不同類型電磁溢流插裝閥的穩(wěn)壓特性研究

1、<p>　　本科畢業(yè)設(shè)計 (論文)</p><p><b>　　外文翻譯一</b></p><p>　　題目： 不同類型電磁溢流插裝閥</p><p>　　的穩(wěn)壓特性研究 </p><p>　　學(xué) 院： 機 械 工 程 學(xué) 院 </p><p&g

2、t;　　專 業(yè)： 機械工程及自動化 </p><p>　　班 級： </p><p>　　學(xué) 號： </p><p>　　學(xué)生姓名： </p><p>　　指導(dǎo)老師： </p><p&g

3、t;　　提交日期： 2013年 03月 12日 </p><p>　　不同類型電磁溢流插裝閥</p><p><b>　　的穩(wěn)壓特性研究</b></p><p>　　摘要：電磁溢流插裝閥廣泛應(yīng)用于高壓和溢流液壓系統(tǒng)中，其穩(wěn)壓特性直接影響液壓系統(tǒng)的動態(tài)響應(yīng)特性，通過實驗和模擬研究得到的電磁溢流插裝閥的穩(wěn)壓特性為其使用提供理論指導(dǎo)。</

4、p><p>　　關(guān)鍵詞：溢流閥　插裝閥　穩(wěn)壓特性</p><p><b>　　1.概述</b></p><p>　　電磁溢流插裝閥多和高壓泵出口，并且必須在正常、穩(wěn)定和有限壓力下工作，與此同時，它必須具有能夠快速達到系統(tǒng)的設(shè)定壓力和具有短時間內(nèi)御荷的功能。目前，在許多動態(tài)系統(tǒng)的各種電磁溢流插閥設(shè)計中，都有縮短其調(diào)節(jié)壓力時間的意向，通過實驗和模擬研究

5、，得到的不同類型的電磁溢流插裝閥的動態(tài)特性，為其系統(tǒng)的設(shè)計及其最優(yōu)化提供了理論基礎(chǔ)。</p><p>　　2.不同類型的電磁溢流插裝閥</p><p>　　2.1完整的電磁溢流插裝閥</p><p>　　圖１是完整的電磁溢流插裝閥的原理圖，圖2是電磁溢流插裝閥的實驗曲線圖，其中包括排量y，輸入信號s，液控溢流閥的入口壓力PD和主閥芯的入口壓力PA。從圖2可以看出，當

6、電信號傳遞到電磁閥上時，該閥的閥芯在300ms后開始移動，它就有一個確定的響應(yīng)時間。當液壓系統(tǒng)從御荷狀態(tài)轉(zhuǎn)換到溢流狀態(tài)時，液控溢流閥的入口壓力PＤ和主閥芯的入口壓力PＡ急劇上升直到達到溢流閥的預(yù)先設(shè)定壓力。因為阻尼R1降低壓力使得PＡ大于PＤ，從圖2，我們可以看到，其達到穩(wěn)定壓力的時間（從得到電信號開始到達到穩(wěn)定壓力）大概是1000ms。</p><p>　　圖2　完整電磁溢流閥的穩(wěn)壓測試曲線</p>

7、<p>　　2.2電磁換向插裝閥和溢流插裝閥的組合</p><p>　　電磁換向插裝閥和溢流插裝閥的組合方式如圖3所示，雖然采用可能更耗能，但益處多多。例如，這樣使得系統(tǒng)的正壓力誤差和壓力波動范圍很小；通過以上分析可知，動態(tài)孔R1是提升先導(dǎo)級穩(wěn)定性的核心部分。先導(dǎo)閥的粘性摩擦系數(shù)非常小。一些測試臺和測試閥的主要部件排列在桌面上。測試系統(tǒng)硬件有：移動泵，安全閥，測試閥，促動器，壓力傳感器和相關(guān)數(shù)據(jù)采集

8、處理設(shè)備。因為測試系統(tǒng)沒有負載，所以閥的流量是非常大的。因此，很難用流量計測試流量。在這個測試中，液壓促動器的速率用于計算流量。</p><p>　　孔R1的擴大影響先導(dǎo)級的阻尼比，通過以上模擬分析，有助于先導(dǎo)級直徑的沒計,又例如，這樣可以避免會影響系統(tǒng)穩(wěn)壓特性的電磁換向閥的內(nèi)部泄漏，因為電磁換向插裝閥的關(guān)閉時間很長，所以系統(tǒng)壓力的上升速度很慢。</p><p>　　為了解決這個問題，華中

9、大學(xué)自然科技學(xué)院設(shè)計了一種加速放大器用于縮短電磁閥的轉(zhuǎn)換時間，這在一定程度上可能縮短了調(diào)節(jié)壓力的時間，但這樣縮短其轉(zhuǎn)換的時間不可避免的在御荷時造成很大的壓力波動。相反的，當上腔面積保持不變時下腔面積改變，曲線如圖8所示，下腔面積的改變對閥的動態(tài)特性幾乎沒有影響，因為當下腔面積變大時，輸入流量沒有明顯的改變，因此，系統(tǒng)的上升時間增長。這些在傳遞函數(shù)圖中能夠看出，這意味著第二個第二階部分被一個比例部分替代。因為V０與兩個面積直接成比例，所以

