After the accident:
I just compiled a macro program to try to process this newly ordered workpiece. I didn’t expect that the spindle would be stopped after this trial and collision. It is estimated that the disc-shaped shrapnel in the spindle was completely broken. If the disc is replaced If the shaped shrapnel is still deflected, it will be troublesome, and the maintenance cost is quite high, it is better to change the main shaft.
I can't escape the cost of changing the spindle. In the summer, it's rainy and rainy, and my old driver actually had a collision with mold and poking~~
This collision also learned a lot of knowledge.
First of all, let me popularize what parts the machine tool is composed of?
The mechanical structure of a typical CNC machine tool is mainly composed of basic parts, spindle transmission system, feed transmission system, rotary table, automatic tool changer and other mechanical functional components.
Basic parts mainly refer to large parts such as bed, column, worktable and spindle box. Plate welding materials are used except in special cases.
Today, not only did the knife crash, but the most important large spindle also stopped~~
Let’s take a look at what role the spindle plays in the machining process, and understand why changing the spindle is so expensive~~~
The main shaft bears the cutting force directly, and the speed range changes greatly.
Therefore, the following requirements are put forward for the main performance of the spindle assembly:
1. Rotation accuracy: refers to the radial and axial runout value of the working part of the front end of the spindle under the condition of no-load rotation. The measurement of rotation accuracy is generally divided into static measurement, dynamic measurement and indirect measurement. At present, most of our country still uses traditional static measurement in production.
2. Motion accuracy: refers to the rotation accuracy under working conditions. This accuracy is usually quite different from the low-speed rotation accuracy. The rotation accuracy in motion depends on the working speed of the spindle, bearing performance and the balance performance of the spindle itself.
3. Rigidity: refers to the ability of the spindle to resist deformation when subjected to external forces. Insufficient rigidity Under the action of cutting force, the spindle will produce large elastic deformation. It not only affects the processing quality, but also destroys the normal working conditions of the bearing and accelerates wear.
4. Vibration resistance: refers to the ability of the spindle to keep running smoothly without vibration during cutting.
5. Spindle temperature rise: When the spindle is running, excessive temperature rise will cause two adverse results. One is that the thermal deformation of the main shaft and the box directly affects the machining accuracy; the other is that the normal lubrication conditions of the bearing are damaged, affecting the normal operation of the bearing, and even "shaft holding".
6. Wear resistance: Only with sufficient wear resistance can the precision be maintained for a long time. Therefore, the key parts of the spindle (such as the taper hole of the spindle) must undergo good surface heat treatment.
From the above, you can see that the production process of the spindle assembly must be very strict. It not only requires good equipment, but also requires strict production management. The latter is precisely the weakness of Chinese enterprises.
