Knowledge of machining center toolholder
May 09, 2022
Nowadays, CNC machine tools have been widely used in factories. These machine tools and tools come from all over the world with different models and standards.
The tool handle is the connector between the machine tool and the tool. The tool handle is a key link affecting concentricity and dynamic balance. It must not be regarded as a general component. Concentricity can determine whether the cutting amount of each cutting edge is uniform when the tool rotates for one cycle; When the spindle rotates, the dynamic imbalance will produce periodic vibration.
7: 24 refers to that the taper of the tool handle is 7:24, which is a separate conical positioning, and the conical handle is longer. The conical surface plays two important roles at the same time, that is, the accurate positioning of the tool handle relative to the main shaft and the clamping of the tool handle. Advantages: it is not self-locking and can realize rapid loading and unloading of tools; As long as the taper angle is machined to high precision, the connection accuracy can be ensured, so the cost of the tool handle is relatively low.
Disadvantages: during high-speed rotation, the conical hole at the front end of the main shaft will expand, the expansion will increase with the increase of rotation radius and speed, the taper connection stiffness will decrease, and the axial displacement of the tool handle will also change under the action of pull rod tension. After each tool change, the radial dimension of the tool handle will change, and there is a problem of unstable repeated positioning accuracy.
The tool handle is a key link affecting concentricity and dynamic balance. In the process of processing and production, the main shaft is not tightened in place, and the tool handle is not tightened. The possible causes of the failure are as follows:
1. Fatigue failure of some disc springs in the spindle automatic clamping mechanism.
2. The Latin position of the handle is wrong.
3. There are sundries in the taper hole of the main shaft.
The tool handle of the machining center cannot be pulled tightly. Check the above problems one by one. If the butterfly spring is found to be damaged, pay attention to the installation during replacement. The precautions are as follows:
1. Before installation, the interior of the main shaft must be cleaned and coated with new grease.
2. When installing the outer protective cover, pay special attention to the correct position of the four claws, and the upward direction must be consistent with the removal direction, which is related to the dynamic balance of the main shaft. In addition, the threaded through hole must be aligned with the threaded hole below before gently tapping the cover plate for assembly. If the flat square of the pull rod is not right, turn the pull rod with a wrench.
3. When installing the elastic knife signal next to the knife cylinder, pay attention to the combination to see whether the PLC signal is normal.
4. When installing the claw, be sure to tighten it. It is best to operate by two people when tightening the thread. One person uses a wrench to limit the flat side of the pull rod on the top, and the other person is tightening it. Remember not to use the spindle positioning limit to prevent the spindle positioning offset alarm caused by excessive force.
5. Finally, the upper tool shall be checked to see if there is any looseness, so as to ensure that there is no problem.
