Tool selection -2

In addition to the material of the cutter, the tool selection, the tool shank, the structure, the method and the cost are also included.

1.tool shank

The knife handle with the increase of the cutting speed, the spindle / toolholder interface performance under the influence of centrifugal force changes directly affect the machining accuracy of the workpiece and the surface roughness, therefore, to adapt to the connector tool to the NC machine tool and machining clamp and machine tools, such as HSK heat sleeve handle, handle, handle hydraulic and other new tool has been widely used.

2.tool structure

In order to improve production efficiency and reduce tool change time, the auto parts processing, the increasing use of a variety of composite tools, such as drilling and boring and reaming composite, composite, composite drill and thread processing etc. The complex structure of the expansion tool to meet a lot of special processing requirements, and even some tool the development of a machine, electrical, hydraulic integration device, has been far beyond the traditional concept of the tool; because the powertrain uses a lot of processing in the production procedure, production directly affects the working procedure of the production, in order to improve production efficiency and reduce production cost, and uses the combined tool a large number of and the resulting non-standard cutting tools.

3.tool cost

The tool consumption is related to many factors, requires specific conditions. In general the tool cost at the same time, more important is to see the cost of a single product processing tool consumption. Not only to see the tool cost directly, but also depends on the tool influence on production efficiency and changes of the total manufacturing cost caused by the the performance of the new knife. The life and influence on the purchase price of the tooling cost is very large, while the number of heavy grinding tools, heavy grinding times and grinding costs, the total cost of the tool also has a significant impact; therefore, the need to consider the time of equipment and tool of investment and long-term consumption of tool the relationship between costs, need to consider and balance.

Tool selection -1

In order to ensure the efficiency of equipment and production line processing cycle balancing, we need to consider the appropriate tool and production line equipment in the match. Therefore, tool selection is reasonable or not will directly affect the quality and efficiency of processing, therefore, should choose the tool of the following aspects:

1.processing equipment

The first is to understand the performance of processing equipment, only to understand the performance of the equipment, or to choose the appropriate tools to match, whether individually selected equipment or tool, its efficiency can play out. In recent years relevant data show that the value of a few million end mills, may affect a value of millions yuan of equipment efficiency. In the process of planning, design and arrangement of the tool determines the cost of manufacturing stage and tool cost to a great extent.

2.tool material

The high-speed development of manufacturing technology, the cutting tool of the increasingly high demand. In order to meet the needs of high-speed cutting tools, new materials have been widely used. The use of new materials to greatly improve the efficiency of cutting tool, high cobalt, high vanadium, high performance, high speed steel tool durability can be increased by 1.5-3 times than the ordinary high speed steel, the powder metallurgy high speed steel strength can improve toughness of 20%-30%, increased 1.5-2 times, and reliability than ordinary high speed steel increased significantly, while the CBN (cubic boron nitride), PCD (polycrystalline diamond tool) and ceramic tools represent the development level of the technology of superhard cutting tool, cutting speed can be increased several times than the hard alloy. Greatly improve the processing efficiency.

The effect of the helix angle of the milling cutter

When the helix angle is larger, the roughness of the face will be more ideal. When the helix angle is larger, the fluctuation surface will be worse. In the reverse milling, the change of the helix angle has no effect on the precision of the machining plane, but there is a considerable effect when the milling is done. When the helical angle when the milling is smaller, the precision of the processing surface will be worse, especially when the spiral angle of 10 degrees is quite obvious. Because the cutting force of the milling is smaller than that of the reverse milling, when the helix angle is small, the cutting will have more intense impact. The larger the helix angle, the worse the chip removal. Low helix angle is more suitable for milling ditch, high helix angle is not suitable for milling ditch. High helix angle milling ditch Cao will use a small amount of fast cutting method, which is the latest method. Comparison of Cutting Resistance in Different Helix Angle. The smaller the helix angle, the greater the cutting torque, the smaller the helix angle is, the smaller the cutting torque is. The smaller the helix angle, the smaller the axial tension, the greater the greater the axial angle of the opposite helix angle. If you use a larger helix angle of the end mill, you must use a strong grasp of the force of the chuck. The angle of the high helix angle end mill is sharper and less likely to crack than the low helix angle. If the angle is large, the diameter of the gun will be smaller, so the tool life can be extended.

