Five-axis linkage five-axis linkage CNC machining center machine table can not return to zero fault diagnosis and repair

First, preparation before the repair
The structure and working principle of the CNC five-axis linkage CNC machining center rotary table (Fig. 1.2.60) are as follows: The CNC rotary table is mainly used for CNC boring and milling machines. Its shape is almost the same as that of the universal table, but its drive is The driving method of the servo system. It can be linked to other servo feed axes. Its feed, indexing and positioning lock are controlled by the given commands.
When the 5-axis linkage CNC machining center performs the indexing movement on the ratchet-type indexing table (ie, the rotary table), its working process is divided into three steps:
1. The indexing table is lifted.
2. Worktable rotary indexing.
3. Indexing table is lowered and positioned and clamped
Second, pre-research investigation
After the five-axis CNC machining center is turned on, there will be no emergency stop alarm, and the X, Y, and Z axes will be normal when returning to zero. When the B axis is zero, the alarm No. 2005 displayed on the LED of the machine system can be known. The AC contactor that controls the B-axis servo drive system is normally sucked.
Third, according to the analysis of the image, the cause of the list
According to the fault phenomenon, it can be inferred that the phenomenon of causing the five-axis linkage CNC machining center has the following points:
1. In the ladder diagram of the system, the work clamp clamping switch is in the wrong state, so that the worktable is still in the clamped state.
2. The B-axis drive motor burns out or the motor power line is broken.
3. B-axis bearing parts burn out.
4. The oil in the hydraulic tank is insufficient.
5. The hydraulic pump does not work or the hydraulic oil circuit has a broken circuit.
6. The hydraulic cylinder leaks.
Fourth, determine the relevant steps to troubleshoot.
According to the five-axis linkage CNC machining center machine maintenance guidelines and the above reasons, the troubleshooting steps are developed.
1. First check the status of the table clamp switch, 138.0 is "1" normal. When the table is manually released, 13.8.0 changes from "1" to "0", indicating that the table can be released.
2. Check that the oil in the hydraulic tank is in the normal range.
3. Check the oil pump to the oil circuit in the rotary table, there is no oil leakage.
4. After repeated tests, it was found that there is a problem with the hydraulic pressure of the five-axis CNC machining center table. The normal working pressure is 4.0~4.5MPa. When the workbench is loosened and lifted, the hydraulic pressure drops from 4.0MPA to about 2.5MPA. The pressure relief is severe, causing the workbench not to be fully lifted. After the release delay, the rotation cannot be performed, resulting in overload. After dismantling work, disintegration inspection found that the O-ring of the piston support ring has linear wear, its state can pass the pressure oil, the inner wall of the hydraulic cylinder is rough, the annular knife pattern is obvious, and the precision is too bad.
After replacing the hydraulic cylinder sleeve and the sealing ring, after re-installing and adjusting the test vehicle, the five-axis linkage CNC machining center runs normally and the fault is eliminated.