机械原理课程设计.docx

机械原理课程设计说明书
——自卸车倾卸机构创新设计

学 院： 机械工程学院
班 级：
组 员：

指导教师：

一月四日

摘 要
我们组选择自卸车倾卸机构的创新设计作为课程设计的题目.为了完毕课程设计,我们一方面查找了关于自卸车倾卸机构的发展史,了解了自卸车的发展历程与现状.然后我们查找了关于自卸的国内外专利,并分析其机构,画出机构简图.知道了自卸车有各种不同的机构,并了解了现在常用的自卸机构以及自卸机构未来的发展趋势.
为了创新设计,我们现场对常见自卸车的自卸机构拍照.分析机构,并进行了运动链的一般化,数综合,特定化和具体化等一系列过程.最后得出27个也许的机构简图.在进行比较时,我们选择了一个不是当前流行类型的机构简图作为自己的创新设计.按对自卸车较为常见的规定:车斗最大倾角,机构纵深,液压缸伸缩距离,结构合理等,我们设计了创新机构的尺寸.在用inventor对其进行运动仿真后,发现结构运动平稳.然后我们又用matlab对机构进行建模,仿真.得出机构的角速度,角加速度等图形.发现机构角速度变化幅度不大,符合仿真动画,满足实际规定,因此,我们拟定了我们的创新设计符合规定并将其作为最终的课程设计的方案.
Abstract
Our group chooses dump truck dumping mechanism innovation design as curriculum design questions. In order to complete the course design, we first look for the dump truck dumping mechanism about the history of the dump truck, understand the development course and present situation. Then we find about dumping domestic and foreign patents, and analyzes the mechanism, draw the mechanism diagram. Know the dump truck, there are all kinds of different organizations, and to understand the present commonly used self-discharging institutions and self-discharging mechanism the future trend of development.
In order to creative design, our site to the common dumper's self-discharging mechanism photos. Body analysis and the kinematic chain of generalization, several comprehensive, specialization and shape and a series of process that. At last, we give 27 possible mechanism diagrams. In comparison, we chose a not current popular type of mechanism diagram as their innovative design. According to the requirements of the more common to dump truck, car bucket maximum Angle of inclination, the agency depth, hydraulic cylinder expansion distance, reasonable structure and so on, we design the innovation organization in the size of the inventor. The motion simulation, found that the smooth movement structure. Then we　use MATLAB　to mechanism modeling, simulation. Draw mechanism of angular velocity, angular acceleration and angular velocity change graphics. Find institutions range is not too much, in line with the simulation animation, meet the practical requirements, therefore, we determine our innovative design meet the requirements as their final course design scheme.
目 录
一、 题目简介 1
1. 题目描述 1
2. 原始数据和设计规格 2
二、 现有机构分析 2
1. 文献综述 2
2. Literature Review 4
3. 现有机构分析 6
三、 机构创新（Creative Mechanism Design Methodology） 17
1. Brief Diagram of the Prototype: 17
2. Generalization: 17
3. Number synthesis 17
4. Specialization 17
5. Particularization: 24
四、 尺寸设计 26
1. 尺寸设计 26
2. 设计图 27
五、 机构分析与仿真 28
1. Inventor仿真图像 28
2. Matlab仿真过程 28
六、 总 结 33
七、 Reference 34
八、 附 录 35
1. MATLAB程序代码： 35

一、 题目简介
1. 题目描述
自卸车是一种通过车自身的倾卸机构，可以将车斗中货品倾卸出去的一种车。自卸车倾卸机构的创新设计就是对现有的自卸机构进行创新再设计，使其满足自卸的使用规定。平稳倾卸货品。如下图中，液压缸作为动力原件，液压缸的伸缩，通过六杆机构的转换，使车斗倾斜，达成倾卸货品的目的。
自卸车图片Pictures of a Dump Truck

