1、哈工大机械原理大作业之连杆机构运动分析题Harbin Institute of Technology大作业设计说明书课程名称: 设计题目: 院 系: 班 级: 设 计 者: 学 号: 指导教师: 设计时间: 哈尔滨工业大学 连杆机构的分析一连杆机构分析第四题 如图所示是曲柄摇杆机构,各构件长度分别为a,b,c,d,试研究各构件长度的变化对机构急回特性的影响规律。 二机构分析四连杆机构可分为如下两个基本杆组: 级杆组 RRR级杆组 AB为曲柄,做周转运动;CD为摇杆,做摆动运动;BC为连杆;AB,CD均为连架杆,AB为主动件。3建立数学模型为极位夹角,为最大摆角必须满足条件为:1.ab,ac,a
2、d(a为最短杆); 2.Lmin+Lmax其他两杆之和。而且杆长与极位夹角的关系:在AC2B中, 在AC1B中,其中: 最后分以下四种情况讨论:1. 机架长度d变化令a=5,b=30,c=29d由6开始变化至54,步长为1输出杆长a,b,c,d和K。2. 连杆长度b变化令a=5,c=29,d=30b由6开始变化至54,步长为1输出杆长a,b,c,d和K。3. 摇杆长度c变化令a=5,b=29,d=30c由6开始变化至54,步长为1输出杆长a,b,c,d和K。4. 曲柄长度a变化令b=29,c=28,d=30a由5开始变化至27,步长为1输出杆长a,b,c,d和K。四MATLAB编程:1.机架长
3、度变化时 a=5;b=30;c=29;d=6:1:54;m=(d.2-216)./(50.*d);n=(384+d.2)./(70.*d);p=acos(m);q=acos(n);w=p-q;o=(w.*180)/3.14;K=(180+o)./(180-o);fprintf(%.6fn,K);plot(d,K,b)xlabel(?d?);ylabel(?/?);tilte(?); 机架长度变化对K的影响:abcdK5302965.7840375302973.0283615302982.4450445302992.13206953029101.93128953029111.7897455302
4、9121.68376653029131.60097753029141.53421153029151.47900853029161.43243553029171.39247953029181.35770953029191.32707853029201.29980353029211.27528353029221.25305153029231.23273553029241.21403753029251.19671653029261.18057053029271.16543353029281.15116353029291.13763953029301.12475853029311.1124285302
5、9321.10056853029331.08910753029341.07797753029351.06711853029361.05647253029371.04598353029381.03559553029391.02525253029401.01489753029411.00446853029420.99389553029430.98310153029440.97199553029450.96046653029460.94837553029470.93554153029480.92171953029490.90655553029500.88950853029510.8696645302
6、9520.84524253029530.81163953029540.7208102连杆长度变化:a=5;d=30;c=29;b=6:1:54;m=(b-5).2+59)./(60.*(b-5);n=(59+(b+5).2)./(60.*(b+5);p=acos(m);q=acos(n);w=p-q;o=(w.*180)/3.14;K=(180+o)./(180-o);fprintf(%.6fn,K);plot(b,K,b)xlabel(?b?);ylabel(?/?);tilte(?连杆长度变化对k的影响:abcdK5629300.4161465729300.8433215829300.94
7、38175929300.99404051029301.02401051129301.04378351229301.05773751329301.06808751429301.07607151529301.08243351629301.08764751729301.09202951829301.09579551929301.09910152029301.10205952129301.10475552229301.10725552329301.10960852429301.11185752529301.11403652629301.11617352729301.11829252829301.120
8、41652929301.12256553029301.12475853129301.12701253229301.12934753329301.13178153429301.13433453529301.13702753629301.13988453729301.14293253829301.14620053929301.14972654029301.15354954129301.15772354229301.16230754329301.16738054429301.17303954529301.17941254629301.18666854729301.19503854829301.204
9、85454929301.21660855029301.23108955129301.24967355229301.27515455329301.31503255429301.4526493.摇杆长度的变化a=5;d=30;b=29;c=6:1:54;m=(1476-c.2)./(1440);n=(2056-c.2)./(2040);p=acos(m);q=acos(n); w=p-q;o=(w.*180)/3.14;K=(180+o)./(180-o);fprintf(%.6fn,K);plot(c,K,b)xlabel(?c?);ylabel(?/?);tilte(?);摇杆长度的变化对于k
10、的影响:abcdK5296300.9145515297300.9713465298300.9874465299300.99843552910301.00721852911301.01480252912301.02165652913301.02803852914301.03410552915301.03995952916301.04567252917301.05129952918301.05688052919301.06244852920301.06803152921301.07365452922301.07933852923301.08510552924301.09097452925301.0
11、9696552926301.10309852927301.10939452928301.11587552929301.12256552930301.12949152931301.13667952932301.14416352933301.15197852934301.16016652935301.16877352936301.17785352937301.18747152938301.19770152939301.20863452940301.22037752941301.23306552942301.24686052943301.26197252944301.27866552945301.2
12、9729052946301.31831752947301.34239652948301.37046852949301.40395752950301.44517352951301.49823452952301.57169852953301.68928652954302.1331414.曲柄长度的变化:c=28;d=30;b=29;a=5:1:27;m=(116+(29-a).2)./(60*(29-a);n=(116+(29+a).2)./(60*(29+a);p=acos(m);q=acos(n);w=p-q; o=(w.*180)/3.14; K=(180+o)./(180-o); fpri
13、ntf(%.6fn,K);plot(a,K,b)xlabel(?a?);ylabel(?/?);tilte(?);曲柄长度的变化对于k的影响:abcdK52928301.11587562928301.14064472928301.16597082928301.19186292928301.218319102928301.245338112928301.272901122928301.300978132928301.329519142928301.358443152928301.387626162928301.416882172928301.445933182928301.47435819292
14、8301.501521202928301.526436212928301.547540222928301.562263232928301.566177242928301.551091252928301.500164262928301.371121272928300.850199六计算结果分析:1.当机架d增大,其余三杆不变时,K一直减小,减小速度先快后慢。说明机架距离越大,摇杆急回运动越不明显,但机架过长时,K减小不明显,但仍然减小。2.当连杆b增大,其余三杆不变时,K一直增大,增大速度先快后慢再快。说明连杆越长,摇杆急回运动越明显,连杆长度达到一定程度时,K增大不明显,趋于不变,再增长时,急回增大速度加快。3.当摇杆c增大,其余三杆不变时,K一直增大,增大速度先慢后快。说明摇杆越长,摇杆急回运动越明显,摇杆过长时,K增大速度骤增。4.当曲柄a增大,其余三杆不变时,K减小,变化速度是先快后慢。说明摇杆越长,摇杆急回运动速度开始增加,当曲柄长度超过某个值后,急回运动速度骤减。
copyright@ 2008-2022 冰豆网网站版权所有
经营许可证编号:鄂ICP备2022015515号-1