The machining center with knife fault analysis and processing
At present, the automatic tool change device processing center (ATC) there are two common types of tool change, one is the tool directly from the main shaft from the knife library exchange, 2 it is to rely on the manipulator to complete the spindle and the exchange of library on the knives.The first change knife style is suitable for the small processing center, knife library is small, the cutting tool is less, tool change simple, appear out a knife and other failure easily found and can be ruled out in time.The second mode of tool change, from the point of view of structure and action are one of the more complex.Based on Vcenter off knife - 80 type machining center as an example analysis fault phenomenon and processing.
1, machining center tool change action analysis
Look from the PLC figure this machine tool change procedure is more than 900 steps, it is difficult to understand how it works.Here, a little luck to ATC data exchange, transfer, storage and storage content such as knife, knife in action is briefly as follows: CNC tool change instruction (M06) - knife set down to fall in place, manipulator rotate and slow to turn in place (X4.7), spindle knife to loosen to loosen in position, manipulator rotate to turn the slowdown, arriving to the spindle blade clamping, clamping (X2.5) - manipulator reversal - in situ, mechanical tool change is complete.Among them, the manipulator of the fast and slow speed by frequency converter, motor rotates to drive the mechanical CAM transmission to realize rise and fall of the manipulator.
2, off fault
Knife fault phenomena appeared for a long time, to start with, the occasional time, once a month, or even two march time, thought it was caused by accidental factors, did not cause enough attention, slowly there once a week, or even two, accompanied by a knife is installed on the spindle does not reach the designated position.Then slowly evolved into a flight fail many times, seriously affect the production schedule, cause waste.Look carefully, knife there are two kinds of fault cases, one is by this work step processing after the completion of the knife, a step is this work isn't processing, cutting tool on the workbench.Perform movements due to machining process, tool change, action sequence is normal, so appear off knife, knife (loaded on the spindle) is not in place without any alarm phenomenon, only the operator in the workpiece inspection or hear out knife abnormal sound fault occurs, and sometimes on automatic processing production line, the phenomenon of the volume of waste due to falling knife.
3, fault analysis and processing
(1) check the manipulator ATC in knife troubleshooting steps, stop the manipulator in the vertical limit position.Check the manipulator arm two jaw and support jaw accessories such as spring.Were not found the problem, the manipulator clamping tool clamp, under the condition of manipulator rotate won't appear off phenomenon.
(2) check the tool clamping situation according to the main shaft jacket is not a knife phenomenon analysis, may be the main shaft hole ZhongDie spring not on tool clamping fastening, knife does not reach the designated position, appear thereby couldn't even put on and off phenomenon.Open spindle inside and found a few places for disc spring has broken.Then replaced all the disc spring.Trial run without any problems.Run a shift after appeared off phenomenon.
(3) check the tool change process for this failure only appeared in the process of change knife action, has nothing to do with other actions, edit a automatic tool change repeatedly execute a program, and run the program, in order to find the real reason for falling knife.Edit the automatic tool change program is as follows: the O0200 - S500 - M03 - G04X3. 0 - M06 - M99 - > %
In the program is running, the following findings: the spindle tool clamping did not reach the designated position, even without clamping action, manipulator, so off the knife.In accordance with the above change knife action sequence analysis of the spindle tool clamping in place of travel switch misoperation cause off fault.Open the PLC ladder diagram, to monitor the travel switch (input for X2.5), repeatedly for the trip switch, found that three times of more than 20 times pressing X2.5 for twice in the phenomenon of "0" state, and at the same time after pressing X2.5 cannot shifted from "1" state to state "0" phenomenon appears twice, according to the above damage to determine the travel switch.This switch for OMRONZC - Q2255, replaced with domestic CXW5-11 q1, and run normally.A week later, the operator still reflects a falling knife phenomenon, show the frequency of small, of course, this shows off the knife fault has not been completely ruled out.
(4) fault handling repeatedly run two hours, automatic tool change hundreds of times.Finally found a failure: in the case of a manipulator is not in place, the spindle tool to loosen, manipulator did not seize the knife, to appear off the knife phenomenon, which showed that the manipulator in place of magnetic induction switch misoperation.Replace the switch E2E - CR8C1, fault phenomenon still exists.Check the PLC ladder diagram, the switch input point as X4.7.X4.7 for normally open point in ladder diagram, when the induction switch status to "0", not induction status to "1".The logic state contrary to common induction switch logic state.When X4.7 break line, also can cause X4.7 as "1" state, so the screen X4.7 on-line, found in the rear of the electromagnetic induction switch terminals X4.7 loose, whenever the automatic tool change, manipulator CAM vibrations caused by a series of action, make X4.7 line is in off state, so that the manipulator arrived, loosen induction switch, though still induction tool, but because in a break state, X4.7 "to" 1 "state, so when the machine arrived, cutting tool to loosen and appear off fault.Fault off the knife, in this case is the cutting tool has work processing step and then drop the knife, in the above mentioned is the tool for any fault processing step work out a knife.
4, summary
Vcenter - 80 machining center knife failure, from the start of the fault, two months, once a month to fail many times, every shift back and forth after more than half a year, finally get solved., in a nutshell, the fault includes two cases: one is manipulator without knife is installed, the second is not catch the manipulator is loosen the knives.Although from dealing with the end result, is caused by a series of small fault, but could see through the above maintenance process, processing center failure, should be easy to difficult, after first SLATE cod croaker after Jane first, a fault a fault rule out step by step, not by finding a fault,