Although the CNC machine tools also have the bed and column, guide rail, operating table, tool holder and other components of ordinary machine tools. But in order to and control system of high precision, high speed control compared to the host part of the machine tool structure design also put forward high precision, high stiffness, low inertia, low friction, no gap, high resonance frequency, appropriate damping ratio and other requirements. Due to the specific performance of the mechanical structure form, the core factor to achieve performance is the achievability of the key components of CNC machine tools have significant changes in the structural design.
Structural characteristics of CNC machine tool equipment.
A, the structural characteristics of the basic components
(1) the main role of the foundation parts CNC machine tool foundation parts are an important foundation, their basic function is to support the support and maintain the relative position of the executive organs. CNC machine tools in one, not only to be able to withstand the rough work when the big eat, big tool cutting force, but also to ensure that the precision of precision work.
(2) the performance requirements of the basic components of the structural design of the foundation in strength, stiffness, vibration resistance, thermal deformation and internal stresses have put forward high requirements.
(3) Improvement methods of foundation parts The casting adopts fully closed section, reasonable arrangement of partition and ribs, sand-containing modeling or filling with concrete and other materials, widening of guide surface, lathe adopts inclined bed and guide, which also facilitates chip removal, bed and column tools are welded with steel, which can obviously improve its stiffness, and according to the layout of thermal symmetry principle, it can also increase heat dissipation and heat insulation effect.
Second, the structural characteristics of the transmission module
(1) the main role of the transmission module main drive module to achieve a variety of cutting power required by the tool and tool, and in a large range of speed to ensure constant power output, while the cutting speed for CNC machine tools can be obtained, the main drive must be in a wide range of stepless variable speed. Current CNC machine tools using high-performance DC and AC stepless speed spindle motor, the machine tool’s graded variable speed drive chain is greatly simplified.
(2) the performance requirements of the drive module has a direct impact on the accuracy of the spindle assembly accuracy, stiffness, vibration resistance and thermal deformation performance requirements. This can be ensured by the structural design of the spindle assembly and the reasonable combination of bearings and the selection of high-precision special bearings.
(3) Drive module improvement methods In improving the efficiency and automation, the spindle application tool or tool automatic clamping, chip and cutting, quasi-stop. The new ceramic spindle, light weight, low thermal expansion, with high precision and accuracy.
Third, the characteristics of the feed module
(1) The main role of the feed module The module driven by the motor, ball screw and tool or workpiece to complete the movement in all directions.
(2)The performance requirements of the feed module When designing the mechanical device, the design of the mechanical set up, to no clearance, low height, height degree as the principle.
(3) the improvement method of the entry module With low friction, light drag, efficient ball screw and linear rolling guide; motor directly connected to the screw, simplifying the entry drive chain; elimination of gap device to eliminate the gear, screw, coupling transmission gap; 4 to the rolling guide and screw pre-load tension.
IV. Structural characteristics of other models
(1) operating table CNC milling and CNC milling center, using the internal structure has the characteristics of the CNC entry drive mechanism of the rotary, circumferential indexing and feed movement at any angle. For multi-process CNC machine tools, the configuration of automatic exchange of operating tables to further shorten the auxiliary time.
(2) tool holder module rotary tool holder. Replace the spindle tool change and automatic tool change module with tool magazine and multiple tool holders, multiple spindle layout plays an important role in improving efficiency and automation level. In order to make the tool in the machine tool positioning, clamping up, in some places, there are some standard tool means and machine clamps.
(3) CNC accessories The role of machine tool accessories is to work with the machine tool to achieve automation. CNC machine tool-specific accessories are: 1 to the tool instrument, 2 automatic chip conveyor, 3 automatic chip conveyor, material storage and loading and unloading devices, 5 automatic cooling and lubrication and a variety of new supporting parts such as guide guards.
(4) lubrication module Cutting oil filling method that the needle for different objects taken in different ways for lubrication, in the way of oil injection, a variety of processes with other work phase. Cutting oil system lubrication is sufficient, the amount of oil supply is easy to control, heat dissipation and the ability to remove impurities, through the oil pump will be cutting oil from the oil tank suction after delivery to the need to cut parts. Oil injection methods are: drip oil way, splash way, spray oil way, etc.
Post time: Mar-02-2023