Problems that should be paid attention to in the clamping of CNC lathes

The processing technology of CNC lathes is similar to that of ordinary lathes, but since CNC lathes are one-time clamping, all turning processes are completed automatically and continuously, so the following aspects should be paid attention to:

1. Reasonable selection of cutting amount

Whether the selection of cutting amount (ap, f, v) is reasonable plays an important role in whether the potential of the machine tool and the cutting performance of the tool can be fully utilized, and the realization of high quality, high production, low cost and safe operation is very important.

When rough turning, first consider selecting a larger back-cut amount ap, secondly choose a larger feed amount f, and finally determine a suitable cutting speed v. Increasing the back engagement amount ap can reduce the number of tool passes, and increasing the feed rate f is conducive to chip breaking. Therefore, selecting the amount of rough turning according to the above principles is beneficial to improve production efficiency, reduce tool consumption, and reduce processing costs.

When finishing turning, the machining accuracy and surface roughness are required to be high, and the machining allowance is small and uniform. Therefore, when selecting the cutting amount for finishing turning, we should focus on how to ensure the processing quality, and on this basis, try to improve productivity. Therefore, a small (but not too small) back-engagement amount ap and feed f should be selected during finishing, and a tool material with high cutting performance and reasonable geometric parameters should be selected to increase the cutting speed v as much as possible.

2. Reasonable choice of tools

1) When rough turning, a tool with high strength and good durability should be selected, so as to meet the requirements of large back cutting and large feed during rough turning;

2) When finishing turning, tools with high precision and good durability should be selected to meet the requirements of machining accuracy. ;

3) In order to reduce tool change time and facilitate tool setting, machine-clamped knives and machine-clamped blades should be used as much as possible.

3. Reasonable selection of fixtures

1) Try to use general fixtures to clamp the workpiece, and avoid using special fixtures;

2) The positioning datum of the parts is coincident to reduce the positioning error.

4. Determine the processing route

The machining route is the movement track and direction of the tool relative to the part during the machining process of the index-controlled machine tool:

1) It should be able to ensure the machining accuracy and surface roughness requirements;

2) The processing route should be shortened as much as possible to reduce the idle travel time of the tool.

5. The connection between machining route and machining allowance

At present, under the condition that the numerical control lathe has not yet reached the popular use, it is generally necessary to arrange the excessive allowance on the blank, especially the allowance containing the forged and cast hard skin layers, to be processed on the ordinary lathe. If it must be processed with a CNC lathe, it is necessary to pay attention to the flexible arrangement of the program.

6. Fixture installation points

At present, the connection between the hydraulic chuck and the hydraulic clamping cylinder is realized by a pull rod. The main points of hydraulic chuck clamping are as follows: First, remove the nut on the hydraulic cylinder with the wrench, remove the pull tube, and pull it out from the rear end of the spindle, and then remove the chuck fixing screw with the wrench to remove the chuck.