1. The structure of CNC lathe
The CNC lathe is also composed of a headstock, a tool post, a feed drive system, a bed, a hydraulic system, a cooling system,
The lubrication system and other parts are composed of only the essential difference in structure between the feed system of the CNC lathe and the feed system of the horizontal lathe.
The movement of the main shaft of the horizontal lathe is transmitted to the tool post through the hanging wheel frame, the feed box, and the slide box to realize the longitudinal and lateral feed motion.
The CNC lathe adopts a servo motor, which is transmitted to the slide plate and the tool post via the ball screw to realize the z-direction (longitudinal) and positioning (transverse) feed movement.
The CNC lathe also has the function of processing various threads, and the movement relationship between the rotation of the spindle and the movement of the tool post is controlled by the CNC system.
A pulse encoder is installed in the spindle box of the CNC lathe, and the movement of the spindle is transmitted to the pulse encoder 11 through the synchronous toothed belt. When the spindle rotates,
The pulse encoder sends out the detection pulse signal to the numerical control system, so that the rotation of the spindle motor and the cutting feed of the tool holder maintain the required thread processing
The kinematic relationship of, that is, the spindle rotates one revolution when the thread is processed, and the tool post moves the workpiece one lead in the z direction.
2. Layout of CNC lathe
The layout of the spindle, tailstock and other parts of the CNC lathe relative to the bed is basically the same as that of the horizontal lathe.
The layout of the tool holder and guide rail has undergone a fundamental change, because the layout of the tool holder and guide rail directly affects the CNC lathe
The performance and appearance of the village L bed J knot J and J. In addition, the CNC lathes are equipped with enclosed protective devices.
(1) The layout of the bed and guide rails. The relative position of the CNC lathe bed guide rail and the horizontal plane is shown in Figure 1-13. There are 4 layouts in total.
The horizontal bed has good craftsmanship, which is convenient for the processing of the guide rail surface. The horizontal bed with a horizontally arranged knife can increase the movement speed of the knife holder.
Generally, it can be used in the layout of large CNC lathes or small precision CNC lathes. However, the lower space of the horizontal bed is small, which makes it difficult to remove chips.
From the perspective of structural size, the horizontal placement of the tool post makes the horizontal dimension of the slide plate longer, thereby increasing the structural dimension in the width direction of the machine tool.
The horizontal bed is equipped with an inclined slide plate and is equipped with an inclined guide rail protective cover. On the one hand, it has the characteristics of good manufacturability of the horizontal bed;
On the other hand, the dimension in the width direction of the machine tool is smaller than that of the horizontally arranged slide plate, and the chip removal is convenient.
The layout of horizontal bed with inclined slide plate and inclined bed with inclined slide plate is generally adopted by small and medium-sized CNC lathes.
This is because these two layouts are easy to remove chips, chips will not accumulate on the guide rail, and it is also convenient to install the automatic chip conveyor; easy to operate,
It is easy to install the manipulator to realize single machine automation; the machine has a small footprint, simple and beautiful appearance, and is easy to realize enclosed protection.
The inclined angle of the inclined bed guide rail can be 30. , 45. , 60. , 75. And 90. (Called vertical bed) and so on. The angle of inclination is small,
Chip removal is inconvenient; the angle of inclination is large, the guiding of the guide rail is poor, and the force is also poor. The inclination angle of the guide rail will also directly affect the machine tool
The ratio of height to width of the outline dimension. Considering the above factors comprehensively, the inclination of the bed of the small and medium-sized CNC lathe is 60. Appropriate.
(2) The layout of the tool rest. The tool holder of the CNC lathe is an important part of the machine tool. The tool holder is used to clamp the cutting tools. Therefore, its structure is directly
Affecting the cutting performance and cutting efficiency of machine tools, to a certain extent, the structure and performance of the tool holder reflect the design and manufacturing level of CNC lathes.
With the continuous development of CNC lathes, the structure of the tool holder continues to innovate, but in general it can be roughly divided into two categories, namely the gang tool holder and
Turret type tool post. Some turning centers also use an automatic tool changer with a tool magazine.
The gang tool holder is generally used for small CNC lathes. Various tools are arranged and clamped on a movable slide plate, and the tool can be automatically positioned when changing tools.
The turret type tool post is also called a turret or a tool post, and it has two structures: vertical and horizontal. With multi-tool position automatic positioning device, through the turret head
Rotation, indexing and positioning to realize the automatic tool change action of the machine tool. The turret-type tool post should be accurate in indexing, reliable in positioning, and high in repeat positioning accuracy.
Fast indexing speed and good clamping ability to ensure the high precision and efficiency of the CNC lathe. Some turret turret not only can realize automatic positioning,
It can also transmit power. At present, two-coordinate linkage lathes mostly use a 12-station turret tool post, and also use 6-station, 8-station, and 10-station.
Turret type tool post. The layout of the turret-type tool post on the machine tool has two forms: one is the turret-type tool post for processing disc parts, and its rotary axis
It is perpendicular to the main shaft; the other is a turret-type tool post used to process shaft and disc parts, and its rotation axis is parallel to the main shaft.
The bed of a four-axis CNC lathe is equipped with two independent slide plates and a turret-type tool post, so it is called a double-tool four-axis CNC lathe.
Among them, the cutting feed of each tool post is separately controlled. Therefore, the two tool posts can cut different parts of the same workpiece at the same time, which expands
The processing range improves the processing efficiency. The four-axis CNC lathe has a complex structure and needs to be equipped with a special CNC system to achieve two independent
The control of the tool post is suitable for processing crankshafts, aircraft parts and other parts with complex shapes and large batches.