What Is a Variable Speed Lathe?

A lathe is a machine tool that uses a turning tool to turn a rotating workpiece. Drills, reamers, reamers, taps, dies and knurling tools can also be used on the lathe for corresponding processing.

Headstock: Also known as the headstock, its main task is to pass the rotational motion from the main motor through a series of speed-change mechanisms so that the spindle can obtain the different speeds of the forward and reverse steering. Pass the motion to the feed box. The spindle in the headstock is a key part of the lathe. The smoothness of the spindle running on the bearing directly affects the machining quality of the workpiece.

Ancient lathes were by hand or pedal

Ordinary lathe

The processing object is wide, and the adjustment range of the spindle speed and feed amount is large, which can process the inner and outer surfaces, end faces and internal and external threads of the workpiece. This lathe is mainly operated manually by workers, which has low production efficiency and is suitable for single-piece, small-batch production and repair workshops.

Turrets and turning lathes

It has a turret tool holder or a return tool holder capable of holding multiple tools, which can be used by a worker to complete a variety of processes by using different tools in turn in one clamping of the workpiece, which is suitable for batch production.

Automatic lathe

It can automatically complete the multi-step processing of small and medium-sized workpieces according to a certain program, can automatically load and unload, and repeatedly process a batch of the same workpiece, which is suitable for large-scale and mass production.

Multi-tool semi-automatic lathe

There are single-axis, multi-axis, horizontal and vertical. The single-axis horizontal layout is similar to that of ordinary lathes, but the two sets of tool holders are installed at the front, back, or top of the spindle, respectively, for machining discs, rings, and shafts. The productivity is 3 to 5 times higher than that of ordinary lathes.

Copying lathe

Can imitate the shape and size of the sample or the sample to automatically complete the processing cycle of the workpiece (see

The application of numerical control technology has not only brought revolutionary changes to the traditional manufacturing industry, making the manufacturing industry a symbol of industrialization, but also with the continuous development of the numerical control technology and the expansion of the application field, it has important effects on some important industries (IT, automotive , Light industry, medical care, etc.) play an increasingly important role, because the digitalization of equipment required by these industries is already a general trend of modern development. Current CNC lathes show the following development trends.

1 High speed and high precision

High speed and precision are the eternal goals of machine tool development. With the rapid development of science and technology, the upgrading of mechanical and electrical products has accelerated, and the requirements for the accuracy and surface quality of parts processing have become higher and higher. In order to meet the needs of this complex and changeable market, the current machine tools are developing in the direction of high-speed cutting, dry cutting and quasi-dry cutting, and the machining accuracy is also continuously improved. On the other hand, the successful application of electro-spindles and linear motors, ceramic ball bearings, high-precision large-lead hollow internal cooling, and ball nut forced cold low-temperature high-speed ball screw pairs and linear guide pairs with ball cages and other machine tool functional components The launch of the market also created conditions for the high-speed and precision development of machine tools. The CNC lathe uses an electric spindle, eliminating the links of belts, pulleys and gears, greatly reducing the moment of inertia of the main drive, improving the dynamic response speed and working accuracy of the main shaft, and completely solving the problems of belts and pulleys when the main shaft is running at high speed. Vibration and noise issues. The electric spindle structure can make the spindle speed reach more than 10000r / min. The linear motor has high driving speed, good acceleration and deceleration characteristics, and excellent response characteristics and following accuracy. The linear motor is used for servo drive, eliminating the intermediate transmission link of the ball screw, eliminating transmission gap (including backlash), small motion inertia, good system rigidity, and precise positioning at high speed, which greatly improves Servo accuracy. The linear rolling guide pair has zero friction in all directions and very small rolling friction, low wear, negligible heat generation, very good thermal stability, and improved positioning accuracy and repeatability. Through the application of linear motors and linear rolling guide pairs, the rapid movement speed of the machine can be increased from the original 10-20m / min to 60-80m / min, and even up to 120m / min.

2 High reliability

The reliability of CNC machine tools is a key indicator of the quality of CNC machine tools. Whether CNC machine tools can exert their high performance, high precision and high efficiency, and obtain good benefits, depends on their reliability.

3 CNC lathe design

Starting from the lathe processing technology, the drag and control of small and medium lathes have the following requirements: 1. To ensure economy and reliability, the main drag motor generally uses a cage asynchronous motor. In order to meet the requirements of the speed range, mechanical speed change is generally used. 2. The starting and stopping of the spindle motor should be able to realize automatic control. Generally, small and medium-sized lathes use direct start. When the motor capacity is large, YY-delta step-down start is commonly used. In order to achieve rapid stop, mechanical or electrical braking is generally used. 3. For turning threads, the spindle must be able to rotate forward and backward. For small lathe spindles, the forward and reverse rotation of the main motor is realized by the forward and reverse rotation of the main motor. When the main drive motor has a large capacity, the forward and reverse rotation of the main spindle is usually achieved by electromagnetic friction clutches. 4. In order to cool the tools and workpieces during turning, a cooling pump should be provided. The cooling pump only needs to rotate in one direction and has a chain relationship with the spindle motor. 5. The control circuit should be provided with the necessary safety protection and safe and reliable local lighting.

Machine tool

1) Trim the bottom surface of the cutter body to make the cutter body straight and stable. 2) Roughly grind the front so that the front is parallel to the bottom plane of the blade. 3) After rough grinding, the main cutting edge is parallel to the outer circle of the grinding wheel, and the blade body and the grinding wheel are inclined 60 -8. To form the correct main rake angle. 4) Based on the left plane of the knife body, the lathe grinds the rear of the left side of the knife body, while ensuring the auxiliary deflection angle and auxiliary rear angle. 5) The secondary back of the right side of the sharpening meets the following requirements: The center of the cutter head is used as the axis of symmetry to ensure the width of the main cutting edge. Ensure the length of the cutter head. Grind the secondary deflection angle and ensure the secondary back angle. 6) Refine the front and sharpen the chip flute. The lathe uses an open-type chip flute with a bevel and a wider angle to form a larger radius of chip waste, which is discharged to the same side in an orderly manner. The lathe should also guarantee the required front angle. 7) The chamfering of the main back and the transitional and cutting edges. ^[1]

1. Before turning on the lathe , first check whether the oil circuit and rotating parts are flexible and normal. Wear tight-fitting work clothes, fasten cuffs, wear protective caps for long hair, and do not wear gloves when cutting. Wear glasses when cutting workpieces and sharpening knives. 2. Check whether the equipment is normal when turning on the machine. The turning tool must be clamped firmly. The depth of the knife must not exceed the load of the device. The protruding part of the blade must not exceed 1.5 times the height of the blade. Safe position to prevent the turning tool from colliding with the chuck and loading and unloading large workpieces. When using a crane to load and unload workpieces, it is not allowed to remove the lifting gear without clamping the workpiece by the chuck, and all control power of the crane must be disconnected. After the workpiece is clamped, the spreader must be removed before the lathe is rotated. 3. When using abrasive cloth to grind the workpiece, use hardwood pads for the abrasive cloth, move the turning tool to a safe position, do not place tools and parts on the surface of the tool holder, and keep the needle tray secure. 4. Turning speed of lathe should be changed after stopping the turning of the lathe, so as not to hurt the gear. When driving, the turning tool should be close to the workpiece slowly, so as to avoid chipping to hurt people or damage the workpiece. 5. Lathe working hours can't leave the work place at will. It is forbidden to make jokes and jokes. When there is something to leave, you must stop and cut off the power. When working, you must concentrate your mind. You cannot measure the workpiece during the machine operation. The staff of the employment permit cannot operate the lathe alone. ^[2]