10、幾乎不變大。</p><p>　　為了得到良好的調(diào)節(jié)壓力和減壓性能，把試用電磁方向閥轉(zhuǎn)換成電液比例閥（命名為改進的電液換向閥），如圖4所示?？焖夙憫?yīng)和使用外部先導(dǎo)控制油源的電液比例閥，不僅提升了調(diào)節(jié)壓力的速度，而且通過采用合適的閥芯能夠減少御荷的波動。為了驗證這一點，我們在實驗臺上進行了改進的電液比例插裝閥的實驗和電液換向插裝閥的實驗，如圖5所示。</p><p>　　圖3　電磁換向插裝閥

11、和溢流插裝閥的組合</p><p>　　圖4　改進的電液換向插裝閥和溢流插裝閥的組合</p><p><b>　　圖5　插裝閥試驗臺</b></p><p>　　電液換向閥的動態(tài)特性的實驗結(jié)果和改進的電液比例插裝閥的實驗結(jié)果如圖6和圖7所示。當輸入的是預(yù)壓力決定的最小閥比電磁鐵小。根據(jù)牛頓定律，由彈簧力和電磁力雙重作用的先導(dǎo)閥芯下降。在這個過程

12、中，先導(dǎo)壓力油通過閥口進入第二級閥的下腔，接著上腔的油流回油箱使第二級閥上升。當?shù)诙夐y上升時，彈簧的反饋預(yù)壓力變大，同時彈簧變大。受電磁力、反饋彈簧力和流力的作用，閥芯將會回到平衡位置。和電液換向插裝閥的測試曲線相比，改進的電液換向插裝閥的控制腔壓力PＣ平穩(wěn)無停滯的快速上升，其入口壓力PＡ和出口壓力PＢ的響應(yīng)時間只有30ms，這些都表明改進電液換向插裝閥的關(guān)閉特性不僅取決于液流壓力，外部先導(dǎo)控制油源也起著非常重要的作用，這樣才使得其時

13、間縮短3～5s鐘；另外，從轉(zhuǎn)換系統(tǒng)壓力PＡ（7.3MPa～12MPa）我們可知，改進的電液換向插裝閥和溢流插裝閥的組合系統(tǒng)達到穩(wěn)定壓力時間比電液換向閥和大流量閥的組合系統(tǒng)達到穩(wěn)定壓力時間快700ms。</p><p>　　圖6　電磁換向閥測試曲線</p><p>　　圖7　改進的電液換向插裝閥測試曲線</p><p>　　圖8是當主閥芯為DN80時，3種不同類型的電

14、磁溢流插裝閥的穩(wěn)壓模擬曲線圖，從此圖中我們可知：改進的電液換向插裝閥和溢流插裝閥的組合體的穩(wěn)壓時間（曲線1）是最短的，大概有200ms，電液換向插裝閥的溢流插裝閥的組合體的穩(wěn)壓時間（曲線2）是700ms，完整的電磁溢流插裝閥達到穩(wěn)定壓力所需的時間（曲線3）大概是900ms，改進的電液換向插裝閥和溢流插裝閥有最短的調(diào)節(jié)壓力時間和最小的壓力波動。因此，最后的二階組件要以簡化成一個比例組件。如果考慮第二閥的泄漏，圖中的整合元素可能被第一階的慣

15、性元素替代，因為先導(dǎo)和第二階中的小間隙和小泄漏的影響，它的自然頻率很高，和圖４中的第一階組成相比，第一階組成也能簡化成比例部分，所以整個閥的性能直接由先導(dǎo)閥決定。</p><p>　　而電磁溢流插裝閥的穩(wěn)壓能力很差并且壓力影響很大。由于液壓的存在電磁并不完美。</p><p>　　當輸入電流比確定值更大時，電磁的電壓曲線成線性。沒有使用位移電子反饋，主級段位移和輸入電信號的關(guān)系在機電轉(zhuǎn)化器

16、上為線性，所以流量反饋取其線性域的最小值。而且其剛度由主級位移決定。后續(xù)控制用于主級和第二級之間，第二閥的位移幾乎與主級相等。</p><p>　　通過對不同類型的電磁溢流插裝閥的動態(tài)特性進行實驗和模擬研究，得到改進的電液換向我裝閥和溢流插裝閥組合體的動態(tài)特性。使用外部先導(dǎo)控制油源時的溢流插裝閥最好，這樣不僅調(diào)節(jié)壓力快，而且具有良好的穩(wěn)壓能力。</p><p><b>　　3.結(jié)

17、論</b></p><p>　　通過對不同類型電磁溢流插裝閥的穩(wěn)壓特性的實驗和模擬研究,得到改進的電液換向閥和溢流插裝閥的組合體在使用先導(dǎo)控制油源時最佳的結(jié)論。這樣不僅系統(tǒng)調(diào)節(jié)壓力迅速，而且有很好的穩(wěn)壓特性。</p><p>　　Study on stabilized pressure characteristics of different type of the elect