Components of carbide endmills

As with all artificial products, manufacturing cutting blades must first solve the problem of raw materials, which determine the composition and formula of blade material. Most of the blade are made of hard alloy, the main components of tungsten carbide (WC) and cobalt (Co).WC is the blade in hard particles, Co as binder the blade can be formed.

Change the method of hard alloy properties simply by varying the grain size of WC particles. With larger particle size (3 – 5 m) WC particles were prepared by the hard alloy material has low hardness, easy to wear; with smaller particle size (< 1 m) WC particles can produce hardness high, good wear resistance, but also more brittle hard alloy material. The metal material in the processing of hardness is very high when using fine grain cemented carbide inserts may obtain the ideal processing effect. On the other hand, the coarse grain cemented carbide in intermittent cutting or other performance requirements of high toughness blade machining is more superior.

Another way to control the characteristics of cemented carbide blades is to change the ratio of WC to Co. The hardness of Co is much lower than that of WC, but the toughness is better. Therefore, reducing the Co content will result in a higher hardness blade.

How to improve the service life of cutting tools?

How to improve the service life of the cutter? In order to surviving and developing, our factory must spare no effort to reduce production costs, including: improving ways of improving employee productivity, prolong tool life, improve material management, reduce energy consumption and so on. Our technical staff of precision manufacturing a can prolong tool life, improve the quality of parts, effective method to reduce the manufacturing cost of the tool. After passivation, deburring, polishing the instrument in the three dimension of the tap cutting edge by magnifying inspection, found that tap the surface is smooth, no small particles before polishing, so that the tool is not easy to collapse teeth, bright surface, thus improving the service life. The success in the first trial. The method is applied to all cutting tools. Through processing in each cycle begins after brushing or cutting edge, the cutting tool life increased by 2-4 times of convertible range. A ceramic insert has also been tested for more than 6 months. Brush cutting advantages include improving the quality of the parts, prolong tool life, reduce the tool for reducing inventory, and increase the processing time of frequency changer machine. In order to further prolong tool life, our technical staff also tried to use abrasive particles (such as aluminum oxide or silicon carbide abrasive) brush to brush the cutting edge, but this method is not successful in all cases, the tool life was reduced. The tool machine tool passivation, passivation, tool grinding, cutting equipment, tungsten steel knife, tool polishing equipment used in machine tool industry in the milling cutter, drill, all can improve the cutting tool, is three times the average service life of the cutter.

Attention in the use of tungsten carbide milling cutter

In the milling cutter, the rotation direction of the feed direction of the workpiece tungsten steel milling cutter and the cutting area. The same chip thickness from the start will be gradually reduced, until the incision in the peripheral milling end of the zero check; in inverse milling (also known as reverse milling), the rotation direction of the milling cutter feeding direction of the workpiece and the cutting area is just the opposite. The chip thickness to zero, and then with the cutting process gradually increased.

In inverse milling cutter, tungsten carbide cutter blade from zero chip thickness at the start cutting, it will have a very high cutting force, so as to promote the tungsten steel milling cutter and the workpiece away from each other. The blade is forced into the incision cutter, usually by cutting blade and is caused by the contact machining hardened surface at the same time, friction and polishing effect in friction and high temperature effect. The cutting force is more likely to work off the bench.

In milling cutter, tungsten steel milling cutter blade starts cutting from the maximum chip thickness. It can reduce the heat and decrease machining hardened to avoid polishing effect. The trend of lotus very favorable application of maximum chip thickness and cutting force, the easier it will be to push workpiece tungsten steel milling cutter, the tungsten carbide cutter blade cutting no matter how. Machine tool, fixture and workpiece requirements, milling is the preferred method.

In the milling cutter, cutting sometimes adhered or welded to the cutting edge, and gathered around the starting next cutting. Inverse milling, cutting can be easily intercepted or wedged between the blade and the workpiece, which will lead to blade rupture. And when the milling, the same chip breaking will not damage the cutting edge One divides into two.