油田管材矯直機液壓系統(tǒng)設(shè)計
油田管材矯直機液壓系統(tǒng)設(shè)計,油田管材矯直機液壓系統(tǒng)設(shè)計,油田,管材,矯直機,液壓,系統(tǒng),設(shè)計
附錄1
故障診斷
液壓傳動系統(tǒng)由于其獨特的優(yōu)點，即具有廣泛的工藝適應(yīng)性、優(yōu)良的控制性能和較低廉的成本，在各個領(lǐng)域中獲得愈來愈廣泛的應(yīng)用。但由于客觀上元、輔件質(zhì)量不穩(wěn)定和主觀上使用、維護不當(dāng)，且系統(tǒng)中各元件和工作液體都是在封閉油路內(nèi)工作，不象機械設(shè)備那樣直觀，也不象電氣設(shè)備那樣可利用各種檢測儀器方便地測量各種參數(shù),液壓設(shè)備中，僅靠有限幾個壓力表、流量計等來指示系統(tǒng)某些部位的工作參數(shù)，其他參數(shù)難以測量，而且一般故障根源有許多種可能，這給液壓系統(tǒng)故障診斷帶來一定困難。
在生產(chǎn)現(xiàn)場，由于受生產(chǎn)計劃和技術(shù)條件的制約，要求故障診斷人員準(zhǔn)確、簡便和高效地診斷出液壓設(shè)備的故障；要求維修人員利用現(xiàn)有的信息和現(xiàn)場的技術(shù)條件，盡可能減少拆裝工作量，節(jié)省維修工時和費用，用最簡便的技術(shù)手段，在盡可能短的時間內(nèi)，準(zhǔn)確地找出故障部位和發(fā)生故障的原因并加以修理，使系統(tǒng)恢復(fù)正常運行，并力求今后不再發(fā)生同樣故障。
液壓系統(tǒng)故障診斷的一般原則
正確分析故障是排除故障的前提，系統(tǒng)故障大部分并非突然發(fā)生，發(fā)生前總有預(yù)兆，當(dāng)預(yù)兆發(fā)展到一定程度即產(chǎn)生故障。引起故障的原因是多種多樣的，并無固定規(guī)律可尋。統(tǒng)計表明，液壓系統(tǒng)發(fā)生的故障約90%是由于使用管理不善所致為了快速、準(zhǔn)確、方便地診斷故障，必須充分認(rèn)識液壓故障的特征和規(guī)律，這是故障診斷的基礎(chǔ)。
以下原則在故障診斷中值得遵循
（1）首先判明液壓系統(tǒng)的工作條件和外圍環(huán)境是否正常需首先搞清是設(shè)備機械部分或電器控制部分故障，還是液壓系統(tǒng)本身的故障，同時查清液壓系統(tǒng)的各種條件是否符合正常運行的要求。
（2）區(qū)域判斷根據(jù)故障現(xiàn)象和特征確定與該故障有關(guān)的區(qū)域，逐步縮小發(fā)生故障的范圍，檢測此區(qū)域內(nèi)的元件情況，分析發(fā)生原因，最終找出故障的具體所在。
（3）掌握故障種類進行綜合分析根據(jù)故障最終的現(xiàn)象，逐步深入找出多種直接的或間接的可能原因，為避免盲目性，必須根據(jù)系統(tǒng)基本原理，進行綜合分析、邏輯判斷，減少懷疑對象逐步逼近,最終找出故障部位。
（4）驗證可能故障原因時，一般從最可能的故障原因或最易檢驗的地方開始，這樣可減少裝拆工作量，提高診斷速度。
（5）故障診斷是建立在運行記錄及某些系統(tǒng)參數(shù)基礎(chǔ)之上的。建立系統(tǒng)運行記錄，這是預(yù)防、發(fā)現(xiàn)和處理故障的科學(xué)依據(jù)；建立設(shè)備運行故障分析表，它是使用經(jīng)驗的高度概括總結(jié)，有助于對故障現(xiàn)象迅速做出判斷；具備一定檢測手段，可對故障做出準(zhǔn)確的定量分析。
故障診斷方法
日常查找液壓系統(tǒng)故障的傳統(tǒng)方法是邏輯分析逐步逼近斷。
基本思路是綜合分析、條件判斷。即維修人員通過觀察、聽、觸摸和簡單的測試以及對液壓系統(tǒng)的理解，憑經(jīng)驗來判斷故障發(fā)生的原因。當(dāng)液壓系統(tǒng)出現(xiàn)故障時，故障根源有許多種可能。采用邏輯代數(shù)方法，將可能故障原因列表，然后根據(jù)先易后難原則逐一進行邏輯判斷，逐項逼近，最終找出故障原因和引起故障的具體條件。
故障診斷過程中要求維修人員具有液壓系統(tǒng)基礎(chǔ)知識和較強的分析能力，方可保證診斷的效率和準(zhǔn)確性。但診斷過程較繁瑣，須經(jīng)過大量的檢查，驗證工作，而且只能是定性地分析，診斷的故障原因不夠準(zhǔn)確。為減少系統(tǒng)故障檢測的盲目性和經(jīng)驗性以及拆裝工作量，傳統(tǒng)的故障診斷方法已遠(yuǎn)不能滿足現(xiàn)代液壓系統(tǒng)的要求。隨著液壓系統(tǒng)向大型化、連續(xù)生產(chǎn)、自動控制方向發(fā)展，又出現(xiàn)了多種現(xiàn)代故障診斷方法。如鐵譜技斷，可從油液中分離出來的各種磨粒的數(shù)量、形狀、尺寸、成分以及分布規(guī)律等情況，及時、準(zhǔn)確地判斷出系統(tǒng)中元件的磨損部位、形式、程度等。而且可對液壓油進行定量的污染分析和評價，做到在線檢測和故障預(yù)防。
