade with larger cutting force should be selected.
4. When using a U drill, you must consider the spindle power of the machine tool, the stability of the U drill clamping, the pressure and flow of the cutting fluid, and control the chip removal effect of the U drill. Otherwise, the surface roughness and dimensional accuracy of the hole will be greatly affected.
5. When clamping the U drill, the center of the U drill must coincide with the center of the workpiece and be perpendicular to the workpiece surface.
6. When using the U drill, select appropriate cutting parameters according to different part materials.
7. When cutting with a U drill, do not reduce the feed rate or speed arbitrarily due to fear, which may cause the U drill blade to break or the U drill to be damaged.
8. When using a U drill for processing, if the blade is worn or damaged, carefully analyze the cause and replace it with a blade with better toughness or more wear resistance.
9. When using a U drill to process stepped holes, be sure to start with the large hole first and then the small hole. 10. When using a U drill, make sure that the cutting fluid has enough pressure to flush out the chips.
11. The blades used for the center and edge of the U drill are different. Do not use them incorrectly, otherwise the U drill shank will be damaged.
12. When using a U drill to drill holes, you can use the workpiece rotation, tool rotation, and simultaneous rotation of the tool and workpiece. However, when the tool moves in a linear feed mode, the most common method is to use the workpiece rotation method.
13. When processing on a CNC lathe, consider the performance of the lathe and make appropriate adjustments to the cutting parameters, generally by reducing the speed and feed.
Common problems with U drills in CNC processing:
1. The blade is damaged too quickly and is easy to break, increasing the processing cost.
2. A harsh whistling sound is emitted during processing, and the cutting state is abnormal.
3. The machine tool shakes, affecting the processing accuracy of the machine tool.
Points to note when using U drills:
1. When installing U drills, pay attention to the positive and negative directions, which blade is facing up, which blade is facing down, which face is facing inward, and which face is facing outward.
2. The center height of the U drill must be corrected. The control range is required according to its diameter size, which is generally controlled within 0.1mm. The smaller the diameter of the U drill, the higher the center height requirement. If the center height is not good, the two sides of the U drill will wear, the hole diameter will be too large, and the blade life will be shortened. Small U drills are easy to break.
3. U drills have high requirements for coolant. It must be ensured that the coolant is ejected from the center of the U drill. The greater the pressure of the coolant, the better. The excess water outlet of the turret can be blocked to ensure its pressure.
4. The cutting parameters of the U drill are strictly in accordance with the manufacturer's instructions, but different brands of blades and the power of the machine tool must also be considered. During processing, the load value of the machine tool can be referred to and appropriate adjustments can be made. Generally, high speed and low feed are used.
5. The blades of the U drill should be checked frequently and replaced in time. Different blades cannot be installed in reverse.
6. Adjust the feed amount according to the hardness of the workpiece and the length of the tool overhang. The harder the workpiece, the greater the tool overhang, and the smaller the feed amount should be.
7. Do not use excessively worn blades. The relationship between blade wear and the number of workpieces that can be processed should be recorded during production, and new blades should be replaced in time.
8. Use sufficient internal coolant with the correct pressure. The main function of coolant is chip removal and cooling.
9. U drills cannot be used to process softer materials such as copper, soft aluminum, etc.
