Structure layout and characteristics of CNC lathes

 CNC lathes are also composed of headstock, tool holder, feed transmission system, bed, hydraulic system, cooling system, smoothing system and other components, only the feed system of CNC lathes and horizontal lathes in the feed system structure is essentially different. The movement of the spindle of the horizontal lathe is transmitted to the tool holder through the pulley frame, feed box and slide box to complete the longitudinal and transverse feed movement. CNC lathe is the selection of servo motor, through the ball screw to the skateboard and the tool holder, to complete the z (longitudinal) and azimuth (transverse) feed movement. The CNC lathe also has the function of various threads, and the motion connection between the spindle rotation and the tool holder movement is controlled by the CNC system. The CNC lathe headstock is equipped with a pulse encoder, and the movement of the spindle is transmitted to the pulse encoder through the synchronous gear belt. When the spindle rotates, the pulse encoder announces the detection pulse signal to the CNC system, so that the rotation of the spindle motor and the cutting feed of the tool holder maintain the motion connection required for machining threads, that is, when the machining thread is completed, the spindle rotates and the tool holder moves the workpiece to the guide.

The layout of CNC lathe spindle, tail seat and other components relative to the bed is common with the horizontal lathe base, and the layout of the tool rest and guide rail changes the base, because the tool rest and guide rail layout directly affects the function, structure and appearance of the CNC lathe. In addition, CNC lathes are also equipped with closed protective equipment. Bed and track layout. There are four ways to arrange the guide rail relative to the horizontal plane of CNC lathe bed. The horizontal bed has good manufacturability and is easy to process the guide surface. The horizontal bed adopts the horizontal equipment tool gun to improve the moving speed of the tool holder, which can generally be used for the layout of large CNC lathes or small fine CNC lathes. However, the small space under the horizontal bed makes it difficult to remove debris. From the perspective of structural scale, the horizontal placement of the tool holder makes the transverse scale of the slide longer, and then increases the structural scale of the width direction of the lathe. The layout of the horizontal bed is equipped with a slanted slide and slanted rail baffle. On the one hand, the horizontal bed has the characteristics of good technology; On the other hand, the width direction of the lathe is smaller than the width direction of the horizontal equipment slide, and the chip removal is convenient. The layout of the horizontal bed of the inclined slide and the inclined bed of the inclined slide have been widely used in small and medium-sized CNC lathes. This is because the two layout methods are simple to remove chips, chips will not accumulate on the guide rail, and it is also easy for the equipment to actively remove chips; Simple operation, simple equipment operation, can complete the initiative of single machine; The machine covers a small area, simple appearance, beautiful, simple closed protection.

The tool holder of CNC lathe is an important part of the lathe, the tool holder is used to clamp the tool, so its structure directly affects the cutting force of the lathe, and the structure and function of the tool holder reflect the planning and production level of CNC lathe to a certain extent. With the continuous development of CNC lathes, the tool rest structure is constantly innovative, but in general, it can be roughly divided into two categories, namely, row tool rest and turret tool rest. Some turning centers also use active tool changing equipment with a tool library. The tool holder is generally used for small CNC lathes, and various tools are placed and clamped on a movable skateboard, and active positioning can be completed when the tool is replaced. The tool rest, also known as the knife tower or the knife table, has two structural forms: vertical and horizontal. Using multi-tool position active positioning equipment, through the rotation, indexing and positioning of the tool holder, the active tool change action of the lathe is completed. The tool holder should be positioned accurately, reliably, repeatedly with high positioning accuracy, fast speed and good clamping to ensure the high precision and high power of the CNC lathe. Some tool holders can not only complete active positioning, but also transmit power. Now, the two-coordinate linkage lathe uses a 12-station turret tool holder, and also uses a 6-station, 8-station, and 10-station turret tool holder. There are two ways to arrange the turret tool holder on the lathe: one is the turret tool holder for machining disk parts. The axis of rotation is perpendicular to the main shaft; The other is a turret tool holder for machining shaft and disk parts, the axis of rotation is parallel to the main shaft.

The bed equipment of the four-axis CNC lathe has two independent skateboards and tool holders, so it is called the double-tool holder four-axis CNC lathe. At the same time, the cutting feed of each tool holder is separately controlled, so the two tool holders can cut different parts of the same workpiece together, which not only expands the processing scale, but also improves the processing capacity. The four-coordinate CNC lathe structure is messy, and it needs to be equipped with a special CNC system to complete the control of two independent tool rests, which is suitable for processing crankshaft, aircraft parts and other parts with messy shapes and large batches