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Shield tunneling machine hydraulic system synchronization control Simulation Analysis
Hun Guoliang
Abstract:
A thrust hydraulic system of shield tunnellingmachine integration of p ressure and flow controlwas designed1Simulation
analysis of synchronizing thrust for thrust hydraulic system was carried out usingAMESim andMATLAB software1The simulation results
show that there are good synchronizing effects by app lying synchronization controlwith master2slave mode, and the synchronization precision can be controlled within ±1mm, which can p rovide the references for the shield tunnels。
Keywords: Shield tunnellingmachine；Thrust hydraulic system；Synchronization control；Simulation。.
Shield tunnellingmachine is a mechanical, electrical, hydraulic, measurement and control technology in the multidisciplinary integration, For the underground tunnel excavation of the major projects in technology-intensive equipment. It is excavating speed, high quality and labor intensity, high security, the right of surface subsidence and the environmental impact of small advantages, with the traditional method of drilling and blasting tunnel construction compared to the more obvious advantages, especially in complex geological conditions. a high water table depth of the tunnel and a larger, they can only rely on the shield. Propulsion system is the key to shield one of the main commitments of the entire shield jacking tasks required to complete Shield turning, The road curves, attitude control, and synchronous rectification campaign. Propulsion system to control Shield in overcoming the course of the advance encountered resistance on the premise that Driving under the process of construction, the various strata and soil changes in the earth pressure, to promote the right speed and pressure without advance-level coordination regulation, Shield tunneling makes the process as possible simultaneously to avoid unnecessary digging and less-digging To achieve control, Hydraulic System Requirements advance to the nonlinear variable load conditions and the pressure to achieve real-time control of volume, and require high reliability. Based on this, this paper to promote the hydraulic system synchronization control was related to simulation analysis.
1 Promoting an integrated design of hydraulic systems
Shield's hydraulic system is more complex, belonging to change load, high power, low flow applications. The system in the main oil pump along variable load-sensitive control; For six cylinder actuator will be divided into six groups, for a control to the completion of this progress, individual advancement or retreat. Double-forward or backward movements. All of a control module are the same, are proportional relief valve proportional valve, electromagnetic valve, auxiliary valve testing and related components and so on. Figure 1 hydraulic system to promote the work of a single diagram. Shield, the two-pass an electromagnetic valve power outages, system pressure oil ratio by two outflow valve, At this time three or four electromagnetic valve 9 Switch to state B position, the hydraulic cylinder piston rod 6 forward movement. Promote the process, the hydraulic cylinder 6 of displacement sensors embedded real-time detection of seven advancing displacement, Feedback converted into electrical signals proportional to the speed control valve proportional solenoid 2, Speed ratio control valve 2 throttle opening, thereby advancing the speed of the real-time control, At this point the system redundant flow from proportional relief valve 3 outflow. To achieve attitude, it is also necessary to promote real-time control pressure At this time the pressure sensor can detect five of the six cylinder pressure advance, Feedback converted into electrical signals proportional to the ratio of three relief valve electromagnet, 3 proportional valve control the throttle opening is to be achieved. The proportion of a relief valve 3 and proportional flow control valve and pressure sensor 2 5 7 and displacement sensor with the pressure flow Minute a control, real-time control propulsion systems driving speed and pressure.
Rapid regression, two-pass an electromagnetic valve in the power, short-circuit ratio valve 2, the system using a large flow of oil, At this time three or four electromagnetic valve 9 switched to a working state position, the hydraulic cylinder piston rod six rapid regression, Segment to meet assembly requirements.
Various sub-groups, 8 hydraulic lock and Y-type function of three or four electromagnetic valve 9 locking components together into a loop median may very well cease to prevent the leakage of hydraulic oil. Hydraulic cylinder returned, the balance valve four could play a role in stabilizing campaign.