基于人工智能的專家診斷系斷，它通過計算機模仿在某一領(lǐng)域內(nèi)有經(jīng)驗專家解決問題的方法。將故障現(xiàn)象通過人機接口輸入計算機，計算機根據(jù)輸入的現(xiàn)象以及知識庫中的知識，可推算出引起故障的原因，然后通過人機接口輸出該原因，并提出維修方案或預(yù)防措施。這些方法給液壓系統(tǒng)故障診斷帶來廣闊的前景，給液壓系統(tǒng)故障診斷自動化奠定了基礎(chǔ)。但這些方法大都需要昂貴的檢測設(shè)備和復(fù)雜的傳感控制系統(tǒng)和計算機處理系統(tǒng)，有些方法研究起來有一定困難，一般情況下不適應(yīng)于現(xiàn)場推廣使用。下面介紹一種簡單、實用的液壓系統(tǒng)故障診斷方法。
基于參數(shù)測量的故障診斷系統(tǒng)
一個液壓系統(tǒng)工作是否正常，關(guān)鍵取決于兩個主要工作參數(shù)即壓力和流量是否處于正常的工作狀態(tài)，以及系統(tǒng)溫度和執(zhí)行器速度等參數(shù)的正常與否。液壓系統(tǒng)的故障現(xiàn)象是各種各樣的，故障原因也是多種因素的綜合。同一因素可能造成不同的故障現(xiàn)象，而同一故障又可能對應(yīng)著多種不同原因。例如：油液的污染可能造成液壓系統(tǒng)壓力、流量或方向等各方面的故障，這給液壓系統(tǒng)故障診斷帶來極大困難。
參數(shù)測量法診斷故障的思路是這樣的，任何液壓系統(tǒng)工作正常時，系統(tǒng)參數(shù)都工作在設(shè)計和設(shè)定值附近，工作中如果這些參數(shù)偏離了預(yù)定值，則系統(tǒng)就會出現(xiàn)故障或有可能出現(xiàn)故障。即液壓系統(tǒng)產(chǎn)生故障的實質(zhì)就是系統(tǒng)工作參數(shù)的異常變化。因此當(dāng)液壓系統(tǒng)發(fā)生故障時，必然是系統(tǒng)中某個元件或某些元件有故障，進一步可斷定回路中某一點或某幾點的參數(shù)已偏離了預(yù)定值。這說明如果液壓回路中某點的工作參數(shù)不正常，則系統(tǒng)已發(fā)生了故障或可能發(fā)生了故障，需維修人員馬上進行處理。這樣在參數(shù)測量的基礎(chǔ)上，再結(jié)合邏輯分析法，即可快速、準(zhǔn)確地找出故障所在。參數(shù)測量法不僅可以診斷系統(tǒng)故障，而且還能預(yù)報可能發(fā)生的故障，并且這種預(yù)報和診斷都是定量的，大大提高了診斷的速度和準(zhǔn)確性。這種檢測為直接測量，檢測速度快，誤差小，檢測設(shè)備簡單，便于在生產(chǎn)現(xiàn)場推廣使用。適合于任何液壓系統(tǒng)的檢測。測量時，既不需停機，又不損壞液壓系統(tǒng)，幾乎可以對系統(tǒng)中任何部位進行檢測，不但可診斷已有故障，而且可進行在線監(jiān)測、預(yù)報潛在故障。
附錄2
Fault diagnosis
Hydraulic driving system because of its unique advantages, that is, has wide adaptability, good process control performance and relatively low cost, get more and more widely used in various fields. But because objectively yuan, auxiliary parts quality is not stable, and the subjective improper use, maintenance, and the components and working fluid in the system are within the closed oil circuit work, not as intuitive as machinery and equipment, also don't like electric equipment, can use various instrumentation easily measure various parameters, hydraulic equipment, only by a few to indicate that the system pressure gauge, such as some parts of the working parameters, other parameters are difficult to measure, and generally there are many possible fault source, which brings certain difficulty for the hydraulic system fault diagnosis.
