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中文翻译基于ADAMS仿真软件的液压支架四连杆机构的优化设计摘要：在设计一个大倾角的工作面液压支架时，提出了一种四杆连机构的结构特点,并使用ADAMS软件应用于四连杆机构的建模与仿真。为了达到最佳效果,实现参数化的建模和优化,设计结果要满足实际要求的才好。通过这种虚拟设计的方法，可以降低误差及其设计效率能得到有效的改善。关键词：液压支架；四连杆机构；优化设计；ADAMS仿真软件1.简介四连杆机构是掩护式液压支架或支撑掩护式液压支架至关重要的一个组成部分。它的功能有两个方面: 第一，帮助液压支架的立柱上升或降低，顶梁的前端差不多是垂直的上上下下移动， 如此可以在煤壁和顶梁的前缘之间保持一段差不多恒定的没有支撑的距离。对于顶板的控制来说，这是被广泛地认为非常合乎需要的一个特点。第二，液压支架要能承担更大的水平方向的载荷。在设计一个大斜倾角度的液压支架时，四连杆机构的优化设计是一个重要工作。四连杆机构的的尺寸直接影响液压支架的性能和地位。在传统的四连杆机构设计中，BASIC 程序被用于去计算设计，但是其结果经常不能满足设计要求，并且不能获得这个最佳的解决问题的办法。目前，ADAMS 软件被越来越多的广泛地在机械力学领域方面使用。因此，为了得到一个最佳的解决问题的设计办法，本文利用ADAMS软件建模和模拟四连杆机构的之间的关系。 2.四连杆机构的尺寸计算 2.1. 四连杆机构的结构特性 (1) 如图1所示，当液压支架从最底位置伸到最高位置时，其双纽线运动轨迹的最大宽度小于或等于70毫米，最好应该不到30毫米。 图1 四连杆机构结构特征(2)如图1四连杆机构结构特征所示，P角为顶梁与掩护梁之间的夹角，Q角是后连杆与水平线之间的夹角。P角与Q角应该满足以下要求。当支架伸到最高位置时，P5262，Q 7585。当支架在最低位置时，tanPW，根据摩擦学理论，它能使岩石落下地并且用掩护梁挡住岩石防止其落在工作区。钢材和岩石的摩擦系数W是0.3，即P=16.7。当支架在最低的位置时，为了保障安全性，P25才是合理的。在后杆底部和底座之间的有一段距离，Q2530。(3)如图1四连杆机构结构特征所示，角是水平线与从e1点到瞬时中心O的直线之间的夹角，e1点是掩护梁与顶梁连接的铰点。在支架的设计中，角应该满足的条件：tan 0.35，其直接影响支护的增量力。2.2.四连杆机构的尺寸计算；图2 四连杆机构参数1) 后连杆与掩护梁的长度计算如图2所示,如果H1被确定，掩护梁的长度： （1） 后连杆的长度（2） 前、后连杆上铰点之距为：（3） 前连杆上铰点至掩护梁上铰点之距为：F =GB（4） 如图3所示，在后连杆和坐标原点的在底部连接点之间的距离是E1。 图3 四连杆机构几何关系 2） 前连杆长度及角度的确定方法：b1的坐标当支架在最高位置时的计算高度为H1，此时b1点的坐标为： ( 5 ) ( 6 )b2的坐标支架在最低位置时的计算高度为H2，此时b2点的坐标为： （7） （8） 根据四连杆机构几何特征要求，支架降到最低位置时，Q22530。为了计算方便，令Q2=25。 （9）b3点坐标当支架的掩护粱与后连杆成垂直位置时，根据几何关系b3点的坐标为:（10） （11） （12） （13）c点坐标为前连杆的长度，因此，可以用圆的方程求得前连杆的长度。 （14）c点坐标是:（15）（16）c点坐标求出后，前连杆长度和角度就可以确定了。3) 前连杆下铰点的高度D和前、后连杆下铰点在底座上的投影距离E当前连杆c点坐标确定后，D和E的长度为：D=yc（17）E=E1xc (18 )对于大倾角的液压支架来说，当倾斜角度增大时，液压支架的重力线，或者对顶板的压力和自身重力将背离支架底座，那些将沿支架轴向方向的力，将产生翻转的一个力矩，导致支架倒下。根据几何学关系和力矩平衡状况，结论是要使支架不倒的情况为 Qr G。因此，煤壁的倾角a是决定液压支架不会倒下的因素。 (19)式中，Q是作用在顶板上的力，N是支架底座的宽度，H是支架的使用高度，h是支架质量的中心的高度。设计的大倾角的液压支架，它的最大支护高度为2600mm，支架的支护高度应满足在大倾角煤壁条件下的支架要求，支架的计算高度H1应该增加到2118mm。使用程序以倾斜射线作为目标函数，下面结果可以被获得。，.3.四连杆机构的尺寸参数优化 3.1.四连杆机构的建模和双纽线的模拟 ADAMS软件，即机械系统动力学自动分析，该软件是MDI公司开发的虚拟样机分析软件。通过程序可以计算和绘出如图2和实体尺寸，通过ADAMS软件可以建立四连杆机构的模型。选择中心点O为基准， 与x轴一致， 与y轴一致，如图4所示。图4 四连杆机构的简单模型模型建立以后，使用限制条件(关节)工具条加进连接点旋转对，和旋转工具 线加进连接点旋转对形成轮状的对和研磨连结点。最后既定的模拟条件，通过ADAMS/PostProcesser软件跟踪的e1点，它类似于双纽线轨迹如图5所示。图5 e1点的双纽线轨迹由于上述分析，这条双纽曲线轨迹不能满足设计要求。它应该考虑到角度对顶梁上的力和大倾斜角度的工作面液压支架的影响。降低支架的最大高度并且选择较小的角度的位置 ,选择垂直高度在927mm1673mm范围内的曲线，作为顶梁的前缘的运动轨迹。 3.2.四连杆机构的建模和最优化的参数确定因为考虑到计算的值并不是由模拟和分析引起的最佳的结果，最佳的设计连杆尺寸是由建模中的参数所获得，所以能满足设计要求的最佳的结果。在确定参数的建模期间，每个连接点被调整成为变量，并且每个变量的设计结果通过分析变量可以从中获得，如下表格1中所示。 表格1 设计结果设计变量设计点坐标原值（mm）精度（mm）优化结果（mm）11点Y367.34.426522点X421.91-2.347833点X981.960.461006.544点Y814.88-5.9835.25 55点X756.22-3.5829.40 66点Y1001.990.86102477点X-52.360.8612.10 88点X00.4410.2 99点Y00.375-9.58 观察设计变量在设计中的影响和范围。通过MSC.ADAMS/View软件提供各种图的解析作为研究报告，这包括设计变量的准确性。如上表格1所示的设计结果那样，点1，点2，点4，点6的灵敏度较大。这暗示着这4个变量对最优的结果影响也较大。设置4个准确性更加大的设计点， 采用ADAMS/PostProcesser软件一起改变每个设计点的曲线，然后通过比较并选出最优的分析结果。通过操作优化程序，四个设计点被优选出来得到最好的结果。最终四连杆机构的最优的实体尺寸通过分析和计算得到。 ，。