A brief analysis of the characteristics and performance of inclined bed CNC lathes

1 Features

(1) The inclined guide CNC lathe is driven by a servo spindle and has large output torque at low speed.

(2) The spindle of the inclined guide CNC lathe adopts a spindle unit, which has low noise, high speed and long service life.

(3) Mechatronics design, beautiful appearance and reasonable structure.

(4) The vertical and horizontal guide rails adopt high-precision linear guide rail pairs, which have high positioning accuracy, good dynamic performance, and fast moving speed, up to 20m/min.

Generally speaking, flatbed CNC lathes are economical CNC lathes or simple CNC lathes in China. Currently popular CNC lathes and full-function CNC lathes have slanted beds.

The CNC flat bed lathe is a simple CNC transformation of an ordinary lathe, with incomplete consideration of automation. The inclined bed CNC lathe is developed and designed based on CNC machining principles and is highly targeted. Compared with plane CNC lathes, the layout, rigidity, precision and chip removal capabilities of lathes have been significantly improved. These advantages are innate and cannot be diminished by manufacturing means.

2 lathe layout

flatCNC latheThe planes of the two guide rails are parallel to the ground plane. The planes of the two guide rails of a CNC lathe with a tilted bed intersect with the ground plane, forming an inclined plane with angles of 30, 45, 60, and 75. Viewed from the side of the lathe, the bed of a flat bed CNC lathe is square, while the bed of a slant bed CNC lathe is a right triangle. Obviously, under the same guide rail width, the x-direction trolley with an inclined bed is longer than the x-direction trolley with a flat bed. The practical significance of applying it to lathes is that more tool positions can be arranged.

3. Cutting stiffness

The cross-sectional area of ​​a CNC lathe with an inclined bed is larger than that of a flat bed of the same specification, which means it has stronger resistance to bending and torsion. The tool of a CNC lathe using a tilt lathe cuts obliquely above the workpiece, and the cutting force is basically consistent with the direction of gravity of the workpiece. Therefore, the spindle runs relatively smoothly and is less likely to cause cutting vibration. When CNC lathes and flat lathes are cutting, the cutting force generated by the tool and the workpiece is at 90 degrees to the gravity of the workpiece, which can easily cause vibration.

4. Lathe processing accuracy

The transmission screw of the CNC lathe is a high-precision ball screw. The transmission gap between the screw and the nut is very small, but it does not mean that there is no gap. As long as there is a gap, when the screw moves in one direction and then is driven in the opposite direction, a backlash will inevitably occur, which will affect the repeated positioning accuracy of the CNC lathe and thus the machining accuracy. The layout of the inclined bed CNC lathe can directly affect the clearance of the ball screw in the X direction. Gravity directly acts on the axial direction of the screw, making the backlash during the transmission process almost zero. The x-direction screw of the plane CNC lathe is not affected by axial gravity and cannot directly eliminate the gap. This is an inherent precision advantage that this design brings to bevel lathes.

5. Chip removal ability

CNC lathes with slanted beds are difficult to wrap around the tool due to gravity, which is conducive to chip removal; at the same time, the sheet metal is protected by combining the intermediate screw and guide rail to prevent chips from accumulating on the screw and guide rail. Inclined bed CNC lathes are generally equipped with an automatic chip removal machine, which can automatically remove chips and increase the effective working time of workers. It is difficult to add an automatic chip remover to the flat bed structure.

6 Automatic production comparison

The addition of lathe tool positions and the configuration of automatic chip removers actually lay the foundation for automated production. One person working multiple lathes has always been the development direction of lathes. The inclined bed CNC lathe is equipped with a milling power head, an automatic feed lathe or a manipulator, which can automatically feed materials, complete all chip cutting processes at one time, automatically discharge materials, and automatically remove chips, thus becoming a fully automatic CNC lathe with high work efficiency. The flat bed structure of CNC lathes has shortcomings in automated production. Although inclined bed CNC lathes are more advanced than flat bed CNC lathes, their market share lags far behind. Flatbed CNC lathes account for more than 90% of the market share of CNC lathes due to their low price and convenient production.

Relatively speaking, the disadvantages of the inclined bed CNC lathe are that it is difficult to manufacture, the bed is heavy, and it requires a servo motor with a braking function in the X direction. The key is that the cost is high, so the price is relatively higher than that of a flat bed.