At the scene of the production, due to the restriction of the production plan and technical conditions, the required fault diagnosis is accurate, simple and efficient fault diagnosis of hydraulic equipment; For maintenance personnel use of existing information and the scene of the technical conditions, as far as possible reduce the mounting workload, save time and cost of maintenance, with the most simple technology, in the shortest possible time, accurately find out the cause of the failure positions and failure and repair, make the system back to normal operation, and strive to the same failure will not happen in the future.
The general principles of the hydraulic system fault diagnosis
Correct analysis of the fault is the precondition of troubleshooting, most system failure, not sudden, before always have omen, when developing to a certain extent the failure omen. The cause of failure is various, there is no fixed rule can be found. Statistics show that the fault of hydraulic system of about 90% is caused due to poor management in order to conveniently, quickly and accurately diagnose faults, must fully recognize the characteristics and law of hydraulic fault, which is the basis of fault diagnosis.
The following principles in the fault diagnosis is worth following
(1) the first identifies the working conditions of the hydraulic system and the peripheral environment is normal need to first find out the mechanical parts of the equipment or the electric controlling part failure, or the fault of hydraulic system itself, at the same time find out whether the various conditions of hydraulic system in line with the requirements of normal operation.
(2) the judgment according to the fault phenomenon and the characteristics of certain areas related to the fault zone, gradually narrowing the scope of the failure detection element in this area, analysis of the causes, finally find out the specific fault.
(3) master fault types according to the phenomenon of failure in the end, make a comprehensive analysis step by step further to find the possible causes of a variety of directly or indirectly, to avoid blindness, must be based on the basic principle of the system, carries on the comprehensive analysis, logic, reduce suspicion gradually approaching, finally find out the fault position.
(4) validation may be the cause of the problem, from the most likely the cause of the problem or the most easily inspection place, so can reduce the workload, installation to improve diagnostic rate.