2 promote multi-cylinder hydraulic system simulation
Cylinder the synchronous movement is very important, especially in the changing load shield equipment appear to be even more pronounced. Due to the special nature of the work Shield, Shield knife before the excavation site to the frequent load changes in straight forward cases, If we do not take the necessary synchronization measures to promote the process of setting Shield of deviation from the track, unnecessary or less dug-dug, it may even cause Shield poor equipment performance, failure or damage.
Propulsion system caused various hydraulic cylinder is not a synchronized for many reasons, mainly in the following aspects :
(1) Gain flow, the initial work current, linear zone differences, made the opening when a flow proportional flow control valve flow is not equal, with the result that when the hydraulic cylinder movement is not synchronous.
(2) hydraulic cylinder under different load, tunneling process Shield Cutter Face water pressure changes are random. Thus, all of a hydraulic cylinder to bear the load size, Carrying large hydraulic cylinder smaller than carrying hydraulic cylinder running slow.
(3) The hydraulic cylinder manufacture precision errors, leading to the Deputy Campaign hydraulic cylinder friction different; In addition, Installed with the deputy campaign gap, deputy campaign makes no equivalent friction. Friction large hydraulic cylinders running relatively slow.
Figure 2 promote multi-cylinder hydraulic system simulation model
Simulation of two hydraulic cylinder and the same speed as the input. Figure 3 and Figure 4 for the two symmetrical hydraulic cylinder pressure and the speed of simulation map. From the map you can see that since the two hydraulic cylinders suffered load, No.2 hydraulic cylinder pressure on the hydraulic cylinder than No.5 suffered some major atmospheric pressure. In addition, the No.2 hydraulic cylinder and viscous friction coefficient ratio No.5 hydraulic cylinder and viscous friction coefficient also, reflected in the speed has been different, force, viscous friction coefficient of hydraulic cylinder speed to advance more slowly, From Figure 4 advancing speed simulation curves, we can see that this time No.2 tank promoting stability in the rate of 36mm per minute. No.5 tanks and stability after the advance rate of about 39mm per minute.
Figures 5 and 6 for the two hydraulic cylinder displacement and displacement curves for the poor simulation curve. As the No.2 hydraulic cylinder No.5 advancing faster than hydraulic cylinder speed of the advance to the small, as time increases, two hydraulic cylinder displacement poor is also growing. Figure 6 shows that in the course of time to reach the 50's, the two hydraulic cylinder displacement of the poor to 215mm. In other words, every advance 1min, about 3mm of error, It may lead to the actual process of shield tunneling deviate from the pre-set trajectory. it is necessary to take immediate control strategy.
3 to promote multi-cylinder hydraulic system simulation analysis of synchronous control
now we often used hydraulic synchronous control in two major ways. One is the open-loop-control methods that use streaming manifold valve, synchronous cylinder, synchronous motors and other components synchronous hydraulic circuit, Its characteristics are the principle is simple and low cost, but also low accuracy. The second method is to use electro-hydraulic servo valves, or electro-hydraulic proportional valve components closed-loop control system, the adoption of this closed-loop control method, "the same way" and "master-slave" approach commonly used two control strategy using this control strategy is expected to be high-precision synchronization control requirements [7]. Simulation using master-slave synchronization control, No.2 hydraulic cylinder as the main hydraulic cylinders, hydraulic cylinder as No.5 from the hydraulic cylinder. No.2 hydraulic cylinder to the output of the ideal output No.5 hydraulic cylinder under control to track the selected ideal output and achieve.
Figure 7 for promoting multi-cylinder hydraulic system simulation AMESim synchronous model, Figure 8 Simulink was used to promote the construction of multi-cylinder hydraulic system simulation model synchronization. Simulation parameters obtained with the lack of synchronization control of the same, and two hydraulic cylinder speed input were the same. Given suffered load and hydraulic cylinder and viscous friction coefficient, to promote the process of hydraulic cylinder driving speed and displacement different. At this point, No.2 and No.5 two hydraulic cylinder displacement input to the S AMESim function, Then the output interface control structures Simulink simulation model. Simulation of the two-cylinder displacement of poor and the displacement settings, the differential displacement feedback signal to speed settings, compensation to achieve synchronization c
Figure 9 and Figure 10 using synchronous control of the hydraulic cylinder pressure and the speed of simulation curve. From the map you can see that two hydraulic cylinder pressure on the map with three no synchronization control measures adopted to promote the pressure curve, the there is no change. However, Figure 10 shows, this time from the two main hydraulic cylinder speed of the advance of basic coincidence, promoting the stability of both 36mm per minute speed.
