機械手(wo)-換刀機械手
機械手(wo)-換刀機械手,機械手,wo
數控機床潤滑系統(tǒng)控制的改進
機床潤滑系統(tǒng)的設計、調試和維修保養(yǎng)，對于提高機床加工精度、延長機床使用壽命等都有著十分重要的作用。但是在潤滑系統(tǒng)的電氣控制方面，仍存在以下問題：一是潤滑系統(tǒng)工作狀態(tài)的監(jiān)控。數控機床控制系統(tǒng)中一般僅設油箱油面監(jiān)控，以防供油不足，而對潤滑系統(tǒng)易出現的漏油、油路堵塞等現象，不能及時做出反應。二是設置的潤滑循環(huán)和給油時間單一，容易造成浪費。數控機床在不同的工作狀態(tài)下，需要的潤滑劑量是不一樣的，如在機床暫停階段就比加工階段所需要的潤滑油量要少。針對上述情況，在數控機床電氣控制系統(tǒng)中，對潤滑控制部分進行了改進設計，時刻監(jiān)控潤滑系統(tǒng)的工作狀況，以保證機床機械部件得到良好潤滑，并且還可以根據機床的工作狀態(tài)，自動調整供油、循環(huán)時間，以節(jié)約潤滑油。
1 潤滑系統(tǒng)工作狀態(tài)的監(jiān)控
潤滑系統(tǒng)中除了因油料消耗，油箱油過少而使?jié)櫥到y(tǒng)供油不足外，常見的故障還有油泵失效、供油管路堵塞、分流器工作不正常、漏油嚴重等。因此，在潤滑系統(tǒng)中設置了下述檢測裝置，用于對潤滑泵的工作狀態(tài)實施監(jiān)控，避免機床在缺油狀態(tài)下工作，影響機床性能和使用壽命。
1) 過載檢測 在潤滑泵的供電回路中使用過載保護元件，并將其熱過載觸點作為PMC系統(tǒng)的輸入信號，一旦潤滑泵出現過載，PMC系統(tǒng)即可檢測到并加以處理，使機床立即停止運行。
2) 油面檢測 潤滑油為消耗品，因此機床工作一段時間后，潤滑泵油箱內潤滑油會逐漸減少。如果操作人員沒有及時添加，當油箱內潤滑油到達最低油位，油面檢測開關隨即動作，并將此信號傳送給PMC系統(tǒng)進行處理。
3) 壓力檢測 機床采用遞進式集中潤滑系統(tǒng)，只要系統(tǒng)工作正常，每個潤滑點都能保證得到預定的潤滑劑。一旦潤滑泵本身工作不正常、失效，或者是供油回路中有一處出現供油管路堵塞、漏油等情況，系統(tǒng)中的壓力就會顯現異常。根據這個特點，設計時在潤滑泵出口處安裝壓力檢測開關，并將此開關信號輸入PMC系統(tǒng)，在每次潤滑泵工作后，檢查系統(tǒng)內的壓力，一旦發(fā)現異常則立即停止機床工作，并產生報警信號。
2 潤滑時間及潤滑次數的控制
為了要使機床運動副的磨損減小，必須在運動副表面保持適當的清潔的潤滑油膜，即維持摩擦表面之間恒量供油以形成油膜。但是數控機床運動副需要的潤滑油量不是太多時，采用連續(xù)供油方式既不經濟也不合理。因為過量供油與供油不足同樣是有害的、會產生附加熱量、污染和浪費。因此，潤滑系統(tǒng)均采用定期、定量的周期工作方式。
集中潤滑系統(tǒng)本身可以配置微處理器，專門用于設定潤滑泵停止的時間和每次供油時間，以控制潤滑泵間隙工作，設計人員往往也借此來簡化自己的PMC程序。
但機床在不同的工作狀態(tài)下，如剛剛通電初始工作階段、加工運行和因調整、檢測工件而使機床暫停運行時，機床對潤滑油的需求量各不相同。在配置FANUC數控系統(tǒng)的機床中，通常通過控制潤滑泵工作的時間來調節(jié)提供的潤滑油量，但是，習慣考慮的是潤滑系統(tǒng)在機床加工運行狀態(tài)下的供油方式，而沒有顧及其它工作狀態(tài)，這樣，當機床處于其它工作狀態(tài)時，潤滑系統(tǒng)所提供的潤滑油量要么不夠，要么過多。
機床導軌需要的潤滑油量近似可用下面公式計算：(長度+移動行程)×寬度×K。從公式中可以看出，機床導軌需要的潤滑油量與該導軌上的軸的移動距離有關。歐美生產的數控系統(tǒng)大多以行程量作為依據，來控制潤滑泵工作，間隙供油，并在系統(tǒng)中提供了相應的參數，便于機床制造商通過PMC程序對潤滑泵進行電氣控制。而在FANUC 0i系統(tǒng)中沒有類似的控制方法，為了能在配置FANUC 0i的數控機床上，采用近似的供油方式控制潤滑泵工作，我們改進了潤滑控制部分的電氣設計，讓控制系統(tǒng)能根據機床的具體工作情況自動調整潤滑泵工作頻率和每次的工作時間，在機床暫停時適當減少供油量，而機床初始工作時適當增加。
現將潤滑泵的工作狀態(tài)分成三類，分別設置潤滑泵工作時間和頻率。
1) 開機初始階段 機床開機，潤滑泵即刻開始工作，連續(xù)供油一段時間，此時潤滑泵工作的時間T1比正常狀態(tài)下的要長，以便在短時間內提供足夠潤滑油，使機床導軌上迅速形成一層油膜。潤滑泵運行時間由PMC程序中的TMRB指令設定。與TMR指令不同，由TMRB設定的時間，用戶不能隨意修改調整。
