Difference between inclined bed and flat bed, advantages and disadvantages analysis

Comparison of machine tool layout

The plane of the two guide rails of the flat bed CNC lathe is parallel to the ground plane. The plane of the two guide rails of the CNC lathe with inclined bed intersects the ground plane, forming an inclined plane with angles of 30 °, 45 °, 60 ° and 75 °. From the side of the machine tool, the bed of the flat bed CNC lathe is square, and the bed of the inclined bed CNC lathe is right angled triangle. It is obvious that under the same guide rail width, the X-direction carriage of the inclined bed is longer than that of the flat bed. The practical significance of the application of the lathe is that more tool positions can be arranged.

Comparison of machining accuracy

The drive screw of the CNC lathe is a high-precision ball screw. The drive clearance between the screw and the nut is very small, but it does not mean that there is no clearance. As long as there is clearance, when the screw moves in one direction and then reverses the drive, it is inevitable that there will be a reverse clearance, which will affect the repeated positioning accuracy of the CNC lathe, thus affecting the processing accuracy. The layout of the inclined bed CNC lathe can directly affect the clearance of the ball screw in the X direction. The gravity directly acts on the axial direction of the screw, so that the reverse clearance during transmission is almost zero. The X direction screw rod of the flat bed CNC lathe is not affected by axial gravity, and the clearance cannot be eliminated directly. This is the inherent precision advantage brought by the design to the CNC lathe with inclined bed.

Automatic production comparison

The increase of the tool number of the machine tool and the configuration of the automatic chip removal machine are actually laying the foundation for automatic production. One person on duty for multiple machine tools has always been the direction of machine tool development. The inclined bed CNC lathe is equipped with a milling power head, an automatic feeding machine tool or a manipulator to automatically load materials, complete all the chip processes at one time, automatically cut materials and automatically discharge chips, and becomes an automatic CNC lathe with high working efficiency. The structure of flat bed CNC lathe is at a disadvantage in automatic production. Although inclined bed CNC lathe is more advanced than flat bed CNC lathe, its market share is far behind. Flat bed CNC lathes are easy to produce and occupy more than 90% of the market share of CNC lathes.

Cutting rigidity comparison

The sectional area of the NC lathe with inclined bed is larger than that of the flat bed with the same specification, that is, the bending resistance and torsion resistance are stronger. The cutter of the inclined bed CNC lathe cuts from the top to the bottom of the workpiece, and the cutting force is basically consistent with the gravity direction of the workpiece. Therefore, the spindle runs relatively smoothly, which is not easy to cause cutting vibration. While the flat bed CNC lathe cuts, the cutting force generated by the cutter and the workpiece is 90 ° with the workpiece gravity, which is easy to cause vibration.

Chip removal capacity comparison

Due to the gravity, it is not easy to produce winding tools for inclined bed CNC lathes, which is conducive to chip removal; At the same time, with the central screw rod and guide rail to protect the sheet metal, the chip can be prevented from accumulating on the screw rod and guide rail. Inclined bed CNC lathes are generally equipped with automatic chip removal machines, which can automatically remove chips and increase the effective working time of workers. It is difficult to add an automatic chip removal machine to the flat bed structure