U drill bit, also known as indexable insert end mill, is an efficient and universal hole processing tool. It consists of a center blade and a peripheral blade. The blade does not need to be sharpened after wear and can be directly replaced. It has good economy and maintainability. U drill bit can be widely used in hole processing of CNC machine tools, machining centers, boring machines and other equipment. It is suitable for processing various materials, including steel, cast iron, aluminum alloy, stainless steel, etc.
Advantages of U Drill Bit
First of all, the difference between U drill bit and ordinary drill is that U drill bit uses blade peripheral blade and center blade. From this perspective, the relationship between U drill bit 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 the part.
U drill bit has better rigidity and can adopt a very high feed rate. Moreover, the processing diameter of U drill bit is much larger than that of ordinary drill, and the maximum can reach D50~60mm. Of course, U drill bit cannot be made too small due to the characteristics of blade installation.
U drill bit only needs to replace the blades of the same type and different brands when encountering various materials, while hard drill is not so convenient.
Compared with hard drill, the hole precision drilled by U drill bit is still higher, and the finish is better, especially when the cooling and lubrication are not smooth, which is more obvious. Moreover, U drill bit can correct the position accuracy of the hole, which is not the case with hard drill. U drill bit can be regarded as a bore cutter.
Advantages of U-drill Bit in CNC Machining
U drill bit can drill holes on surfaces with an inclination angle of less than 30° without reducing cutting parameters.
After the cutting parameters of U drill bit are reduced by 30%, intermittent cutting can be achieved, such as processing intersecting holes, intersecting holes, and interpenetrating holes.
U drill bit can drill multi-step holes, and can bore holes, chamfer holes, and eccentric holes.
When drilling with U drill bit, 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.
Under standard aspect ratio conditions, there is no need to remove chips when drilling with U drill.
U drill bit is an indexable tool. The blade does not need to be sharpened after wear. It is convenient to replace and the cost is low.
The surface roughness value of the hole processed by U drill bit is small, the tolerance range is small, and it can replace part of the boring tool.
When using U drill bit, 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.
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 inlaid on the head, its cutting life is more than ten times that of an ordinary drill. 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 edge saves a lot of time for grinding and replacing tools, and can improve work efficiency by an average of 6-7 times.
Tips for Using U Drill Bit on CNC Machine Tools
U drills bit have high requirements on the rigidity of machine tools and the centering of tools and workpieces when used. Therefore, U drills bit are suitable for use on high-power, high-rigidity, and high-speed CNC machine tools.
When using U drills bit, the center blade should be a blade with good toughness, and the peripheral blades should be sharper.
When processing different materials, blades with different grooves should be selected. Generally, when the feed is small, the tolerance is small, and the U drill bit aspect ratio is large, a groove blade with smaller cutting force should be selected. On the contrary, when rough processing, tolerance is large, and the U drill bit aspect ratio is small, a groove blade with larger cutting force should be selected.
When using U drills, it is necessary to consider the machine tool spindle power, U drill bit clamping stability, and the pressure and flow of the cutting fluid. At the same time, the chip removal effect of the U drill bit should be controlled well, otherwise the surface roughness and dimensional accuracy of the hole will be greatly affected.
When clamping the U drill bit, it is necessary to make the center of the U drill bit coincide with the center of the workpiece and be perpendicular to the workpiece surface.
When using U drills, it is necessary to select appropriate cutting parameters according to different part materials.
When using a U drill bit for trial cutting, be sure not to reduce the feed rate or speed arbitrarily out of fear, which may cause the U drill bit blade to break or damage the U drill bit.
When using a U drill bit for processing, if the blade is worn or broken, carefully analyze the cause and replace it with a blade with better toughness or more wear resistance.
When using a U drill bit to process step holes, be sure to start with the large hole first and then the small hole.
When using a U drill, pay attention to the fact that the cutting fluid must have sufficient pressure to flush out the chips.
The blades used for the center and edge of the U drill bits are different. Do not use them incorrectly, otherwise the U drill bit shank will be damaged.
When using a U drill bit for drilling, 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 moves in a linear feed mode, the most common method is to use the workpiece rotation mode.
When processing on a CNC lathe, the performance of the lathe should be considered and the cutting parameters should be adjusted appropriately, generally by reducing the speed and feed.
Common Problems of U Drill Bit in CNC Machining
The blade is damaged too quickly and easily broken, which increases the processing cost.
During processing, a harsh whistling sound is emitted, and the cutting state is abnormal.
The machine tool vibrates, affecting the processing accuracy of the machine tool.
Points to Note When Using U Drill Bit
When installing a U drill bit, 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.
The center height of the U drill bit must be corrected, and the control range is required according to its diameter. Generally, it is controlled within 0.1mm. The smaller the diameter of the U drill bit, the higher the center height requirement. If the center height is not good, the two sides of the U drill bit will wear, the aperture will be too large, and the service life of the blade will be shortened. Small U drills are easy to break.
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.
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 should 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.
The blades of the U drill should be checked frequently and replaced in time. Different blades cannot be installed in reverse.
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.
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.
Use sufficient internal coolant with the correct pressure. The main function of coolant is chip removal and cooling
U drills cannot be used to process softer materials, such as copper, soft aluminum, etc.
