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                Cutting tool grinding technology base

                Font Size: [Big][Mid][Small] 2013-7-31  Views: 632

                Cutting tool grinding technology base
                A, cutting tool material
                Common in tool grinding of cutting tool materials are: high speed steel (HSS) and powder metallurgy HSS (PM HSS), cemented carbide (HM) and PCD, CBN, metal, ceramic and other superhard materials. High speed steel cutter, good toughness and sharp cemented carbide cutting tools, high hardness but poor toughness. The density of carbide cutting tools
                Significantly greater than high speed steel tools. These two materials is the main material of drill, reamer, cutter and tap. Powder metallurgy HSS performance between these two materials, mainly used in the manufacture of coarse milling cutter and tap.
                Material for high speed steel cutting tools for good toughness and so less sensitive to collision. High hardness and brittle, but the carbide cutting tools is sensitive to the collision, the blade is easy to jump. So, in the process of grinding, must be placed to the operation of the carbide cutting tools and very careful, prevent collisions or fall of tools.
                Due to the precision of HSS cutting tools are relatively low, the grinding requirements is not high also, plus the price is not high also, so, many manufacturers set up on the grinding tool workshop. But often need to professional carbide cutting tools for grinding grinding center. According to Arnold tool grinding center, repairing tools is more than 80% in carbide cutting tools.
                Second, the tool grinding machine
                Due to the cutting tool material is very hard, so, normally only grinding is used to change its shape. Common in the tool manufacturing, grinding tool grinding machine has the following kinds:
                1: grinding machine grinding bit, endmill cutter groove or back.
                2 vertex Angle machine: grinding bit cone apex Angle (or eccentric Angle).
                3 take horizontal milling machine: fixed chisel edge of drill bit.
                4 manual universal tool grinder: cylindrical grinding, trough, back, apex Angle and horizontal, flat, before the knife blade surface, etc. They can be used for less quantity, complex shape tool.
                5 CNC grinding machine: usually five-axis linkage, function determined by the software. Commonly used in the large size of grinding, precision demand is high, but not sophisticated tools, such as the drill bit, end milling cutter, reamer, etc. Major supplier of this kind of grinding machine from Germany, Switzerland, the United States, Australia and Japan.
                Three, grinding wheel
                1 grits
                By means of different material, grinding wheel is suitable for grinding of cutting tools made of different materials. Tool grinding particle size of the different parts of the need to use is different also, to ensure the best combination of edge protection and machining efficiency.
                Alumina: for grinding HSS cutting tools. Grinding wheel and cheap, easily modified into different shape is used for grinding complex
                (corundum) miscellaneous cutting tool.
                Silicon carbide: for correction CBN grinding wheel and diamond wheel.
                CBN (cubic boron carbide) : for grinding HSS cutting tools. The price is high, but durable. Internationally, grinding wheel
                B, such as B107, of which 107 indicates the size of the particle diameter.
                Diamond: for grinding HM knives, price is high, but durable. Use D to represent the grinding wheel, e.g. D64, its
                In 64 indicates the size of the particle diameter.
                2 the shape
                For the convenience of different parts of the grinding tools, grinding wheel should have different shape. The most commonly used are:
                Parallel grinding wheel (1 a1) : grinding vertex Angle, diameter and back.
                - disc wheel (12 v9, 11 v9) : grinding spiral groove, milling cutter, cutting edge, repair the chisel edge, etc.
                Grinding wheel over a period of time after the use of the need to modify its appearance (including plane, angles and rounded R). Grinding wheel must often use clear stone grinding filled in the intergranular chip cleared in order to improve the grinding ability of grinding wheel.
                Fourth, grinding standard
                Whether to have a good tool grinding standard is to measure whether a grinding center professional standards. Grinding in the standard, general provisions in different cutting tool in cutting different materials when the cutting edge of technology parameters, including the blade Angle, apex Angle, rake Angle, Angle, blade, after chamfering etc parameters (in the carbide drill, make the blade passivation process is called "blade", pour the width of the blade and the cutting material, generally between 0.03 0.25 mm. (tip) on the edge of the edge chamfering process is called "chamfering".) . Each company has its own summary professional grinding standard.
                HM, the difference between the bit and HSS drill bits:
                HSS drill: apex Angle is 118 degrees commonly, sometimes more than 130 degrees; Sharp blade. For high precision (blade
                Poor, symmetry, circumferential beating) demand is relatively low. Chisel edge has a variety of practices.
                HM bit: apex Angle is 140 degrees commonly; Straight flute drill often is 130 degrees, three blade drill is 150 degrees. The edge of the blade and blade (edge) are not sharp, tend to be passive, or inverted blade and chamfer; The high accuracy requirement. S - shaped chisel edge is often, to facilitate chip breaker.
                After the Angle:
                After the blade Angle for the cutting tool is very important. Angle is too big, after the blade virtual easily jump, "Mr. Dao"; After the Angle is too small, the friction is too big, cutting.
                Tool Angle after over by cutting material and cutting tool type, tool diameter varies. In general, after Angle decreases with the cutter diameter larger. In addition, be hard cutting material, after Angle smaller, otherwise, the Angle is big.
                Five, the tool detection equipment
                Tool testing equipment general points in three categories: the knife instrument measuring instrument, projectors and universal tools. To knife instrument is mainly used for machining center, numerical control equipment of knife preparation (e.g., length, etc.), is used to detect parameters such as Angle, radius, long ladder; The function of the projector is used to detect parameters such as Angle, radius, long ladder. But the two generally cannot Angle after measuring tool. While universal tool measuring instrument can measure most of the geometric parameters of cutter, including Angle.
                So, professional tool grinding center must be equipped with universal tool measuring instrument. But this kind of equipment suppliers, there are German and French products on the market.
                Six, grinding mechanic
                The best equipment and the need for personnel operations, grinding the mechanic training nature is one of the most key link. After tool manufacturing industry is relatively backward in our country, and a grave shortage of vocational and technical training, cutter grinding technician training can only be solved by enterprises themselves.