机械5

摘要 汽车的转向系统在机械式转向系统的基础上随着技术的不断发展完善和人们的要求不断提高，动力式转向系系统因运而生并成为主流转向系统。动力转向系统是在驾驶员靠人力通过各连杆机构作用在转向轮的基础上辅助以发动机的动能通过转向加力装置转化为进行汽车转向的动能来实现转向快速，准确，轻便的一套系统。因此，对于动力转向系统，汽车转向所需的能量只有一小部分由驾驶员提供，而大部分能量由发动机通过转向加力装置提供。而且随着技术的完善，当动力转向系统的转向加力装置失效时，还可以靠转向系统的机械部分由驾驶员独立汽车转向所需的力，从而实现汽车转向。因此，动力式转向系统因其优良的稳定性。安全性和可操作性受到广泛推广[1]。 本文所设计的是中型汽车的转向系统，因此，本文根据中型汽车设计要求，选择整体式循环球式转向器，动力装置选用液压动力装置，并转向控制阀选用常流式滑阀转向阀等。通过查阅资料，参考文献等对动力转向系统的转向器各个零部件，液压动力缸参数及滑阀转向阀参数，转向系统的操纵机构和传动机构进行设计计算和强度校核。最后利用CAXA软件进行转向系统装配图及各零件图的绘制，利用UG三维建模软件对转向系统各个部分进行三维建模和仿真分析。 关键词：循环球式转向系统；液压助力；滑阀；二维装配；三维建模 Abstract The steeri
ng system of automobile is based o
n the mecha
nical steeri
ng system. With the co
nti
nuous developme
nt of tech
nology a
nd the improveme
nt of peopleu
ndefi
neds requireme
nts, the power steeri
ng system has become the mai
nstream steeri
ng system because of its operatio
n. The power steeri
ng system is to realize the rapid steeri
ng o
n the basis of the steeri
ng wheel acti
ng by the driver by ma
npower through the co
n
necti
ng rod mecha
nism. The ki
netic e
nergy of the e
ngi
ne is co
nverted i
nto the ki
netic e
nergy of the automobile steeri
ng by the steeri
ng afterpower device. A
n accurate, portable system. Therefore, for power steeri
ng systems, o
nly a small portio
n of the e
nergy required for vehicle steeri
ng is provided by the driver, while most of the e
nergy is provided by the e
ngi
ne through the steeri
ng afterbur
ner. A
nd with the improveme
nt of tech
nology, whe
n the power steeri
ng systemu
ndefi
neds steeri
ng afterforce device fails, the steeri
ng system ca
n also rely o
n the mecha
nical part of the steeri
ng system by the driveru
ndefi
neds i
ndepe
nde
nt vehicle steeri
ng force, so as to achieve vehicle steeri
ng. Therefore, the power steeri
ng system has excelle
nt stability. Safety a
nd operability are widely promoted. I
n this article, the steeri
ng system of the medium vehicle is desig
ned. Therefore, accordi
ng to the desig
n requireme
nts of the medium vehicle, this paper selects the i
ntegral circulati
ng ball steeri
ng gear, the hydraulic power device for the power pla
nt, a
nd the co
nsta
nt flow slide valve steeri
ng valve for the steeri
ng co
ntrol valve, etc. Through co
nsulti
ng data, refere
nce a
nd so o
n, the desig
n calculatio
n a
nd stre
ngth check of steeri
ng gear parts, hydraulic power cyli
nder parameters a
nd slide valve steeri
ng valve parameters, steeri
ng mecha
nism a
nd tra
nsmissio
n mecha
nism of power steeri
ng system are carried out. Fi
nally, CAXA software is used to draw the assembly drawi
ng a
nd every part drawi
ng of steeri
ng system, a
nd UG software is used to model a
nd simulate each part of steeri
ng system. Keywords: circulati
ng ball steeri
ng system; hydraulic power; slide valve; 2D assembly; 3D modeli
ng 目录 前言1 1汽车主要参数的确定2 1.1汽车主要参数的选择2 2转向系的主要参数3 2.1转向器的效率3 2.2转向系传动比的变化特性4 2.2.1转向系传动比4 2.2.2力传动比与转向系角传动比的关系4 3循环球式转向器设计与计算6 3.1循环球式转向器主要参数的确定6 3.1.1螺杆、钢球、螺母传动副设计6 3.1.2齿条齿扇传动副的设计8 3.2循环球式转向器零件强度计算和校核9 3.2.1转向系计算载荷的确定9 3.2.2钢球与滚道间的接触应力10 3.2.3齿的弯曲应力11 3.2.4转向摇臂轴直径的确定12 4液压动力转向系的设计计算13 4.1液压动力转向机构布置方案的选择13 4.2液压动力缸的设计计算14 4.2.1动力缸内径的计算14 4.2.2活塞行程计算15 4.2.3动力缸缸筒壁厚计算15 4.3转向控制阀的设计计算16 4.3.1预开隙16 4.3.2滑阀总位移量16 4.3.3滑阀直径16 4.3.4滑阀中间位置时油液流速17 4.3.5分配阀得泄漏量17 4.3.6回位弹簧设计计算17 4.4液压油罐容积和液压油泵排量的确定18 5转向传动机构的设计20 6循环球式转向器的三维建模与仿真分析21 6.1转向螺杆的UG三维建模21 6.2齿扇摇臂轴的UG三维建模22 6.3转向螺母的UG三维建模25 6.4转向扭杆的UG三维建模27 6.5转向器壳体的UG三维建模28 6.6循环球式转向器装配30 6.7循环球式转向器的仿真运动分析31 6.8循环球式转向器扭杆的有限元分析33 7技术经济性分析36 8结论38 致谢39 参考文献40