1.U drill first of all with the ordinary drill is the difference between the U drill blade peripheral blade and the center blade, in this perspective, U drill and ordinary hard drilling relationship with the clamping lathe and welding lathe relationship is almost the same, the tool wear and no need to regrind directly replace the blade can be. After all, the use of indexable inserts than the whole hard drill to save material, and the consistency of the inserts easier to control the size of the parts.
2. The rigidity of U-drill is better, it can adopt high feed rate, and the processing diameter of U-drill is much larger than ordinary drill, the maximum can reach D50~60mm, of course, U-drill can’t be made too small due to the characteristics of the mounted inserts.
3. U-drill encountered a variety of materials only need to replace the same type of different grades of inserts can be, hard drilling is not so convenient.
4. Compared with the hard drill, U drill out of the hole precision is still a little higher, and finish to be good, especially when the cooling lubrication is not smooth, more obvious, and U drill can be corrected hole position accuracy, hard drill then can not be, you can use the U drill as a rifled knife over the center.
Advantages of U-drilling in CNC machining:
1. U-drill can drill holes on surfaces with inclination angle less than 30~ without reducing the cutting parameters.
2. U-drill can realize intermittent cutting, such as machining intersecting holes, intersecting holes, and intersecting holes, after the cutting parameters of U-drill are reduced by 30%.
3. U-drill can realize multi-step hole drilling, and can bore, chamfer, eccentric drilling.
4. U-drill drilling chips are mostly short chips and can be safely discharged with its internal cooling system without cleaning the chips on the tool, which is conducive to the continuity of product machining, shortening the machining time and improving the efficiency.
5. Under the condition of standard L/D ratio, there is no need to retreat chips when using U-drill to drill holes.
6. U-drill is an indexable tool, no need to sharpen the blade when it is worn out, it is more convenient to replace it, and the cost is low.
7. The surface roughness of holes processed by U-drill is small and the tolerance range is small, so it can replace part of the work of boring tool.
8. U-drill does not 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. U-drill technology not only reduces the number of drilling tools, and because the U-drill adopts a carbide insert set in the head, its cutting life is more than ten times that of an ordinary drill, and at the same time, there are four cutting edges on the insert, which can be replaced at any time when the insert is worn out, and the new cutting saves a large number of grinding and tool replacement time, and improves the efficiency of the work by an average of 6 to 7 times.
Tips for using U-drill on CNC machine tools
1. The rigidity of the machine tool and the alignment of the tool and the workpiece when using the U-drill are high, so the U-drill is suitable for use on high-power, high-rigidity, high-rotation speed CNC machine tools.
2. When using U-drill, the center blade should be selected with good toughness, and the peripheral blade should be selected with relatively sharp blade.
3 processing of different materials, should be used in different groove-shaped inserts, in general, small feed, small tolerances, U drill L/D ratio is large, the choice of cutting force smaller groove-shaped inserts, and vice versa, roughing, tolerances, U drill L/D ratio is small, the choice of cutting force is larger groove-shaped inserts.
4. When using U-drill must consider the machine tool spindle power, U-drill clamping stability, cutting fluid pressure and flow, and at the same time control the effect of U-drill chip removal, otherwise it will largely affect the surface roughness and dimensional accuracy of the hole.
5. When clamping the U-drill, make sure that the center of the U-drill coincides with the center of the workpiece and is perpendicular to the surface of the workpiece.
6. When using the U-drill, select the appropriate cutting parameters according to the different materials of the parts.
7. When the U-drill is trying to cut, do not be afraid to reduce the feed amount or speed, which may break the U-drill blade or damage the U-drill.
8. When U-drill is used for machining, when the blade is worn or broken, analyze the reason carefully and replace the blade with one with better toughness or more wear-resistant blade.
9. When using the U-drill to process stepped holes, be sure to start processing from the large holes first, and then process the small holes.
10. When using the U-drill, pay attention to the cutting fluid to have enough pressure in order to flush out the chips.
11. The blades used on the center and the edge of the U-drill are different, and must not be used by mistake, otherwise the U-drill shank will be damaged.
12. When drilling with a U-drill, the workpiece can be rotated, the tool can be rotated, and the tool and workpiece can be rotated at the same time. However, when the tool is moving in a linear feed, the most common method is to rotate the workpiece.
13. When machining on a CNC lathe consider the performance of the lathe and make appropriate adjustments to the cutting parameters, generally lower speeds and lower feeds.
Problems that often occur in U drill in CNC machining:
1. the blade is damaged too quickly, easy to break, the processing cost increases.
2. Harsh whistling sound when machining, cutting state is not normal.
3. machine jitter, affecting the machining accuracy of the machine.
Points to note on the use of U-drill:
1. The installation of U-drill should pay attention to the positive and negative direction, which blade is upward, which blade is downward, which faces inward, which faces outward.
2. The center height of the U-drill must be corrected, according to its diameter size to require control range, generally within 0.1mm, the smaller the diameter of the U-drill, the higher the center height requirements, the center height is not good U-drill the second side of the wear and tear, the hole diameter will be large, the service life of the blade is shortened, the small U-drill is very easy to break.
3. U-drill on the coolant requirements are very high, must ensure that the coolant from the center of the U-drill shot, the coolant pressure should be the greater the better, you can plug up the excess water outlet of the turret to ensure that its pressure.
4. The cutting parameters of U-drill should be in strict accordance with the manufacturer’s instructions, but also take into account the different brands of inserts, the power of the machine tool, the machining can be referred to the size of the load value of the machine tool, to make the appropriate adjustments, generally using a high speed, low feed.
5. U-drill inserts should be checked frequently and replaced in time, and different inserts should not 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 is, the larger the tool overhang is, and the smaller the amount of travel should be.
7. Do not use excessive wear of the blade, should be recorded in the production of blade wear and the number of workpieces can be processed in relation to the timely replacement of new blades.
8. Use adequate and correctly pressurized internal coolant. The main function of the coolant is chip removal and cooling.
9.U-drill can not be used to process softer materials, such as copper, soft aluminum.