Figure 11 and Figure 12 for two hydraulic cylinder displacement and displacement curves for the poor simulation curve. As the No.2 hydraulic cylinder speed of the advance and No.5 hydraulic cylinder speed of the advance of the same, So two hydraulic cylinder displacement of very similar. Figure 12 shows two hydraulic cylinder displacement of poor 01025mm only completely satisfy the control requirements.
?
4 Conclusion
This paper to promote a multi-cylinder hydraulic system to promote the simulation analysis, Comparing the absence of synchronization and the use of two simultaneous control of the simulation results. Simulation results show that the master-slave synchronization control strategy to achieve better propulsion systems simultaneously coordinated campaign Hydraulic cylinder can be controlled simultaneously accuracy of ± 1mm between actual Shield simultaneously provide a reference.
盾構推進液壓系統(tǒng)同步協(xié)調控制仿真分析
胡國良
摘要: 設計了一種基于壓力流量復合控制的盾構推進液壓系統(tǒng)。采用AMESIM和MATLAB仿真軟件對推進液壓系統(tǒng)同步協(xié)調控制進行了仿真比較分析。仿真結果表明采用主從式同步控制策略能夠達到很好的同步效果, 同步精度達到±1mm,為實際盾構同步推進提供了參考依據(jù)
關鍵詞: 盾構；推進液壓系統(tǒng)；同步控制；仿真。
盾構是一種集機械、電器、液壓、測量和控制等多學科技術于一體、專用于地下隧道工程開挖的技術密集型重大工程裝備。它具有開挖速度快、質量高、人員勞動強度小、安全性高、對地表沉降和環(huán)境影響小等優(yōu)點, 與傳統(tǒng)的鉆爆法隧道施工相比更具有明顯的優(yōu)勢, 尤其在地質條件復雜、地下水位高而隧道埋深較大時, 只能依賴盾構。推進系統(tǒng)是盾構的關鍵系統(tǒng)之一, 主要承擔著整個盾構的頂進任務, 要求完成盾構的轉彎、曲線行進、姿態(tài)控制、糾偏以及同步運動等。推進系統(tǒng)的控制目標是在克服盾構推進過程中遇到的推進阻力的前提下, 根據(jù)掘進過程中所處的不同施工地層土質及其土壓力的變化, 能夠對推進速度及推進壓力進行無級協(xié)調調節(jié), 使得盾構在掘進過程中盡可能達到同步推進, 避免不必要的超挖和欠挖。為
了達到控制要求, 推進液壓系統(tǒng)要求能夠在非線性變負載工況下實現(xiàn)壓力和流量的實時控制, 并要求具有高的可靠性?；诖? 本文對推進液壓系統(tǒng)的同步協(xié)調控制作了相關仿真分析研究。
1 推進液壓系統(tǒng)集成設計
