The machining process of CNC lathe is similar to that of ordinary lathe, but since the CNC lathe is a single clamping and continuous automatic machining to complete all turning operations, the following aspects should be noted:
1, Reasonable choice of cutting amount
For high-efficiency metal cutting, the material to be processed, the cutting tool, and the cutting conditions are the three major factors. These determine machining time, tool life and machining quality. A cost-effective processing method must be a reasonable choice of cutting conditions. The three elements of the cutting conditions: cutting speed, feed rate and depth of cut directly cause damage to the tool. As the cutting speed increases, the tip temperature rises, causing mechanical, chemical, and thermal wear. Cutting speed is increased by 20% and tool life is reduced by 1/2.
The feed condition is related to the wear behind the tool in a very small range. However, the feed rate is large, the cutting temperature rises, and the rear wear is large. It has less effect on the tool than the cutting speed. Although the depth of cut has no effect on the cutting speed and the feed rate, in the case of small depth cutting, the hardened layer is produced by the material to be cut, which also affects the life of the tool.
The user should select the cutting speed to be used according to the material to be processed, hardness, cutting state, material type, feed amount, depth of cut, and the like. The selection of the most suitable processing conditions is selected on the basis of these factors. However, in actual operations, the choice of tool life is related to tool wear, machined dimensional changes, surface quality, cutting noise, and heat processing. When determining the processing conditions, it is necessary to conduct research according to the actual situation. For difficult-to-machine materials such as stainless steel and heat-resistant alloys, a coolant or a rigid blade can be used.
2, A reasonable choice of tools
(1) When roughing the car, it is necessary to select a tool with high strength and durability to meet the requirements of large back feed and large feed amount during roughing.
(2) When finishing the car, it is necessary to select tools with high precision and durability to ensure the processing accuracy.
(3) In order to reduce the tool change time and facilitate the tool setting, the machine clamp and the machine clamp blade should be used as much as possible.
3. Reasonable selection of fixtures
(1) Try to use universal clamps to clamp the workpiece and avoid using special fixtures;
(2) The parts positioning reference coincides to reduce the positioning error.
4. Determine the machining route
The machining route is the movement track and direction of the tool relative parts during the index control machine tool processing.
(1) It should be able to ensure the processing accuracy and surface roughness requirements;
(2) The machining route should be shortened as much as possible to reduce the tool idle travel time.
5. The relationship between processing route and machining allowance
Under the condition that the numerical control lathe has not yet reached universal use, the excess margin on the blank, especially the margin containing the forged and cast hard skin layer, should be arranged on a common lathe. If you must use a CNC lathe, you need to pay attention to the flexible arrangement of the program.
6. Fixture installation points
The connection between the hydraulic chuck and the hydraulic clamping cylinder is realized by the tie rod. The main points of the hydraulic chuck clamping are as follows: the nut on the hydraulic cylinder can be removed by a wrench to remove the chuck. Turning is a method of cutting a workpiece on a lathe using a workpiece relative to the tool rotation. The cutting energy for turning machining is mainly provided by the workpiece rather than the tool. Turning is the most basic and common cutting method, and it plays an important role in production. Turning is suitable for machining rotary surfaces. Most workpieces with rotary surfaces can be machined by turning, such as inner and outer cylindrical surfaces, inner and outer conical surfaces, end faces, grooves, threads and rotary forming surfaces. The tools used are mainly turning tools.