Product Made In Japan
Manufacture: Yamashina Seiki
Model: NC

Overview

NC facing is a processing method in which, in addition to the Z-axis in the direction of the spindle’s center axis, another moving axis (U-axis) is provided in the radial direction of the spindle and driven by an NC. Our previous NC facing units were medium-speed (1500 rpm or less), high rigidity, capable of heavy cutting, and highly accurate for machining steel. The newly developed unit is a high-speed, high-precision, light-cutting unit.

The Main Points

1. High-speed spindle rotation — 5000 rpm (compatible with all strokes)
2. Maximum U-axis stroke — 26mm (radius value)
3. Comes with an ATC mechanism.
F = αWrn2 (F: centrifugal force, α: constant, W: weight, r: center of gravity radius offset, n: rotation speed) If the current planned rotation speed is 5000 rpm, the weight of the moving object W = 1 kg, the maximum center of gravity offset amount r = 13mm, the generated centrifugal force will be 3500N. If left as is, this force not only becomes a source of vibration and causes large vibrations to the machine, but also the centrifugal force returns to the drive system, which in some cases may even damage the drive system, making it unsustainable as a machine. To solve this problem, this mechanism uses an eccentric shaft configuration that does not cause the center of gravity to shift within the rotating head. Due to the eccentric shaft configuration, there is no centrifugal force acting on the outside of the head, including the drive system, so it is safe. What’s more, we were able to make it extremely compact and lightweight.
Another major feature is that if the above-mentioned eccentric shaft is used alone, the rake angle of the cutter will change significantly when the shaft is rotated and the cutter is moved in the radial direction. However, in this machine, the eccentric shaft has a double structure, and by mechanically reversing and synchronizing it, the travel distance is quadrupled and the rake angle of the cutter remains constant. Since centrifugal force does not act externally, there is no reversal of play direction due to centrifugal force, and smooth facing processing is possible over the entire stroke.
This unit is capable of machining multiple diameters with just one tool, and has a wide range of uses. However, in order to meet the market’s needs for using a variety of tools, it is configured to allow ATC. All the worries and dissatisfaction that were experienced during conventional machining (for MC + U-axis machining) are resolved in one fell swoop. At our company, we are actively developing the system with a view to meeting various needs for even higher speeds.