盾構推進液壓系統(tǒng)比較復雜, 屬于變負載、大功率、小流量的應用場合。本系統(tǒng)在主油路上采用變量泵實現(xiàn)負載敏感控制; 對于6個執(zhí)行元件液壓缸, 將其分為6組, 進行分組控制, 以完成全推進、單個前進或后退、雙個前進或后退等動作。各個分組的控制模塊都相同, 均由比例溢流閥、比例調速閥、電磁換向閥、輔助閥及相關檢測元件等組成。圖1為推進液壓系統(tǒng)單個分組的工作原理圖。盾構推進時,二位二通電磁換向閥1 斷電, 系統(tǒng)壓力油經(jīng)比例調速閥2 流出, 此時三位四通電磁換向閥9切換到工作狀態(tài)B位置, 液壓缸6 的活塞桿向前運動。推進過程中, 液壓缸6 中的內置式位移傳感器7 實時檢測推進位移, 轉換成電信號反饋到比例調速閥2 的比例電磁鐵上, 控制比例調速閥2中節(jié)流口的開度, 從而實現(xiàn)推進速度的實時控制, 此時系統(tǒng)中多余的流量可從比例溢流閥3中流出。為了實現(xiàn)姿態(tài)調整, 還必須實時控制推進壓力, 此時可由壓力傳感器5 檢測液壓缸6 的推進壓力, 轉換成電信號反饋到比例溢流閥3的比例電磁鐵上, 控制比例溢流閥3的節(jié)流口開度來實現(xiàn)。分組中的比例溢流閥3和比例調速閥2與壓力傳感器5和位移傳感器7一起構成壓力流量復合控制, 可實時控制推進系統(tǒng)的推進速度和推進壓力。
快速回退時, 二位二通電磁換向閥1得電, 短路比例調速閥2, 系統(tǒng)采用大流量供油, 此時三位四通電磁換向閥9切換到工作狀態(tài)A位置, 液壓缸6的活塞桿快速回退, 以滿足管片拼裝的要求。
各個分組中, 液壓鎖8 與具有Y型中位機能的三位四通電磁換向閥9組成在一起成為鎖緊回路, 中位停止時可很好的防止液壓油的泄漏。液壓缸退回時, 平衡閥4能起到運動平穩(wěn)的作用。
2 推進液壓系統(tǒng)多缸仿真分析
多缸機構的同步運動十分重要, 特別是在變負載的盾構設備中顯得更為突出。由于盾構工作的特殊性, 盾構刀盤開挖面前方的負載經(jīng)常發(fā)生變化, 在直線推進的情況下, 如果不采取必要的同步措施, 推進過程中盾構將偏離設定的軌道, 引起不必要的超挖或欠挖, 甚至會造成盾構設備性能低劣、失效或損壞。
造成推進系統(tǒng)中各個分組液壓缸不同步的原因有很多種, 主要有以下幾個方面:
(1) 由于流量增益不同、起始工作電流不同、線性工作區(qū)有差異, 使得在某一開度時流過比例調速閥的流量不相等, 從而導致液壓缸運動時不同步。
(2) 液壓缸承受負載不同, 掘進過程中盾構刀盤工作面的水土壓力都是隨機變化的, 因此各個分組中的液壓缸承受的負載大小也不同, 承載大的液壓缸較承載小的液壓缸運行慢。
(3) 液壓缸的制造精度有誤差, 導致液壓缸運動副摩擦力也不同; 另外, 安裝時運動副的配合間隙不同, 使得運動副摩擦力也不相等。摩擦力大的液壓缸運行相對慢。
(4) 液壓系統(tǒng)安裝時油管長度和彎頭數(shù)目的不同也會造成液壓缸沿程阻力不相等; 此外, 長時間運行也會使得液壓缸的工作特性發(fā)生變化, 這些因素也會導致各個分組中的液壓缸推進時不同步[ 5 - 6 ]。基于此, 首先對沒有采取同步控制措施的左右對稱的2#和5#推進液壓缸進行仿真分析。模擬實際推進過程中分區(qū)液壓缸所受負載不同以及液壓缸所受內摩擦力的不同。仿真中把2#液壓缸的粘性摩擦系數(shù)設為1 ×104N /m / s, 負載中的彈簧剛度設為1 ×1010 N /m;而5#液壓缸的粘性摩擦系數(shù)則設為1 ×103N /m / s, 負載中的彈簧剛度設為5 ×109N /m。圖2為采用AMESim仿真軟件搭建的推進液壓系統(tǒng)多缸仿真模型圖。
圖2 推進液壓系統(tǒng)多缸仿真模型
仿真時兩個液壓缸的調速輸入設為相同。圖3和圖4為兩個左右對稱液壓缸的推進壓力和推進速度仿真圖。從圖中可以看出, 由于兩個液壓缸所受負載不同, 2#液壓缸所受壓力比5#液壓缸所受壓力約大2MPa。另外, 2#液壓缸的粘性摩擦系數(shù)比5#液壓缸的粘性摩擦系數(shù)也要大, 反映在速度上也有所不同,受力大、粘性摩擦系數(shù)大的液壓缸推進速度要慢些,從圖4推進速度仿真曲線可以看出, 此時2#缸穩(wěn)定后的推進速度為36mm /min, 而5#缸穩(wěn)定后的推進速度約為39mm /min。