2) 加工運行階段 機床開機以后，經過空載運行預熱后，進入穩(wěn)定工作狀態(tài)。此后，控制系統(tǒng)控制潤滑泵間歇工作，以保證機床導軌能夠得到定期、定量的潤滑。潤滑泵每次工作的時間和其停止的時間由PMC程序中的TMR指令設定。TMR設定的時間參數，用戶可以在PMC數據窗口中根據需要適當調整。
3) 暫停階段 工件待加工或加工完畢時，機床往往處于暫停工作狀態(tài)，潤滑油的需求量相應減少，因此，需要及時調整控制方式，適當延長潤滑泵停止工作的時間，以減少其工作頻率，從而減少油品消耗。實現的關鍵是機床處于暫停狀態(tài)時，系統(tǒng)如何獲知。FANUC 0i數控系統(tǒng)中提供了信號MVX(F102.0)、MVY(F102.1)、MVZ(F102.3)，用于反映機床各軸的移動狀態(tài)。如果該信號狀態(tài)為“0”，表明相應機床軸靜止不動，如果所有移動軸均靜止不動，則表明機床此時處于暫停工作狀態(tài)。所以，只要上述所有信號狀態(tài)都為“0”，通過設計，PMC程序自動改變潤滑泵工作及停止時間。此時，潤滑泵工作的時間T2和停止的時間T3均使用TMRB指令設定，同樣，用戶不可以隨意修改這兩個時間參數。
3 潤滑報警信號的處理
1) 壓力異常 數控機床中潤滑系統(tǒng)為間歇供油工作方式。因此，潤滑系統(tǒng)中的壓力采用定期檢查方式，即在潤滑泵每次工作以后檢查。如果出現故障，如漏油、油泵失效、油路堵塞，潤滑系統(tǒng)內的壓力就會突然下降或升高，此時應立即強制機床停止運行，進行檢查，以免事態(tài)擴大。
2) 油面過低 以往習慣的處理方法是將“ 油面過低”信號與“ 壓力異?！眻缶盘枤w為一類，作為緊急停止信號。一旦PMC系統(tǒng)接收到上述信號，機床立即進入緊急停止狀態(tài)，同時讓伺服系統(tǒng)斷電。但是，與潤滑系統(tǒng)因油路堵塞或漏油現象而造成“ 壓力異?！钡那闆r不同，如果潤滑泵油箱內油不夠，短時間不至于影響機床的性能，無需立即使機床停止工作。但是，出現此現象后，控制系統(tǒng)應及時顯示相應的信息，提醒操作人員及時添加潤滑油。如果操作人員沒有在規(guī)定時間內予以補充，系統(tǒng)就會控制機床立即進入暫停狀態(tài)。只有及時補給潤滑油后，才允許操作人員運行機床，繼續(xù)中斷的工作。針對“油面過低”信號，這樣的處理方法可以避免發(fā)生不必要的停機，減少輔助加工時間，特別是在加工大型模具的時候。在設計時，我們將“ 油面過低”信號歸為電氣控制系統(tǒng)“ 進給暫?！鳖愋盘枺捎谩疤嵝选妗獣和?，禁止自動運行”的報警處理方式。一旦油箱內油過少，不僅在操作面板上有紅色指示燈提示，在屏幕上也同時顯示警告信息，提醒操作人員。如果該信號在規(guī)定的時間內沒有消失，則讓機床迅速進入進給暫停狀態(tài)，此時暫停機床進行任何自動操作。操作人員往油箱內添加足夠的潤滑油后，只需要按“循環(huán)啟動”按鈕，就可以解除此狀態(tài)，讓機床繼續(xù)暫停前的加工操作。
4 結語
數控機床電氣控制設計過程中，潤滑系統(tǒng)的處理若被忽視，對于機床的使用者而言，機床各部件能否定期定量得到潤滑，卻是十分重要的問題。應不斷改進、完善產品的設計，減少機床出現故障的次數，提高產品的可靠性。
The number controls the improvement that machine bed lubricate the system the control
The machine bed lubricates the design of the system and adjust to try with maintain to maintain, having got increases machine bed process accuracy, extension machine bed service life etc. very much the very important function.But in the aspects of electricity control that lubricate the system, still exsits below problem:An is to lubricate the system work appearance supervise and control.Number control the machine bed control system inside to establish generally and only the fuel tank oil supervise and control, the in order