We often encounter the problem of random cutting in the tool magazine at work. Generally, this problem occurs accidentally, and it is difficult to judge the exact cause of the problem at high speed. Today, let's talk about the ideas for dealing with the problem of random cutting in the robot magazine:
The problem of random tooling in commonly used robot tool magazines can be roughly divided into two major reasons:
1. Cutterhead counting problem
1. During the rotation of the cutterhead, when iron chips fly into the counting switch and are sensed once, or the tool magazine counting signal terminal has poor contact, etc., the counting signal will be counted incorrectly, causing the current tool pocket number to be incorrect, resulting in random tooling.
Solution: If double counting switches are used, the two counting signals are compared every time. If one of the switches counts incorrectly, an alarm prompt will appear, which greatly reduces the failure of incorrect counting.
2. Due to sudden emergency stop or power outage during the rotation of the cutterhead, the cutterhead stops in the middle of the two tool pockets. If the power is interrupted during the forward rotation of the cutter head from tool holder No. 1 to tool holder No. 2, the tool holder stops at the middle position between tool holders 1 and 2. At this time, the counting signal does not count, and the current tool holder value is still 1. After turning on the machine, if you manually adjust the tool magazine position by pressing the tool plate reverse direction, the tool magazine tool holder rotates to position 1, but the current tool holder number is reduced by 1 and becomes 24 (24 tool magazines), causing random tooling. In the above situation, the reverse is also true.
Solution: If the last rotation state can be remembered when the power is off, it was running forward before the power off. After the system is restarted, the cutter head can only rotate forward and not reverse. At this time, the current tool pocket counting error will not occur, and vice versa. is also established.
2. Tool magazine data table refresh problem.
Because the manipulator tool magazine changes tools randomly, the tool table needs to be refreshed, that is, after the manipulator is replaced, the spindle tool number is exchanged with the current tool pocket tool number. The timing of exchange is very critical, and the timing of PLC exchange from each manufacturer is different. Some manufacturers exchange data on the tool arm 180 when detecting the tool clamping signal, some manufacturers exchange data after the tool arm returns to the tool, and some manufacturers exchange data on the signal when the tool sleeve is lifted.
I think that during the tool change process, when the tool arm is exchanged 180 degrees in place, it is the best time to refresh the data table. The tool arm is exchanged 180 degrees in place. If an alarm tool jam occurs at this time, the spindle unclamp solenoid valve will stop output and clamp the spindle tool. At this time, the spindle tool has arrived in the tool magazine pocket, and the tool in the tool magazine pocket has arrived on the spindle. , the data tables have also been exchanged. You only need to manually shake the robotic arm back, and there is no need to rearrange the tools. The shortcomings of data exchange at other times will not be described in detail here.