圖5和圖6為兩個液壓缸的位移仿真曲線和位移差仿真曲線圖。由于2#液壓缸的推進速度比5#液壓缸的推進速度要小, 隨著時間的增大, 兩個液壓缸的位移差也越來越大。從圖6可以看出, 在推進時間到達50 s時, 兩個液壓缸的推進位移差達到215mm。也就是說, 每推進1min, 就有約3mm的誤差, 這樣很容易導致實際掘進過程中盾構偏離預先設定的軌線,因此有必要采取同步控制策略。
3 推進液壓系統(tǒng)多缸同步控制仿真分析
目前常采用的液壓同步控制方法主要有兩種。一種是開環(huán)式的控制方法, 即用分流集流閥、同步缸、同步馬達等組成同步液壓回路, 其特點是原理簡單,成本低, 但精度也較低。第二種方法是用電液伺服閥或電液比例閥組成閉環(huán)控制系統(tǒng), 采用這種閉環(huán)控制方法時, “同等方式”和“主從方式”是通常采用的兩種控制策略, 采用這種控制策略有望獲得高精度的同步控制要求[ 7 ]。仿真中采用主從式同步控制, 把2#液壓缸作為主液壓缸, 5#液壓缸作為從液壓缸。以2#液壓缸的輸出為理想輸出, 5#液壓缸受到控制來跟蹤這一選定的理想輸出并達到同步驅動。
圖7為推進液壓系統(tǒng)多缸同步仿真AMESim 模型, 圖8則為采用Simulink構建的推進液壓系統(tǒng)多缸同步仿真控制模型。仿真中所取參數(shù)與沒有采取同步控制時相同, 并且兩個液壓缸的調速輸入均相同。由于設定中所受負載以及液壓缸的粘性摩擦系數(shù)不同, 導致推進過程中液壓缸的推進速度和推進位移不同。此時, 把2# 和5# 兩個液壓缸的位移輸入到AMESim的S函數(shù)中, 然后通過輸出接口在Simulink中搭建控制模型進行仿真。仿真中把兩缸的位移差與設定的位移進行比較, 所得的位移差信號反饋到調速設定值上, 進行補償來達到同步控制。
圖9和圖10為采用同步控制的液壓缸推進壓力和推進速度仿真曲線圖。從圖中可以看出, 兩個液壓缸所受壓力與圖3沒有采用同步控制措施的推進壓力曲線相比, 兩者沒有發(fā)生變化。但從圖10可以看出,此時主從兩個液壓缸的推進速度基本重合, 穩(wěn)定后的推進速度均為36mm /min。
圖11和圖12為兩個液壓缸的位移仿真曲線和位移差仿真曲線圖。由于2#液壓缸的推進速度和5#液壓缸的推進速度相同, 因此兩個液壓缸的推進位移很接近。從圖12可以看出, 兩個液壓缸的推進位移差只有01025mm, 完全滿足控制要求。
4 結論
本文對推進液壓系統(tǒng)的多缸推進進行了仿真分析, 比較了沒有采用同步控制和采用了同步控制這兩種情況下的仿真結果。仿真結果表明采用主從式同步控制策略能較好地實現(xiàn)推進系統(tǒng)的同步協(xié)調運動, 液壓缸的同步精度可控制在±1mm之間, 為實際盾構同步推進提供了參考依據(jù)。
Ultra-high hydraulic angle O-ring seal the experimental study
Cui Yutao Du Cunchen
Abstract :
nitrile rubber O-ring EHV end Kok containers sealed imposed on containers so high hydraulic seal experimental series. The results show that angle enclosed structure, as well as O-ring compression rate, diameter, enclosed space, rubber hardness, The sealing surface roughness and seal the form and position tolerances, and other relevant factors reasonable match, strict control, the use of ordinary O-ring can be achieved 138MPa ultrahigh static hydraulic seal.