to prevent provides the oil the shortage, but to lubricate the system appear easily of leak the oil, oil road stop to wait the phenomenon, can't on time do the reaction.Two is a lubrication to establishes circulation with give oil time one, result in easily wasted.The number under the different work appearance control the machine bed, the amount of lubricant of the demand is different, such as in stage in pause in bed in machine compare an amount of lubricant for needing that process the stage want to be little.Aim at the above circumstance, in count control machine bed electricity control system, to lubricate to control the part proceeded the improvement designs, supervising and control the work condition of the lubrication system every moment, toing guarantee the machine bed machine parts get the good lubrication, and can also according to the work appearance of the machine bed, automatic adjust to provide the oil, circulation time, to economize the lubricant.
1 Lubricate the system the work the appearance supervise and control
Lubricate the system inside in addition to making the lubrication system provide the oil shortage because of the oil anticipates the depletion, fuel tank oil over little, familiar breakdown still contain oil pump expiration, provide the pipeline road stop, divide to flow the machine work falsely often, leak the oil to wait seriously.Therefore, establishes to descend to say the examination device in lubricate system, used for the work to pump to lubrication appearance puts supervise and control into practice to, avoiding the machine bed the work while lacking the oil appearance, affect the machine bed function with the service life.
1) Over carry to examine to used to carry to protect a dollar an importation for, combining its heat over carrying the order to be used as the system of PMC signal in power supply back track that lubrication pump, once lubricate the pump appeared to carry, the system of PMC can immediately examine and put paid to, make machine bed stopped the movement immediately.