通过ADAMS软件，根据计算的四连杆尺寸的模型，然后通过轨迹模拟分析各连接点，如下图6中所示。图6较完善的轨迹曲线 通过分析四连杆机构的尺寸优化的结果完全满足液压支架的设计要求。4. 结论 使用先进的ADAMS软件不仅取得四连杆机构模型的确定参数，运动轨迹模拟和最优化的大倾斜角的工作面液压支架的设计的参数，而且分析有关组成部分的运动状态。尽可能完善液压支架的优化设计，完全满足实际大倾角液压支架使在复杂条件下的最大要求， 因此基于ADAMS软件优化的结果证明液压支架的四连杆机构的最优化设计的可行性。 致谢感谢中国的第十一个五年计划里国家关键技术和计划的工程给予这篇文章的支持。参考文献1 毛耀华著，液压支架的四连杆机构计算机辅助设计，煤炭工业出版社，第06卷，2007年，第51-54页。2戴维斯，教长(犹他州大学) ,汉森，克雷格，机械工程师，基于ADAMS软件的风轮机建模的前景。3王国标，高荣，液压支架的双纽线运动学分析与优化方法，辽宁技术大学，第3卷的杂志，1991，第49-53页 . 4韩晓锋，胡邓高，凡讯等著，液压支架的四连杆机构的三尺寸的模型和动态的动画，煤炭工业出版社， 2006年9月，第67-68页 。5张安晋，大倾斜液压支架防护技术，第25卷，煤炭工业出版社， 2006年9月，第78-80页。毕业设计任务书任务下达日期： 20* 年 2 月 28 日毕业设计日期： 20* 年 3 月 7 日至 20* 年 6 月 10日毕业设计题目：中厚煤层支撑掩护式液压支架设计 毕业设计专题题目：毕业设计主要内容和要求：主要内容：支撑掩护式液压支架的设计：1、液压支架的绪论、原理、发展等；2、根据围岩性质、煤层赋存条件、初选配套设备的相关尺寸，确定支架基本架型及支架结构；液压支架的基本参数确定及其尺寸计算；3、液压支架的受力分析合强度校核 ；4、液压支架的设计。基本要求：工作阻力4000KN，最小高度1.7m，最大高度3.5m，中心距1.5。完成主要部件、组件及主要零件工作图的设计，编写完成整机设计计算说明；设计图纸量折合成A0图纸不少于3张，并完成设计说明书，要求说明书正文不少于70页,要有英文相关文章的翻译，翻译成中文后不少于3000字。院长签字： 指导教师签字：Optimization Design of Four-bar Linkage of Hydraulic Support Based on ADAMS Xin Zhang1,2, Jianwu Zhang1, Qingliang Zeng2, Hanzheng Dai2 1School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai, P. R. China 2College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao, P. R. China Abstract-In designing a large inclined angle hydraulic support, the structure characteristics of four-bar linkage is presented, and ADAMS software is applied to four-bar linkage modeling and simulation. In order to attain optimal results, parameterized modeling and optimization is achieved, and the design results meets the practical requirements very well. By means of this virtual design method, the errors can be reduced and design efficiency can be improved effectively. Keyword-hydraulic support; four-bar linkage; optimization design; ADAMS 1. Introduction Four-bar linkage is one of the most important components of shield-type hydraulic support or chock-shield-type hydraulic support. Its function has two aspects: One, as the support legs rises or lowers, the leading edge of roof beam moves up and down nearly vertically, thus maintaining a nearly constant unsupported distance between the coal wall and the leading edge of roof beam. This is a feature that is widely considered most desirable for good roof control. Second, it makes the support to be capable of bearing larger horizontal load. In designing of a large inclined angle hydraulic support, optimization of the four-link design is an important work. The size of four-bar linkage directly influences the performance and status of hydraulic support. In the traditional four-bar linkage design, BASIC program is used to compute 1, but the results often can not meet the design requirements and could not obtain the optimal solution. Currently, ADAMS software is more and more widely applied in the mechanical dynamics field 2. So, the paper makes use of the ADAMS software to model and simulate the four-bar linkage in order to achieve the optimal design solution3-4. 