Keywords : EHV static O-ring seal
Along with the rapid modern industrial development, UHP increasingly widespread use of the ultrahigh-pressure killing Hill, super-high-speed refrigeration, Expanded food industry, supercritical fluid extraction, low-salt treatment, Expanded room temperature and high pressure compression fermentation and other typical applications. Such equipment is produced by the many advantages of increasing people's attention. If UHP food production is instantaneous pressure, role uniform, safe operation and low energy consumption to maintain good natural food color, smell and taste and nutritional characteristics of the components, with 21 new food simple, safe, natural, nutrition, health, and environmental protection in consumption demand. Which have significant social and economic benefits, has tremendous market potential and broad prospects for development.
However, China's current UHP food production industries badly need to improve the level of equipment, can produce economic, Energy-saving, safe and efficient handling equipment constrains EHV food processing technology marketing major bottleneck. Among them, how to create economic EHV containers and ensure that the high pressure seal containers is particularly difficult lie. UHV equipment can operate normally sealed to a large extent depends on the integrity of the structure. High pressure sealing device about the weight of the containers, weighing 10% to 30%. and the cost accounts for 15% ~ 40% of the total cost, design sealed pressure vessel design is an important component. Because many UHV equipment for space operations, the operation requires not only material can be quickly loaded fast again. and the frequent requirement in the open despite repeated achieve reliable sealing, General use of fast open-closed structure since the close of this problem can be resolved. Ordinary rubber O-ring seal structure is simple, convenience, low cost, compact installation, easy to use and has since closed closely role advantages, the industry is widely used. So experiment nitrile rubber (NBR) O-rings (32.5 × specifications for the 3.55G. implementation of the standards for GB3452.1-92) Kok sealed experiments.
1 O-ring seal from the Principle
1) state preload
O-ring sealed site after its general section by a certain amount of compression, as O-rings have good flexibility, the interface will have a certain degree of contact pressure, thus achieving preload under seal.
2) state
When the sealed chamber filled with hydraulic media, the role of media pressure, the O-ring to shift the low-pressure side, and the seal gap closed to live. With the increase of media pressure, the contact pressure has also been increasing, the peak is always greater than the fluid pressure. This will guarantee that the O-ring seal the sealing function, reflects the O-ring seal the ability to automatically sealed. Experience has shown that for ordinary rubber materials, generally 13 × 105Pa than the standard pressure.
2 the main parameters of Seal
O-ring seal effects and compression rate, diameter, enclosed space, rubber hardness, The sealing surface roughness and seal the form and position tolerances, and other factors are closely related. The impact of O-ring seal properties of various factors, as long as the parameters of a design will reduce the unreasonable results sealed, even result in seal failure. Now, therefore discuss the impact of specific factors to determine the value .
1）compression rate
After the O-shape link loads the seal spot, its section generally receives a quota the compression, because the O shape link has the good elasticity, docking touches personally meets has the certain contact pressure, thus realizes under the pre- tight condition seal.
2) active status
After the sealed chamber sufficiently enters the hydraulic pressure medium, in under the medium pressure function, the O shape link carries over a low pressure side, seals up the seal gap. Along with the medium pressure increase, the contact pressure also along with it increase, its peak value always is bigger than the fluid medium pressure. This has guaranteed the O shape packing ring seal function, also has reflected the O shape packing ring automatic sealing ability. The experience indicated that, regarding the ordinary rubber material, generally as the standard compares the pressure take 13×105 P a.