(5) fault diagnosis is based on the operation records and some system parameters. Set up a system running records, this is the scientific basis for the prevention, detection and troubleshooting; Set up equipment operation fault analysis table, it is the use of the height of the experience summarization, helps to quickly judge the problem; Have a certain detection means, can make a accurate quantitative analysis of the fault.
Fault diagnosis methods
Daily for hydraulic system fault is the traditional way of logic analysis approach.
The basic idea is comprehensive analysis, the condition judgment. The maintenance personnel by watching, listening, touching, and simple test and the understanding of the hydraulic system, from experience to determine the cause of the failure. When the hydraulic system failure, there are many possible fault source. Using logic algebra method, may be the cause of the problem list, and then one by one according to "after the first difficult logic, item by item, approximation, finally find out the cause of the problem and cause of failure of the specific conditions.
For maintenance personnel in the process of fault diagnosis has a basic knowledge of hydraulic system and strong analytical ability, can guarantee the diagnosis efficiency and accuracy. But the diagnosis process trival, must pass a large number of inspection, validation, and can only be qualitatively analyzed, the diagnosis of the cause of the problem is not enough accurate. To reduce the blindness of system fault detection and empirical and disassembling workload, the traditional fault diagnosis method has far cannot satisfy the requirements of modern hydraulic system. As the hydraulic system to develop in the direction of large-scale, continuous production, automatic control, appeared a variety of modern fault diagnosis method. Such as iron spectrum technology, can be separated from the oil of various grinding grain quantity, shape, size, composition and distribution rule, and so on and so forth, timely, accurately judge the degree of wear parts of the system components, form, etc. But also to the hydraulic oil pollution of quantitative analysis and evaluation, the online detection and fault prevention.
Based on artificial intelligence expert diagnosis system is broken, it through the computer imitation in there were experienced experts in the field of the method to solve the problem. Input fault phenomenon through the man-machine interface to computer, the phenomenon of computer according to the input as well as the knowledge in knowledge base, the causes of failure can be calculated, and then through the man-machine interface and output the reasons, and maintenance plans or preventive measures are put forward. Hydraulic system fault diagnosis method for such broad prospects, has laid a solid foundation of hydraulic system fault diagnosis automation. But most of these methods need expensive testing equipment and sophisticated sensing control system and computer processing system, some methods have some difficult, under normal circumstances is not suitable for field use. Here is a simple and practical method of hydraulic system fault diagnosis.
The fault diagnosis system based on parameter measurement
A hydraulic system work is normal, the key depends on two main working parameters namely whether the pressure and flow rate is in normal working condition, as well as the system parameters such as temperature and speed of actuator is normal or not. Hydraulic system failure phenomenon is various, the cause of the problem is also a combination of many kinds of factors. The same factors may lead to different fault phenomena, and the same fault may correspond to a variety of different reasons. For example: oil pollution may cause hydraulic system pressure, the flow or direction and so on various aspects of fault, which brings great difficulties to the hydraulic system fault diagnosis.
Method for measuring the parameters of the thinking of troubleshooting is that any of the hydraulic system working properly, the system parameters in the design and near the set value, the work if these parameters deviated from the target value, then the system will fail or likely to fail. The essence of a hydraulic system failure is the system working parameters changes. So when the hydraulic system failure occurs, is a certain element or some element has a fault in the system, further can be concluded that a point or some parameters in circuit has deviated from the target value. This shows that if the working parameters of hydraulic loop some point is not normal, then the system fault or failure may have happened to have occurred, to maintenance personnel immediately for processing. So on the basis of parameter measurement, and then combined with logic analysis, can quickly and accurately find the malfunction. Parameter measurement method can not only fault diagnosis system, but also can forecast the possibility of failure, and the prediction and diagnosis are quantitative, greatly improving the speed and accuracy of diagnosis. The test for direct measurement, detection speed, small error, detection equipment is simple, easy to use at the scene of the production. Suitable for any hydraulic system. Measurement, without downtime, and no damage to the hydraulic system, can almost any part of system testing, not only can diagnose has fault, and online monitoring, forecast the potential fault can be performed.
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