Improvement of the Geometry Angle of Milling Cutter

Improvement of the Geometry Angle of Milling Cutter

    According to the experience of nuclear power, when the power of the machine tool is insufficient, the geometric angle of the tool can be correctly selected, and the production capacity of the low-power machine tool can also be expanded. For example, cast iron milling cutters traditionally have negative axial and radial rake angles (double negative milling cutters). This negative geometry angle makes the cutting edge VBMT Insert relatively strong. Conversely, positive and negative angle milling cutters (positive axial rake angle, negative radial rake angle) cut smoothly, which also reduces machine power requirements and makes it easier to use advanced tool materials.

   Depending on the grade and application of the insert, the cutting edge of the tool insert can be sharp or ground with a chamfer from 0.013 to 0.076 mm. For Kyon 3500 ceramic inserts, a 20° chamfer was ground with a chamfer width of 0.2mm to prevent the cutting edge from being damaged by chips at high speeds.

    Kennametal's Fix-Perfect system is a product line that combines different positive and negative angles. Its characteristic is that the positive radial rake angle and negative axial rake angle of the blade have the opposite shearing effect (positive axial rake angle, negative radial rake angle) with Carbide Turning Inserts the positive and negative angle milling cutters. Since the blade is vertical, the lower part of the blade has strong physical support, which increases the strength of the blade. The negative axial rake angle forces the cutting force towards the spindle and the milling cutter works stably. Also, the negative axial rake angle allows the "impact point" that first cuts into the workpiece to leave the tool tip, protecting the tool tip.

    Fix-perfect tools have scrapers for roughing and finishing. Surface roughness up to 32 (contour rms deviation) reduces one finish and reduces cycle time.

    The tool should adapt to changes in various parts of the car.

    Due to its toughness and high compressive strength, as well as its ability to be cast into very complex shapes, cast iron has been used to make car engine casings and other parts. Later, under the promotion of CAFE (Corporate-average-fuel-efficiency), the use of heavy alloys was reduced on light vehicles. According to the American Foundry Association, the weight of cast iron for family cars in 1980 was limited to 600 pounds. By 1999, the average had dropped by nearly half, to 325 pounds, and is expected to drop to 230 pounds in 2006. On the other hand, Aluminum Analysis predicts that the application of aluminum automotive parts will grow by 50% in 5 years, from 250 pounds per vehicle in 2000 to 380 pounds per vehicle in 2005.

    The machining of high-volume aluminum parts requires the use of polycrystalline diamond (PCD) tools. Chips generated during machining are the main cause of PCD tool damage.

    To maintain the integrity of the cutting edge of a PCD tool, it is best to distribute the cutting load evenly across each cutter. Therefore, fine adjustment (especially axial) is an important means to prolong the life of PCD milling cutters. For example, Ingersoll knives' Flex-Lok inserts allow fine-tuning of vertical inserts, which are then secured with barrel screws. In this way, the load on each insert on the milling cutter is balanced, maximizing tool life.

    The machining of aluminum alloys has special requirements on the geometric angle of the tool. Aluminum alloys used in the aerospace industry should use large positive milling cutters due to their high viscosity and low silicon content. For cast aluminum alloys with high silicon content in the automotive industry, the rake angle does not have to be sharp, but it must be stable and durable. Therefore, most car manufacturers use aluminum alloys with small positive axial and radial rake angles.

    Additionally, some auto parts are now hardened to increase productivity and reduce costs. For work-hardened ferrous metals, milling cutters with CBN or ceramic inserts are available.

The threading insert Blog: https://jacobupton.exblog.jp/