2) The oil examines lubricant as the expendable goods, for this reason machine bed work after a period of time, lubricating pump lubricant inside the fuel tank will reduce gradually.If operate the personnel have no on time increase, be the lubricant inside the fuel tank arrive lowest oil, oil examination the switch acts immediately, combining to deliver this signal to PMC system the proceeding handles.
3) Pressure examination machine bed the adoption passes into the type concentrates lubrication system, only system work normal, each lubrication orders it can guarantee to get the pre-arranged lubricant.Once lubricate to pump oneself the work falsely often, lose efficacy, or is to provide to have in the oil back track a the place appears to provide the pipeline road stop, leak oil etc. circumstance, pressure in the system will present the abnormality.According to this characteristics, design at lubricate the pump to install the pressure examination switch exit, combine to input this switch signal into the PMC system, after every time lubricate pump work, check pressure in the system, once discover the abnormality then stop immediately the machine bed works, combining the creation report to the police the signal.
2 Lubricate the control between time and lubrication number of times
The in order to makes the machine bed exercise the vice- wear and tear lets up, must at exercise vice- surface keep appropriate and detergent lubricant , then maintain the friction surface an amount of provides the oil to become oil .But the number control the lubricant that machine bed exercise vice- demand the deal is not too many, adoption continue provide the oil method since uneconomical too not reasonable.Because too many to provide the oil with provide the oil the shortage similarly harmful, will produce the additional calories, pollution with wasted.Therefore, lubricate the system to all adopt the periodical and quantitative period the work the method.
Concentrate lubrication system oneself can install the microprocessor, used for exclusively the enactment lubricates to pump time of the ceasing with every provide oil time, lubricate pump cleft to work with the control, design the personnel to usually also borrow this to simplify own the procedure of PMC.
But the machine bed is under the different work appearance, such as just switch on electricity the beginning start the stage in work and process the movement similar to made machine bed pause circulated because of adjust, examination work piece, machine bed to lubricate the oily demand eachly not.In install FANUC number control the machine bed of the system, usually pass the control lubricates time that pump the work to provide to the amount of lubricant that regulate, but, what habit consider is to lubricates the system to process in the machine bed the movement appearance descend of provide the oil method, but did not have regard for the other the work the appearance, like this, crash the bed be placed in other work appearance, lubricate the system an amount of lubricant for providing want the 么 not enough, wanting the 么 excessive.
The machine bed leads the amount of lubricant of the demand look like and can use underneath formula calculation:( length+ move the route of travel) × width × K.Can see from the formula inside, the machine bed leads the lubricant of the demand measures to have something to do with should leading the axial ambulation distance of the 軌 .The number that Europe and America produce controls the system to measures with the route of travel mostly conduct and actions according to, control lubrication pump work, the cleft provides the oil, and provided the homologous parameter in system, the easy to machine bed manufactory pass the procedure of PMC to the lubrication pump proceed electricity control.But has no similar control method in FANUC a system, for the sake of can in installing a the 0 is of FANUCly the number controls machine bed, the adoption looks like of provide the oil method the control to lubricate to pump the work, we improved the lubrication the control part of electricity designs, letting control system can according to machine bed of concrete work the circumstance adjusts automatically lubrication pump work frequency with every work time, at machine bed pause hour appropriate the decrease provides the amount of oil, but appropriate increment for machine bed beginning to start work.
Will lubricate now the work appearance of the pump be divided into three type, establishes respectively lubrication pump work time with frequency.
1) The machine beginning that open the machine bed starts the stage opens the machine, lubricating the pump to begin to work right away, continuing to provide oil a period of time, lubricating at this time the time T1 that pump the work compares the normal appearance descends of want long, in order to provide the enough lubricant in the in a short time, make the machine bed lead the. the top become quickly a layer oil .Lubricate pump circulate time be set up by PMC TMRB in the procedure instruction.Different from the instruction of TMR, from time that TMRB set up, the customer can't modify the adjustment as one's pleases.