图1
自卸车机构简图Brief Diagram of the Dump Truck

图2
DOF=3n-2Pl-Ph=3x5-2x7=1
2. 原始数据和设计规格
（1） 选小车型设计，车斗长5米左右.
（2） 为使货品倾卸完全，车斗最大倾角应在45~70度，可以选择60度.
（3） 单级液压缸，最大伸缩长度在0.5~0.8m.
（4） 机构纵深约为0.5m.
二、 现有机构分析
1. 文献综述
最早的自卸车是以马拉的形式的二轮装卸车，货品重心在二轮车的轮轴上，当装载货品时，只需要放到轴上就可以了，货品前方用绳子勾住固定；卸载时倾卸车即可。这种二轮车曾用在开放矿场，用马匹拉着在铁轨上行走。
1900之后，一种四轮的马拉式平板自卸车诞生，它带有一个矩形货品箱，通过车前的绳子来实现倾卸。
初期的马拉式自卸车
最早出现的自卸车车身是根据装卸重心位置的原则设计的，这种车最早出现在192023，那时曼式重力倾卸机构在英国出现。
液压倾斜机构自卸车
液压力学运用在较早的马拉式自卸车上，根据记载表白，一种最早的液压倾斜机构运用在罗伯逊汽车上，它带有一个液压起重机，可以从汽车的发动机或者一个独立的蒸汽机里获得动力。Alley & McLellan of Glasgow在192023发明了初期的依靠蒸汽驱动的液压倾斜机构。
履带式拖车
在19世纪2023代中期，履带式拖车牵引轮式自卸车迅速流行。有时拖车可以拉两到五个附加拖车，很多公司开始发展可附加式拖车。最早的拖车是运营在轨道上的，但是当速度越来越受到限制时，开始使用轮胎来提高速度。这种轨道式拖车的发明者有Euclid, James Hagy, LaPlant-Choate, Rex-Watson, and Streich 和Western。
Euclid自卸车
Euclid是自卸车发展的先驱者。George Armington的儿子George Armington Jr.设计和制作了两种对世界自卸车有重大意义的发明，涉及现代重型越野卡车和轮式拖车置底倾斜车。
1934年，这个公司发明了10/11吨级自卸车，名为"Trak Truk."。它是第一个用来重型越野服务的后卸式自卸车，后来又发明了15吨级的自卸车，得到很大的改善。
19世纪50年代的自卸车
到了19世纪40年代，自卸车的科技发展达成了一个新的高度，截至19世纪50年代，美国已经发明了置底式自卸车，1951年，Euclid公司制作出世界上最大的自卸车1LLD。1954年Komatsu公司制作出时速为42千米净载重为13.60吨的轮式自卸车。1958年，自卸车市场上最大马力的单独发动机为AP40，可达600马力。
Ralph H. Kress和Haulpak
Ralph H. Kress以他发明的前置式自卸车，重型越野自卸车在矿场的运用而闻名于整个自卸车的世界。
1955年，作为WABCO (现在是 Komatsu)的创始者，他致力于可缩短轴距拥有深、斜、平特点的车身的设计，它就是Haulpak，被视为量子发展设计。
最早的Haulpak于1957年在市场上出现，它可以有32吨级的净载量，后来发展为75吨级。这些最早的自卸车吨级范围为25到32吨级，由于太小而广泛应用于矿场。Haulpak最终由于在尺寸上的发展，成为表面矿场工业的选择。
专利综述
目前，自卸车从单纯的5吨自卸车逐渐向更高吨位的方向发展，举升机构也从简朴的单级缸中置直顶式、多级缸中置直顶式向单级缸连杆组合式、多级缸前置直顶式的方向发展。液压倾斜机构是自卸车的核心，是判别自卸车优劣的首要指标。不同的举升机构，有不同的车型定位和市场定位。
从美国专利局所查找的专利中我们可以看到大部分自卸车为单杠连杆组合式，例如US2849255, US3172703, US3620458 or so. US4036528。US6382731运用多级缸中置直顶式。
下面是各个形式举升机构的优缺陷。
单级缸中置直顶式举升机构——是最早出现的举升机构，机构简朴，紧凑，受力直观，并且成本低廉，在载重量为5吨或者5吨以下的自卸车中普遍采用。US4036528运用此机构。
多级缸中置直顶式举升机构——为了改善单级缸直顶式举升机构的弱点，多级缸中置直顶式举升机构应运而生。它极大改善了油缸和副车架的使用环境，使油缸和副车架的手里很小，使整个液压系统的使用寿命大大延长。并且，由于多级缸是套筒式的结构，内泻量小。缺陷是在布置上比较困难，液压系统过于复杂。在国内一般不被使用。专利US4056283。
单级缸连杆组合式举升机构——有升平稳，超载能力强，系统液压性能好等特点，因而被各大汽车改装厂采用，通过对四杆机构的优化设计，可以设计出多种连杆组合式机构。马进里式和油缸浮动式采用较多，其他由于具有缸径大，油缸行程短等因素采用过的较少。专利US4168861。
多级缸前置直顶式举升机构——重要由一支多节缸组成，行程大5~6米，可以把重心将到最低，极大的改善了车辆的稳定性。由于该机构受力最简朴，最省力，因此，采用多级缸前置直顶式举升机构的自卸车是此后重型自卸车的发展方向。但是有两点缺陷，一是成本最昂贵，二是它的油缸行程过，三是控制系统过于灵敏。目前国内生产这种机构的不多。专利US5033794, US6382731。
国内自卸车发展前景
目前国内自卸车发展重要受到两个问题的影响：大重力重心和重型载重。国内大部分自卸车运用了单级缸连杆组合式举升机构，在发展趋势为多级缸前置直顶式举升机构的前提下，尽管国内运用很少，但是我们相信，在不久的将来，它一定会迅速发展起来。

2. Literature Review
The very first version of a dump truck used to haul and dump material was nothing more than a simple dump body style cart drawn by horses. It would have consisted of a two-wheeled cart hinged