2. Dimension calculation of four-bar linkage 2.1. Structure characteristics of four-bar linkage (1)When the hydraulic support rises from the minimal to the maximal height, as shown in Fig. 1, the leading edge of roof beam the maximal horizontal movement distance of the leading edge of roof beam should be less than or equal to 70mm, the best should be less than 30mm. (2) As shown in Fig. 1, P is the angle between roof beam and shield beam, Q is the angle between back link and horizontal line. P and Qshould meet the following requirements. When the support is in the highest position, P5262, Q7585. When the support is in the lowest position, tan PW. It is to make the rock fall down and prevent the rock stay in the shield beam according to frictional theory. If friction coefficient W of the steel and the rock is 0.3, P=16.7. For sake of the safety, P25 is suitable when the support is in the lowest position. It should have a distance between the bottom of back link and bottom plate, Q2530. (3)As shown in Fig. 1, is the angle between horizontal line and the connection line from the link point 1eto the instantaneous center O, 1e is the link point between shield beam and roof beam. In the support design, should meet the condition:tan0.35, because angle directly influences the additional force of support. e1hPQoe=30 Figure 1. Structure characteristic of four-bar linkage 2.2. Calculating the dimension of four-bar linkage 2009 Second International Conference on Information and Computing Science978-0-7695-3634-7/09 $25.00 2009 IEEEDOI 10.1109/ICIC.2009.396338As shown in Fig. 2, 1H is the calculation height in the maximum position. Mathematically, the parameters of four-bar linkage is supposed that: o a2=A; ab=B; cb=C; cd=D; 2o d=E; 1ae=G; 1eb=F; 1Jo=S; 1Je=L;AIG=;1IGB=;tan=SL=U. Figure 2. Parameters of four-bar linkage 1)The dimension calculation of rear bar and shield beam As shown in Fig. 2, if H1 is determined, the length of shield beam is: 111sinsinHGPIQ=+ （ ）（ ） (1) The length of rear bar： AI G= (2) The distance between top link point of front bar and top link point of rear bar is: BIG=1 (3) The distance between top link point of front bar and top link point of shield beam is: FGB= (4) The distance between bottom link point of rear bar and origin of coordinates is1E, as shown in Fig. 3. Figure 3. Geometrical relationship of four-bar linkage 2)The dimension calculation of length and angle of front bar ? Coordinate of 1b point When the support is in the highest position1H, the coordinate of 1b point is: 11cosxFP=（ ） (5) 111sinyHFP=（ ） (6) ? Coordinate of 2b point When the support is in the lowest position2H, the coordinate of 2b point is: 22cosxFP=（ ） (7) 222sinsinyBP=（ ）+A（Q ） (8) When the support is in the lowest position,2Q2530, according to the geometric requirements. Mathematically, it is supposed that 225Q =. 