The summary has stop to answer the phenomenon of whole pitch deviation below 0 means through the analysis, specific and computative the influence that answers 0 speed and link stopper length quickly, the reason that discovers deviation is formed finally and settle way. Pitch of link stopper of keyword bar case is answered in label of document of TG659 of graph classification date piles up B1. Axis of Y of machining center of breakdown phenomenon KVC 1400B winds reference point (also call at 0 o'clock) when, can produce the deviation of a pitch now and then, cause those who process work extremely easily to discard as useless to damage with the machine tool. 2. Y axis answers machining center of 0 methods KVC 1400B to use FANUC Oi-MA system, it is commonly used that its Y axis winds reference point link stopper winds 0 way. Answer zero sequential chart to pursue as follows, measure is ordinal for: Change the hand a place of ZRN of 0 selection signal " 1 " ; Choice Y axis and wind 0 feed way; When be close to link stopper, on the machine tool time 0 approach switch state by " 1 " change " 0 " , reference axis turns into FL low speed moves; When leaving link stopper, time 0 approach switch state by " 0 " change " 1 " , reference axis continues to move to order the around bar case that defines by 1850 parameter to the case of the first bar of coder with FL low speed place of deflection quantity Lsft stops; Affirmatory and current position is located in reach the designated position after area, give out Y axis reference point to return end signal ZP2 and Y axis to consult the position builds signal ZRF2. 3. Breakdown analysis answers 0 processes in, dial feed fold switch to 100% , when arriving at link stopper place to begin decelerate, y axis moves only to 0 o'clock 4mm, observe 302 diagnostic data, break away from decelerate link stopper to nod a distance to be controlled in 11200 μ M to case of the first bar; Dial fold switch to 10% , when beginning decelerate, y axis moves even to 0 o'clock 52mm, 302 diagnostic data show break away from decelerate link stopper to nod a distance to be controlled in 180 μ M to case of the first bar; Change fold for many times, discover a 0 rate are rapidder, the distance of axis of the Y when decelerate to zero float is shorter, the distance that breaks away from decelerate link stopper to be nodded to case of the first bar is longer. Because pitch of Y axis guide screw is 12mm, namely two bar case nods photograph adjacent the distance between is 12000 μ M, low speed returns zero hour 302 diagnostic data are very little, the A point that the specification approachs switch to leave link stopper and dot of B of point of case of the first bar are very close, when sometimes high speed answers 302 0 diagnostic data to be in 11200 around when, the bar case place that after showing slowdown, finds and low speed answer the 0 bar case that find to nod is not coder rotate the bar case point of same group. The phenomenon from observation and answer for many times 0 differ the result of a pitch, knowable Y axis is in after leaving decelerate link stopper, stop to be nodded in case of the first bar sometimes, stop to be nodded in case of the 2nd bar sometimes, this kind of circumstance happens in the graph normally 1 in the A point that approachs switch to leave link stopper and dot of B of point of case of the first bar are too close, a fast feed rate of 0 is too rapid or link stopper design is too short, y axis cannot arrive quickly from fast feed decelerate FL speed, the signal that switch condition is close to to retroflexion when leaving link stopper sparks through switch the defer of output, when NC gets this information finally, y axis had developed site of case of the first bar, position of the inactive when answering 0 ends is in point of point of case of the 2nd bar, cause for many times time 0 differred a pitch. For test and verify the correct errors of afore-mentioned judgement, first the influence of estimation speed, after breaking away from link stopper, with ideal FL rate moves, between point of case of bar of two photographs adjacent (coder turns circuit) the time of need: T=2400ms; When fold when 10 ％ , the speed after breaking away from link stopper and FL speed are very adjacent, it is from the time that breaks away from link stopper to nod expenditure to case of the first bar: T1=36ms. Answering 0 speed 15000mm/min and fold quickly when 100 ％ , grow not quite when link stopper, the effective rate after breaking away from link stopper is ambitious at FL speed, the time T1 that nods to case of the first bar so is less than 36ms far necessarily. Estimation is close to switch n to retroflexion signal transmits NC place to need time T2, the noise that T2 ≥ is close to switch is in season the defer time of a receiver of signal of 10 PLC input, common and adjacent the response of switch frequency is in normally 25 ～ 1000Hz, answer time to be 1 ～ 40ms about, according to the type of actual switch, choose intermediate value 20ms; FANUC system swings the receiver of signal to answer time to be 5 ～ 20ms with Yu Youzhen, choose intermediate value 12. 5ms, such T2 are in normally 32.
5ms left and right sides, the basis is close to the change with the different constant presence of switch and PLC interface, knowable zero hour is returned below 15000mm/min speed, because T1 is less than T2 probably, extremely incidental differ the result of a pitch. Again the influence of length of estimation decelerate link stopper, because Y axis is an index model add decelerate, FANUC system asks LDW of link stopper length satisfies next type: The VR in type -- definitely fast feed speed, set is worth 15000mm/minTR -- definitely fast feed adds slowdown time constant, set is worth 100ms TS -- servo time is invariable, length of link stopper of calculative of the type on 1/40s=25ms of ＝ of gain of ／ servo of computational value TS = 1 should be in 46.
5mm above, take no account of among them 20 ％ surplus, the shortest also must be in 38.
75mm, but the link stopper length of actual machine tool has 33mm only, link stopper design slants apparently short. 4. Trouble removal and conclusion change in inconvenience below the circumstance of link stopper, lower a 0 rate only, at the same time fine tuning blocks a position, the half that makes the 302 Ldec values of diagnostic date are close to case of bar of two photographs adjacent to nod a distance as far as possible (6000 μ M) , reduce for this definitely fast return 0 rate to 5000mm/min, adjust link stopper to make Lde. Show for 7200 μ M, original the question that answers deviation of 0 whole pitch is solved thoroughly. Link stopper winds 0 way is a 0 means that at present numerical control machine tool uses generally, as a result of what debug careless or of link stopper become loose wait for a variety of reasons, produce the breakdown that returns error of 0 whole pitch possibly, no matter use system of which kinds of numerical control, afore-mentioned means of settlements are applicable. CNC Milling
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