What should pay attention to CNC lathe machining?
The processing technology of CNC lathes is similar to that of ordinary lathes, but since CNC is a kind of clamping and continuous automatic processing completes all turning processes, the following aspects should be noted.
1. Reasonable selection of cutting parameters
For efficient metal cutting, machining materials, tools and cutting conditions are the three main factors. These factors determine the machining time, tool life and machining quality. A cost-effective machining method must be a reasonable choice of cutting conditions.
的 Three factors of cutting conditions: cutting speed, feed and cutting depth directly cause tool damage. As cutting speed increases, the tip temperature rises, causing mechanical, chemical, and thermal wear. Increasing the cutting speed reduces the tool life by half.
的 The relationship between feed conditions and tool wear is small. But when feeding, the cutting temperature rises and wears after. It affects the tool less than the cutting speed. Although the cutting depth does not affect the tool as much as the cutting speed and feed rate, when the cutting depth is small, the hardened layer produced by the cutting material will also affect the tool life.
The user should select the cutting speed according to the material, hardness, cutting status, material type, feed amount, cutting depth, etc. The following table:
选择 Select the most suitable processing conditions based on these factors. The ideal state is regular and stable wear to reach life.
But in actual operation, the choice of tool life is related to tool wear, dimensional change, surface quality, cutting noise, processing heat and so on. When determining the processing conditions, research should be carried out according to the actual situation. For refractory materials such as stainless steel and heat-resistant alloys, coolants or hard blades can be used.
2. Select a tool
1) The teeth are thick. Choose a knife with high strength and durability to meet the requirements of thick teeth, large back knife and large amount of feed.
2) For precision turning, select high precision and durable tools to ensure the processing accuracy requirements.
3) In order to reduce the tool changing time and facilitate the tool alignment, the machine clamp knife and machine clamp knife should be used as much as possible.
3. Reasonable choice of fixture
1) Use universal fixtures to clamp the workpiece as much as possible, avoid using special fixtures;
2) The positioning reference of parts coincides to reduce the positioning error.
4. Determine the processing route
The machining route is the index of the movement path and direction of the tool relative to the part during the index control process.
1) Guarantee processing accuracy and surface roughness;
2) Shorten the machining route as much as possible to reduce the idle travel time of the tool.
5. Relation between machining route and machining allowance
At present, the conditions for universal use on CNC lathes have not yet been reached. Generally, the blank should be placed on the excess allowance, especially the allowance for the forging and casting hard skins. If it is necessary to use CNC lathe processing, then we must pay attention to the flexible arrangement of the program.
6. Points for Fixture Installation
At present, the connection between the hydraulic chuck and the hydraulic clamping cylinder is achieved by a pull rod. The critical point of the hydraulic chuck Chuck is as follows: First, remove the nut on the hydraulic cylinder, raise the hand, pull the tube, and extract the rear end of the slave shaft, and then raise the hand of the chuck fixing screw. Chuck can been deleted.
的 The polished edge on the tool refers to a small part of the blade, which is worn parallel to the tip along the sideways direction behind the blade. The blade is mainly used for secondary cutting after the cutting edge is cut, which is equivalent to removing scars such as burrs during the finishing process. The purpose is to improve the surface roughness of the workpiece, which is mainly used for the finishing of tools.