Vertical machining centers are mainly suitable for processing board, disc, mold and small shell complex parts. Vertical machining centers can finish milling, boring, drilling, tapping and cutting threads. Its price is expensive and its processing cost is much higher than that of traditional machine tools, which requires that measures must be taken to greatly compress the single piece processing time. The good design is beneficial to the processing efficiency and quality of the vertical machining center.
1, with a higher static motion. The vertical machining center is expensive, and its processing cost is much more than the traditional machine tool. This requires that measures must be taken to greatly compress the single piece processing time. The processing time of compression piece includes two aspects one is the development of new tool materials, cutting speed were greatly increased greatly by reinstated cutting time; on the other hand, the automatic tool changing system, accelerate the transformation of the clamping operation, and greatly reduce the auxiliary time. These measures have greatly improved the productivity and achieved good economic benefits. However, the load and operation time of the machine tools are obviously increased. When designing the machining center structure, considering the above, the main parts are usually closed box structure, reasonable layout of stiffeners and strengthening of the contact wind of all components, which effectively improves the static and dynamic characteristics of machine tools. In addition, adjusting the quality of components may change the natural frequency of the system, increasing damping can improve the damping characteristics of machine tools, and it is an effective measure to improve the dynamic and dynamic characteristics of machine tools.
2. It has static stiffness. The structural stiffness of the machine tool bed, the guide rail, the worktable, the tool holder and the spindle box will affect the geometric accuracy of his own and the error caused by the deformation. All these factors require the numerical control machine to have higher static stiffness. The vibration of cutting process not only directly affects the machining accuracy and surface quality, but also reduces the tool life and affects the productivity. And the machining center is continuous operation. It is impossible to eliminate or reduce vibration in the process of machining, such as changing the cutting amount or changing the geometric angle of the tool, so we must also improve the dynamic stiffness of the machining center.
3. It has smaller thermal deformation. Machining center is affected by internal and external heat sources, such as cutting heat, friction and heat, and all parts will undergo different degrees of thermal deformation, which will affect the machining accuracy of the workpiece. The spindle speed, feed speed and machining center cutting quantity are larger than that of the conventional machine tools, and process automation, is often a continuous process, thus the heat generated is more effective cooling, cold temperature control purchase method; improve the structure of machine tools, the component deformation occurred in the non sensitive direction error. For example, the column of horizontal machining center adopts a frame type double column structure, the left and right symmetry, the thermal deformation of the spindle axis to move the lifting direction, it can be compensated by coordinate correction, reduce heating, and isolate the heat source from the main engine as far as possible.
4, the friction between moving parts and small gap eliminating transmission system. The displacement of the worktable of the machining center is the minimum unit of the pulse equivalent. In the case of the knife, the worktable often moves at a very low speed. This requires working table of NC device instructions can be issued to make an accurate response, it is related with the friction of moving parts, machining center with rolling guideway, static friction small rolling guide and hydrostatic guideway, and the lubricating oil under the action of the friction force decreases with the movement speed increase, which effectively to avoid the crawling phenomenon, so that the motion balance and positioning accuracy of machining center are improved. In the feed system, the ball screw is used instead of the sliding screw, which is based on the same reason. In addition, the pitch compensation pulse compensation device, eliminating the gap feed transmission system, some machine adopts gapless gear.
5, high life and good accuracy. A good lubrication system ensures the life of vertical machining centers, and guides, feed screws and spindle components adopt new wear-resistant materials, so that machining centers can maintain good accuracy in long-term use.
6. Humanized design. The machining center adopts a spindle, a multi tool holder and an automatic knife exchange device, and a multi process processing is completed by one clip. A large amount of clamping time is saved. Because the manual operation is not needed, the closed or semi closed machining is adopted to make the human-computer interface clear, clean and coordinated. The interlocking ability of machine tools is strong, which can prevent accidents, improve operator's observation, operation and maintenance conditions, and set up emergency stop device to avoid accidents. All operations are concentrated on one operation panel, which is easy to operate at a glance.