2212212cosarctancosGEAQPEAQ+=+（ ）（ ） (9) ? Coordinate of 3b point When it is right-angle between shield beam and rear bar, the coordinate of 3b point is: 33cosxFP=（ ） (10) 333sinsinyBPAQ=+（ ）（ ） (11) 132221arctanarctan2EAPGGAE=+（） (12) 332QP= (13) ? Coordinate of c point 123cbcbcb=is the length of front bar. So the length of front bar can be calculated by use of the equation of circle. 2211ccCxxyy=+（） （） (14) The coordinate of c point is: 2222222231312323233131233123()() ()()2()() ()()cx x y yy yx x y yy yxx x y yy y x x + + = (15) )()()()(2)()()()(3213321332212321231323222322xxyyyyxxxxyyxxxxyyxxyc+= (16) The length and angle of front bar can be calculated after determining the coordinate of c point. 3) The calculation of the height D of the front bar bottom link point, and the projective distance E on the base between bottom link point of front bar and bottom link point of rear bar After calculating the coordinate of c point, the length D and E is: cDy= (17) 339 1cEEx= (18) For large inclined angle hydraulic support, when the angle increases, the gravity line of hydraulic support, or the roof pressure and gravity force will deviate from the support base, The support will spin axially, acted by the resultant torque, so that the support overturns. According to the geometric relationship and the torque balance conditions, the conclusion is drawn that the non-overturn condition is QrGs5. So, the inclined angle of coal seam is deduced that the support couldnt overturn. +=hNHQNQarctan (19) Where, Q is the pressure on the roof, N is the width of the support base, H is the usage height of the support, h is the height of gravity center of the support. In designing a large inclined angle hydraulic support, the maximum support height is 2600mm. The support height should be increased in order to meet the design requirements of hydraulic support in deeply inclined coal seam, the calculation height H1 increases to 2118mm. By use of the program that sloping line is thought as the objective function, the below result can be obtained. tan= 0.338, Q1= 75.10, Q2= 29.98, P1= 59.96, P2= 15.09, A= 988.78mm, B= 295.56mm, C= 995.82mm, D= 367.30mm, E= 421.91mm, G= 1343.45mm. 3. Parameter optimization of four-bar linkage size 3.1. Four-bar linkage modeling and lemniscates trajectory simulation ADAMS, Automatic Dynamic Analysis of Mechanical Systems, is the virtual prototype analytical software developed by MDI. According to Fig. 2 and the physical dimension calculated by program, the four-bar linkage is modeled by means of ADAMS/view. The center O point is chosen as the basis, 2o d coincides with x axis is, cd coincides with y axis, as shown in Fig. 4. Figure 4. Simplified model of the four-bar linkage After modeling, rotating pair (Revolute) is added in the link point by use constraints (Joints) toolbar, and the rotating driver is added in the revolute pair of o a2 and ground link point. Finally setting the simulation conditions, the track of e1 point is drawn by ADAMS/PostProcesser. It is similar to lemniscates trajectory as shown in Fig. 5. Figure 5. lemniscates trajectory of e1 point From the above analysis, this lemniscates trajectory can not meet the design requirement. It should be considered that angle influences the additional force of roof beam and large inclined angle influences the hydraulic support. To reduce the maximum height of support and choose the poison of small angle , the curve is chosen that the scope of vertical height is 927mm1673mm as motion trajectory of the leading edge of roof beam. 3.2. Four-bar linkage parameterized modeling and optimization Because the linkage size parameter that calculated in computational program is not the optimal result by simulation and analysis, optimally designing the linkage of should be parameterized modeling so as to obtain the optimal result that meet the design requirement. During parameterized modeling, every link point is set to variable, and the design result of every variable is gotten by analyzing the variables, as shown in Table 1. Table 1. Design results Design VariableDesign Point Coordinate Initial Value (mm) Sensitivity(mm) Optimized Significance(mm) DV_1 POINT_1Y 367.3 4.4 265 DV_2 POINT_2X 421.91 -2.3 478 DV_3 POINT_3X 981.96 0.46 1006.5 DV_4 POINT_3Y 814.88 -5.9 835.25 DV_5 POINT_4X 756.22 -3.5 829.40 DV_6 POINT_4Y 1001.99 0.86 1024 DV_7 POINT_5X -52.36 0.652 12.10 DV_8 POINT_1X 0 0.44 10.2 DV_9 POINT_2Y 0 0.375 -9.58 The scope and the influence on the design of design variables can be observed. MSC.ADAMS/View provides all kinds of drawing diagrams as the research report, which include the sensitivity of design variables. As shown in Table 1, the sensitivity of DV_1, DV_2, DV_4, DV_6 is greater. This implies that these four variables influence the optimization results more greatly. 340Four greater sensitivity design points are set, the curve of every design point is changed together by ADAMS/PostProcesser, then are compared and optimized. Through operating the optimization program, four design points are optimized to obtain the optimal results. At last the optimal physical dimension of four-bar linkage is obtained by analyzing and calculating. tan= 0.0035, Q1= 57.59, Q2= 24.90,P1= 46.40, A= 990mm, B= 260mm, C= 1125mm, D= 265mm, E= 478mm, G= 1155mm. By means of ADAMS software, modeling the four-bar linkage according to the calculated size, then analyzing the link point through the trajectory simulation, as shown in Fig. 6. Figure 6. The optimized trajectory curve The optimal result of the four-bar linkage size fully meet the design requirements of hydraulic support by