Electric control loop designs medium competition and adventurous issue

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Dispatch of net of machine tool of Chinese numerical control: Pass the example analysis of pair of competition in electric control loop and adventurous problem, announced of the problem concealment gender and the consequence that produce possibly, remind electric should cause to this problem from personnel of course of study enough take seriously, sum up experience in time, improve design principle, improve the dependability work efficiency of electric control system and quality. 0 foreword are electric in dominating return circuit if be put in competition and adventurous problem, can endanger man-machine security directly, cause grave accident, consequence is unimaginable, accordingly, height should be caused to take seriously in the design application of electric control loop. In the design of electronic circuitry, the problem of competition and adventure is in significant position, whether can because the existence of this problem is mattered to,the system work reliably. Additional, the electric control that makes as a result of strong report is compared commonly intuitionistic, know easily read, very few occurrence competition and adventurous problem, easy by negligence. If be in the design,the consideration does not control loop wiring mistake in process of week or production, overhaul, can produce this problem. After 1 circuit analyses soft starter to start electric machinery bypass to move, electric machinery freedom jockeys and delay time stops the control principle of machine to if the graph is shown 1 times,pursue, of electric machinery start to add up to implementation through the suction of auxiliary relay KA1; Start amount to fast hind auxiliary relay KA2 is sucked close, KM gets bypass contactor report, electric machinery bypass moves; When SB1 presses, coil of KA2, KM cuts off the power, electric machinery freedom jockeys; Should press when SB2, KT coil gets time relay report, often open contact to instantaneous closes and maintain oneself, till the delay time of KT disconnects often shut contact to open, cut off the power coil of KA2, KM, electric machinery stops. This loop does not have a problem from the analysis on control principle, but careful observation can discover delay time suspends loop existence issue. If KT uses auxiliary relay KA2 and time relay when the product of different type (use electromagnetism type relay like, another is electronic type relay) , differ as a result of coil movement time bigger, KA1 and KT are put in the problem of race against time on the movement, should press namely when SB2, KT gets report and maintain oneself, but often shut contact to open the instant when what KT delay time disconnects, the coil of KT cuts off the power, from the lock contact is opened, the delay time of KT disconnects to often shut contact to be met again instantaneous closes; In the often shuts contact to open instantaneous to close from delay time time that disconnects in KT delay time, if KA2 disconnects, criterion electric machinery can stop; Otherwise, electric machinery cannot delay time stops (because had not waited for KA2 to disconnect, the delay time of KT disconnects to often shut contact to close again, bring about KA2 to cannot cut off the power) . This kind of delay time jockeys to succeed sometimes, fail sometimes, its are to control loop to cannot work reliably as a result, it is typical competition and adventurous problem. If KT is relay of electronic type time (be like ST3PC-D) , and KA2 is electromagnetism type auxiliary relay (be like JZC3 -22 D) , at this moment, because KT always completes an action first, and KA2 is put in remanence as a result of coil again and release slower, cause KA2 to cannot cut off the power reliably. If instead of KT, KA2 same kind relay (the KT instead JSK4-224d in be like this) , can solve this kind of problem. Graph freedom of 1 electric machinery jockeys and delay time stops engine control principle. 2 improve blueprint 2 pursue to did not improve the contact ark before to dominate circuit. Graph 2 in, the hand in contact ark is moved, the frame type breaker of automata goes disappear designs blemish as a result of the principle, transfer switch is when automatic archives, competition and adventurous problem appear when owing line ball to encircle Q and X of coil closing gate to get report, cause breaker to cannot close gate reliably. To highlight main problem, other and will auxiliary loop skips, be in store can electric machinery already store can when, if 300# line gets report, owe line ball to encircle Q to be sucked first close, combine brake success automatically, fail otherwise, it is to cause namely add up to brake automatically to succeed sometimes, the reason that fails sometimes. Close gate to can make breaker reliable, delay time relay increases in circuit BSJ, if pursue,3 are shown. When 300# circuitry gets report, owe line ball to encircle Q to get electric start, x of coil closing gate passes relay of electrify delay time BSJ delay time is sucked electric start is gotten after closing, breaker closes gate. Graph 2 contact ark dominates circuit picture. Graph the 3 contact ark after increasing BSJ dominate circuit picture. The competition in electric control loop and adventurous problem have 3 epilogue to concealment certainly quality, in the design of electric control principle middling regular meeting is encountered, design personnel should consider carefully to control each detail of the principle, avoid the happening of this kind of circumstance. If be opposite,the control principle of new design exists doubt, best can pass test and verify of test on means. Anyhow, the competition in electric control loop and adventurous problem are endangered to man-machine safety great, want to avoid as far as possible. CNC Milling