2) Processing the stage in movement machine bed opens the machine hereafter, passing by to get empty to transport the line prepare the hot empress, entering the stable work appearance.Henceforth, control system control lubricate the pump intermittent work, to guarantee the machine bed lead the can get periodical, quantitative lubrication.Lubricate time of the every work in pump to be set up by PMC TMR in the procedure instruction with time of its ceasing.Time parameter that TMR set up, customer can in PMC data window way according to need the appropriate adjustment.
3) Stage in pause a time for treating processing or processing completing, machine bed usually being placed in pause working appearance, lubricating oily demand cowgirl reducing, therefore, needing on time adjusting controling way, appropriate extension lubricating pumping stopping work, to reduce its work frequency, from but reduce the oil article the depletion.When key of realizing is a machine bed to be placed in the pause appearance, the system how to have learned that.The number of FANUC controled to provide the signal MVX( F102.0), MVY( F102.1), MVZ( F102.3) in the system, useding for reflecting machine bed each axial ambulation appearance.If the signal's appearance is a "0", express cowgirl machine bed stalk static motionless, if all ambulation stalk all static motionless, then express the machine bed to be placed in at this time pause work appearance.So, above only all signal appearance all for"0", pass the design, the procedure of PMC changes automatically lubrication pump work and stop time.This time, lubricate the time T2 that pump the work to use with the time T3 of the ceasing all the instruction of TMRB set up, same, customer must not modify these two time parameter as one's pleases.
3 Lubricate to report to the police the signal handles
1) Pressure excrescent the number controls to lubricate system as in the machine bed intermittent provide oil work method.Therefore, lubricate pressure in the system adoption periodical check method, at lubricate the pump the every work later on check.If appear the breakdown, if leaks oil, oil pump expiration, the oil road stops, lubricate the pressure in the system and then will descend or go up suddenly, this time should immediately compulsory the machine bed stops the movement, proceeding the check, in order to prevent the circumstances extends.
2) Oil over low handles habitually before the method is to report to the police with" pressure abnormality" the " oil over low" signal to signal to classify a type, be used as the urgent ceasing signal.Once the system of PMC receives the above signal, the machine bed enters the urgent ceasing appearance immediately, let servo system cut the power at the same time.But, with lubricate the system make the circumstance of the " pressure abnormality" different because the oil road stops or leaks the oil phenomenon, if lubricate to pump the oil inside the fuel tank not enough, short time affects the function of the machine bed not to the extent of, having no to need to make the machine bed stop the work immediately.But, after appearing this phenomenon, control system should on time show the homologous information, remind to operate the personnel on time increase the lubricant.If operate the personnel did not give complement in rule time, system will control the machine bed to enter the pause appearance immediately.Only have on time after supplying the lubricant, just allow to operate the personnel circulate the machine bed, continuing the work of the interruption.Aim at the " oil over low" signal, handles like this the method can avoid the occurrence the otiose shutting down, reducing the assistance processes time, especially at the time of processing the large molding tool.While designing, we classify the " oil over low" signal to electricity control system" enter to the pause" a signal, adoption" remind the —— the warning the —— pause, prohibition against auto circulate" of reporting to the police and handling way.Once oil inside the fuel tank over little, not only there is red instructioning in operating front-panel the light hint, in holding act but also show to warn the information at the same time, remind to operate the personnel.If that signal did not disappear in prescriptive time, then let machine bed entered in to give the pause appearance quickly, this time pause machine bed proceed any automatic operation.Operate the personnel toward fuel tank inside to increase the enough lubricant empress, a demand presses" circulate to start" button, can relieve this appearance, before letting the machine bed continue the pause process the operation.
4 Conclusion
Number control in the machine bed electricity control design process, lubricate the system handles if is neglected, for the user of the machine bed but speech, machine each parts of bed can periodical the fixed amount gets the lubrication, is a very important problem however.Should improve continuously, the design of the perfect product, reduce the number of times that machine bed appear breakdown, increase the dependable of the product.
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