18、romagnetic overflow cartridge valve</p><p><b>　　Abstract </b></p><p>　　The electromagnetic overflow cartridge valves are widely used in high pressure and large flow hydraulic systems

19、, and their stabilized pressure characteristics influence the dynamic response characteristics of hydraulic system directly. The research on stabilized pressure characteristics of different type of electromagnetic overfl

20、ow cartridge valves by experiment and simulation offers theoretical guidance for its use. </p><p><b>　　Keywords </b></p><p>　　Overflow valve, Cartridge valve, Stabilized pressure cha

21、racteristics </p><p>　　1 Introduction </p><p>　　The electromagnetic overflow cartridge valve is always applied to high pressure pump outlet, and it has functions of regulating, stabilizing and l

22、imiting pressure, at the same time, it must meet system characteristics of setup pressure quickly, unloading time shortly etc. At present, different kinds of electromagnetic overflow cartridge valves have come forth to s

23、horten pressure setup time in many hydraulic system designs. By experiment and simulation research, dynamic characteristics of differe</p><p>　　2 Different Type of the Elec- tromagnetic Overflow Cartridge Va

24、lves </p><p>　　2.1 The Integrated Electromagnetic Overflow Valve </p><p>　　Fig.1 is the schematic diagram of integrated electromagnetic overflow cartridge valve. Fig.2 is its experiment curves i

25、ncluding displacement y, input signal s, the inlet pressure of pilot relief valve Po and the inlet pressure of main spool PA. Fig.2 shows that when electrical signal is given to electromagnetic valve, the valve spool beg

26、in to move after 300ms, it has a certain response time. When the hydraulic system convert to overflow state from unloading state, the inlet pressure of pilot rel</p><p>　　2.2 Combination of Electromagnetic D

27、irectional Cartridge Valve and Overflow Cartridge Valve </p><p>　　Adopting combination of electromagnetic directional cartridge valve and overflow cartridge valve, as shown in Fig.3, the cost may increase in

28、 this way but profits are more. For one thing, deviation f pressure regulation and pressure variation range are small; From the above analysis, it can be seen that the dynamic orifice R 1 is the kernel component to incre

29、ase the stability of the pilot stage. Some major parameters of the test bench and test valve are listed in Table. The test system consists </p><p>　　The coefficient of viscous friction of the pilot valve is

30、very little, the introducing of the orifice R 1 increases the damping ratio of the pilot stage. Through simulation analysis, for the diameter of pilot stage designed in this paper, For another thing, it can avoid the int

31、ernal leakage in pilot electromagnetic directional valve which may influence stabilized pressure characteristics. Because the closing time of electromagnetic directional cartridge valve is long, the increasing speed of s

32、ys</p><p>　　To overcome this problem, Huazhong University of Science and Technology designed accelerated amplifier for electromagnetic valve to shorten it's switching time. It may shorten pressure setup

33、time in a certain degree, but the short switching time brings large pressure impact when unloading inevitably. To get good performance both pressure setup and pressure relief, change pilot Study on stabilized pressure ch

34、aracteristics of different type of the electromagnetic overflow cartridge valve electroma</p><p>　　Fig.6 and Fig.7 are respectively experimental results of dynamic characteristics for the electro-hydraulic d

35、irectional cartridge valve and the improved electro-hydraulic directional cartridge valve. when the input of the solenoid is larger than the smallest valve decided by the precompression force, according to the Newton pri

36、nciples, the pilot spool operated by the solenoid force and the spring force goes down. In this process, the pilot pressure oil comes into the lower chamber of the second v</p><p>　　Fig.8 shows that when the

37、 main spool is DN80, the stabilized pressure simulation curves of 3 different type of electromagnetic overflow cartridge valves. It is known from this diagram: the stabilized pressure time of. combination of the improved

38、 electro-hydraulic directional cartridge valve and overflow cartridge valve (curve 1) is the shortest, about 200ms, the stabilized pressure time of combination of the electro-hydraulic directional cartridge valve and ove

39、rflow cartridge valve (curve 2) is </p><p>　　While the integrated electromagnetic overflow cartridge valve has poor stabilized pressure ability and large pressure fluctuation. The solenoid is not perfect bec

40、ause the hysteresis exists. </p><p>　　But when the input current is lager than a certain value, the current-force curve of the solenoid is very linear. Without applying the displacement electro feedback, the

41、 relation between the displacement of main stage and the input current signal bear on the linearity of the electromechanical converter, So the precompression of the feedback spring should be set to the minimum of this li

42、near domain, and the stiffness is decided by the displacement of the main stage. The follow-up control is used </p><p>　　By experiment and simulation research on dynamic characteristics of different type of

43、electromagnetic overflow cartridge valves, obtain that the dynamic characteristics of combination of the improved electro-hydraulic directional cartridge valve and overflow cartridge valve using external control oil sour

44、ce are best, which not only regulates pressure rapidly, but also has good stabilized pressure ability. </p><p>　　3 Conclusions </p><p>　　Study on stabilized pressure characteristics of different