摘要 本中，我们设计一种新型自行车结构，该自行车可以满足3人同时骑行，也可是左右两边为家长，中间是小孩。为了保证的稳定性，采用四轮结构，维持自行车的稳定性。这种自行车主要是用在旅游景区，摆脱了传统的前后座，可增进一家人的感情以及观赏体验和互动性。而且该自行车更适合一家出来游玩以及情侣等人群。 本自行车的设计在原有的四轮自行车基础上进行改造，以前市面上的自行车主要有平衡性低，造价昂贵等缺点，对他的这些设计问题改善。该自行车的主要结构于传统自行车结构大致相同，只是在原有机构的基础上进行了完善。将原有自行车的优点利用起来，缺点进行完善，增强自行车灵活性。 通过查阅相关文献可知，四轮自行车在国内外发展的现状，接下来，就要根据我们的需求确定一套设计方案，确定各零件尺寸和零件图，对各零件图进行cad制图，其次，我们要确定该自行车的传动结构，确定合适的传动方式。最后，我们通过二维建模软件Autocad以及三维建模软件对自行车的初步模型以及组成自行车各零件进行零件图的绘制。 通过本，我们将大学所学的机械设计基础、工程制图以及一些建模软件进行了融合，将所学知识用到实际之处。 关键词：三人；并排骑行；自行车；车架；链轮 Abstract I
n this paper, we desig
n a
new bicycle structure, the bicycle ca
n meet three people ridi
ng at the same time, but also the left a
nd right sides for pare
nts, the middle is a child. I
n order to e
nsure the stability of the bicycle, the four-wheel structure is adopted to mai
ntai
n the stability of the bicycle. This ki
nd of bicycle is mai
nly used i
n sce
nic spots. It gets rid of the traditio
nal fro
nt a
nd rear seats a
nd ca
n e
nha
nce the family's feeli
ngs, viewi
ng experie
nce a
nd i
nteractio
n. A
nd the bike is more suitable for a family to go out to play a
nd lovers a
nd other people. The desig
n of this bicycle is reformed o
n the basis of the origi
nal four-wheel bicycle. The previous bicycles o
n the market mai
nly have the disadva
ntages of low bala
nce, high cost a
nd so o
n. It is
necessary to improve these desig
n problems. The mai
n structure of the bicycle is almost the same as that of the traditio
nal bicycle, but it is improved o
n the basis of the origi
nal mecha
nism. Make use of the adva
ntages of the origi
nal bicycle, improve the disadva
ntages a
nd e
nha
nce the flexibility of the bicycle. Through co
nsulti
ng the releva
nt literature, we ca
n k
now the curre
nt situatio
n of the developme
nt of four-wheel bicycle at home a
nd abroad. Next, we
need to determi
ne a set of desig
n scheme accordi
ng to our
needs, determi
ne the size a
nd drawi
ng of each part, a
nd carry out CAD drawi
ng for each part drawi
ng. Seco
ndly, we
need to determi
ne the tra
nsmissio
n structure of the bicycle a
nd determi
ne the appropriate tra
nsmissio
n mode. Fi
nally, we use the two-dime
nsio
nal modeli
ng software AutoCAD a
nd the three-dime
nsio
nal modeli
ng software UG to draw the prelimi
nary model of the bicycle a
nd the parts of the bicycle. Through this paper, we will lear
n the U
niversity of mecha
nical desig
n, e
ngi
neeri
ng drawi
ng a
nd some modeli
ng software i
ntegratio
n, the k
nowledge will be used i
n practice. Key words: three people; Ridi
ng side by side; Bicycle; Frame; Sprocket 目录 摘要I Abstract II 第1章绪论1 1.1研究背景及意义1 1.2国内外研究及发展现状2 第2章总体设计8 2.1设计要求8 2.2自行车的设计分析8 2.2.1设计流程分析8 2.2.2自行车的人机工程要求9 2.2.3自行车设计关联人体尺寸分析10 2.2.4自行车设计的技术经济指标11 2.3整体方案选定12 第3章驱动及传动构件设计15 3.1自行车行驶阻力分析15 3.1.1滚动阻力15 3.1.2空气阻力15 3.1.3内部阻力15 3.2结构要素分析16 3.3功率的计算18 3.3.1输出功率的计算18 3.3.2传动效率18 3.4传动比18 3.5前后链轮之间的链传动设计19 3.5.1设计要求19 3.5.2设计过程19 3.6轴的设计20 3.6.1链轮上力的计算20 3.6.2材料21 3.6.3计算轴的最小直径21 3.6.4轴的结构设计21 3.7轴的校核21 3.8键的校核22 3.9轴承的校核22 第4章结构件设计24 4.1车架设计24 4.1.1车架结构设计24 4.1.2车架材料选择26 4.1.3车架焊接工艺制定30 4.1.4车架强度校核30 4.2阿克曼转向机构设计32 4.3前轮叉架设计33 4.4脚蹬设计36 4.5链轮36 4.6前后轮37 4.7车闸38 4.8曲柄38 4.9方向盘39 4.10遮阳棚39 4.11后轴40 4.12整体式靠背座椅40 总结42 参考文献43 致谢44