3) seal gap
O-ring gap in the high-pressure easily deformed easily be squeezed into the sealed space in order to cause damage, it is necessary to the O-ring seal gap to be strictly controlled. To prevent O-ring extrusion occurred, and to take into account the difficulty of installing and dismantling, The experimental space for the sealing of 0.1mm.
4) hardness
Elastic modulus small O-ring, the maximum contact stress small, extrusion capacity, easy to destroy. So when a high pressure, high hardness should use the O-ring. In this experiment the O-ring hardness IRHD (International Rubber Hardness levels), 80 ± 5.5) sealing surface roughness Seal the surface roughness is sealing technique to measure an important indicator. If the sealing surface Department has manufacturing defects or vertical scratch, it is very easy to seal leakage media. "Ultrahigh Pressure Vessel Safety Technology Supervision" provided EHV containers sealing surface roughness Ra should be less than or equal to 0 . 8 μ m. The experimental sealing surface roughness Ra from 0.4 μ m.
5) seals the form and position tolerances secret
Sealed cylindrical surface of roundness, cylindricity tolerance by eight precision selection Hole-face vertical axis of tolerance by seven precision selection.
3 experimental devices and airtight structure
（1）Experimental Device
1. Press flat under 2. Under plate 3. EHV four containers. 4.Pallets 5.O-ring 32.5 × 3.5 5-Ring 6.0 5.3 × 65 7. Cover 8. on the plate 9. Press plate 10. Stud 1 1. Arbors 12. Bolt 13. high-pressure pipe 14. connector nut 15. Nut
(2) sealing principle
When tighten bolts, which will help the upward movement of pallets compress O-rings, O-ring Close to the cone axis and the vessel wall. and the cone axis and the difference between forming ring seal belt, formed preload sealed. Operating in the state, with the media (the media to experimental pressurized water) pressure, the O-ring is compressed volume increases, contact pressure increased accordingly so as to achieve a reliable seal.
4 experiment
(1) O-ring uniform surface coating small grease. Cover and Arbors will use double-headed stud connection, and O-ring installed mandrels, Bolt pallets used to connect to the mandrels to compress O-ring;
(2) high-pressure pipe assembly, and the small joints nut nuts, Nut will joints and hydraulic media entrance of the threaded connection;
(3) under the pallets, containers and with the end caps on the map by a plate placed. Press access to power, two plate compactor next two pad; (4) access to power, preheat 5 minutes, Pressure relief valve rotation. 10 MPa to the differential pressure, pressure per-Level 5 minutes to observe any leakage;
(5) Records Expander pressure on the indicator values and the hydraulic fluid leakage.
5 experimental data loading sequence of records in table 1.
Hydraulic value
(MPa)
10
21
33
41
52
62
72
85
93
102
130
138
6 Results and Discussion
(1) several experiments show that, as long as a reasonable choice and strictly control the impact of the sealing performance of the main factors figure, Individual use of ordinary O-ring seal structure cone 138MPa can achieve a reliable seal;
(2) As laboratory equipment constraints, the experiment is just 138MPa hydraulic seal, O-ring seals that there is a potential to be tapped. This breakthrough of the traditional information that the O-ring seal maximum static pressure of 70MPa and when work pressure than Uniform Canada hubcap need to prevent extrusion of the limited space, it is worth further experiments.
(3) O-ring seal structure of cone-shaped O-ring seal and the corresponding surface of the manufacture of certain deviation compensation, This reduces the manufacturing of precision requirements, this seal structure should be promoted;
(4) O-rings in the completed several high pressure seal, found his appearance minor extrusion gap phenomenon. This shows that the O-ring is achievable 138MPa about EHV sealed But media pressure is required to consider increased use of O-rings with the triangular pad combination sealed structure or use other sealing pathways to solve, but this paper to explore the impact of sealing performance of the main parameters of methods, there is still a definite reference value. hubcap need to prevent extrusion of the limited space, it is worth further experiments.