The limit setting of the CNC lathe should be clearly distinguished!
In order to ensure the safe operation of the CNC lathe, both ends of each linear axis are limited. The limit of CNC lathe can be divided into soft limit, hard limit and mechanical hard limit.
一, the hard limit
In the positive and negative limit positions of the servo axis, a limit switch or a proximity switch is installed. This is called a hard limit. The hard limit is the last protection of the servo axis overtravel, and the mechanical hard limit is reached after a short distance beyond the hard limit. Due to the high power of the servo system, once it hits the mechanical hard limit, it may cause damage to the machine, which is not allowed. Therefore, the result of the hard limit switching action is to cause an emergency stop.
When the feed axis moves beyond the stroke of the machine, the limit of the machine will work. The machine will alarm, causing the corresponding coordinate axes to continue to move during manual or handwheel operation. All axes will stop machining during automatic machining. At this point, we believe that the CNC lathe is a limit failure.
二, the soft limit
The software limit of the servo axis is the range of motion of the axis set by the machine parameters (1320, 1321 are axis type parameters) based on the machine reference point. If this range is exceeded, it is called the soft limit. The soft limit has no limit switch, only a set of position coordinate values.
三, the setting of the software limit parameters 1320, 1321
1. CNC lathe return to zero;
2. Manually move the coordinate axis to the desired soft limit point and record the machine coordinate value.
3. Write the coordinate values into the parameters, note that the unit is micron.
FANUC: P1320 and P1321 parameters (micron units);
SIMENS: 36100 and 36110 parameters;
GSK: 45-48 parameters (you can see the Chinese characters prompt).
The software limit parameters can only be modified after the parameters are unlocked!
四, the limit of the CNC lathe is lifted
To release the limit fault, first distinguish which type of fault belongs to, that is, the soft limit or the hard limit. The distinguishing method is the alarm information or the position of the observation feed axis.
1. Soft limit release: Generally, as long as the reverse direction of the overtravel axial overtravel is moved out of the overtravel area, press the reset button to cancel the alarm and the machine tool returns to normal.
2. Hard limit release: Generally, you need to press the “overtravel release” (“overtravel release”) on the machine while moving in the opposite direction. If the machine does not have a release button, you should try to move the screw in the opposite direction.
Note: At this time, press the emergency stop, otherwise the electric self-locking.