CNC machine tools of characteristics of mechanical structure

High static and dynamic stiffness

Machine tool stiffness refers to the ability to resist deformation under the action of cutting force and other forces. CNC machine tool must work under high speed and heavy load conditions. The deformation of supporting parts such as machine bed, base, column, worktable and tool rest will directly or indirectly cause the relative displacement between the cutter and the workpiece, thus causing the machining error of the workpiece. Therefore, these supports should have high static and dynamic stiffness.

High vibration resistance

When the machine tool is working, it can produce two kinds of vibration, namely forced vibration and self-excited vibration (or chatter). The vibration resistance of machine tool refers to the ability to resist these two kinds of vibration. In order to ensure the high precision and high surface quality of the workpiece, the numerical control machine tool should be free of vibration under the condition of high-speed heavy cutting, especially to avoid chatter during cutting.

High sensitivity

CNC machine tool controls the relative motion between tool and workpiece by digital information, which requires high precision in a large range of feed rate, so the moving parts should have high sensitivity. Rolling guide rail, plastic guide rail and static pressure guide rail are usually used to reduce friction force and make it free from creeping phenomenon at low speed. The movement of worktable, tool rest and other parts is driven by AC or DC servo motor and driven by ball screw, which reduces the driving torque required by the feed system and improves the positioning accuracy and motion stability.

Small thermal deformation

The heat source that causes the machine tool to become hot is mainly the internal heat source of the machine tool, such as motor heat, friction heat and cutting heat. Thermal deformation is the reason that affects the machining accuracy. Due to the uneven distribution of heat source and the uneven quality of parts, the temperature rise of each part is different, resulting in uneven thermal expansion deformation, which affects the correct relative position of the tool and the workpiece.

High degree of automation, easy to operate

CNC machine tool is a kind of processing equipment with high degree of automation. In terms of the operability of the machine tool, we pay full attention to the interlocking ability of each part of the machine tool to prevent accidents. At the same time, the observation, operation and maintenance conditions of the operator are improved to the maximum extent. The emergency stop device is provided to avoid accidents.