图3
to the axle with the center of gravity, when loaded, just behind the axle. The loaded front body was hooked, and when unlatched, would dump. These carts were used in open mines and pulled by horses along a railway track.
After 1900, a four-wheeled horse-drawn flatbed wagon with a rectangular body lifted with a hand hoist in the front was employed.
Early Truck Mounted Dump Bodies
The earliest versions of truck mounted dump bodies relied on the principle of gravity for dumping. Some of the first trucks with dump bodies designed on this principle appeared as early as 1904 when the Mann gravity dump was built in England.
Hydraulic Dump Bodies
Hydraulics was being incorporated into truck mounted dump bodies relatively early on. Records show that one of the first hydraulic dump bodies was the Robertson Steam Wagon with a hydraulic hoist that received power from the truck’s engine or an independent steam engine. Alley & McLellan of Glasgow developed another early hydraulic dump body in 1907 that was power-driven by steam.
Crawler Tractor-trailers
In the middle of the 1920s, crawler tractors pulling heavy dump trailers mounted on wheels or tracks were becoming increasingly popular. Sometimes crawlers would pull two to five attached trailers. Companies began developing wagons specifically designed for attachment to crawler tractors. The first versions were mounted on tracks; however, when speed restrictions posed a problem, the wagons were mounted on wheels to improve speed. Manufacturers of such trailers and haulers included Euclid, James Hagy, LaPlant-Choate, Rex-Watson, and Streich and Western.
Euclid Dump Trucks
Euclid was a pioneer in the development of dump trucks. George Armington Jr., son of founder George Armington, was a hydraulics designer and made two significant contributions to the world of dump trucks. These included the modern heavy duty off-highway truck and the wheel tractor bottom dump wagon.
In 1934 the company introduced its 10/11-ton dump truck called the "Trak Truk." It was the first rear-dump truck that was designed for heavy-duty off road service. This was followed up in 1936 with the company’s 15-ton Model IFD truck that featured a diesel engine, modern drive line, planetary final drives, leaf-spring suspension, and pneumatic tires. The truck replaced heavy, gasoline powered chain drive Mack trucks that had previously been used for standard work in construction and mining operations.
Dump Trucks in the 1950s
By the 1940s the technological development of dump trucks had reached its peak. In the U.S., bottom dump trucks were already dominating earthmoving sites by the 1950s. The decade continued to mark a proliferation in the manufacturing of dump trucks. In 1951, for example, Euclid produced the world’s largest dump truck when it manufactured the 1LLD. In 1954 Komatsu built the first dump truck on wheels that traveled at 26 miles (42 km) per hour and had a 13.60-ton payload. In 1958, the 600 horsepower AP40 Auto car was the largest single engine dump truck on the market.
Ralph H. Kress and the Haulpak
Ralph Kress is perhaps best known in the dump truck world for pioneering and bringing dump truck technology to the forefront, in particular, heavy-duty, off-road dump trucks used in mining.
In 1955, as a consultant for WABCO (now Komatsu), he was instrumental in configuring a dump truck that incorporated a short wheelbase and had a high angle of turn with a deep, sloped, flat body known as a Haulpak and was viewed as the “quantum advance in design” with its hydro-pneumatic “Hydrair” struts.
The first versions of the Haulpak were made available to the market in 1957 featuring 25- to 32-ton payload capacities and were eventually marketed and used as tractors to pull supplementary 75-ton trailers. These earlier versions, ranging from 25- to 32-ton range capacity, were too small initially to be used in open pit mines but gained acceptance from contractors. Eventually Haulpak grew in size and became the dump truck of choice in the surface mining industry. The Haulpak would exist as the standard to which other off-highway dump trucks would come to be designed.

3. 现有机构分析
（1）专利综述Patent Review
The dump truck, as one the largest special vehicles, is developing from the 5t dump truck to more tons. The core of a dump truck is the lifting mechanism, which develops from the single cylinder centrally-mounted straight top type and the multistage cylinder centrally-mounted straight top type to the single cylinder connecting rod combined type and the multistage cylinder lead straight top type.
From the patents among the searching results from the US patent and trade mark office, we can see that most of the trucks are designed with the single cylinder connecting rod combined type such as US2849255, US3172703, US3620458 or so. US4036528 uses the single cylinder centrally-mounted straight top type. US6382731 uses the multistage cylinder lead straight top type.
Here are some advantages and disadvantages of the four type of the dumping mechanism:
The single cylinder centrally-mounted straight top type—— it is the pioneer of the lifting mechanism of the dump truck. Its structure is very simple and tight and its cost is low, but its load is very small so that it is used as the trucks below 5t. It is widely used as light-weight trucks, for example Dongfeng 3092F uses this lifting mechanism. See Patent: US4036528.

图4
The multistage cylinder centrally-mounted straight top type—— it improves the disadvantages of the single cylinder centrally-mounted straight top type. It improves the condition of the cylinder and the frame to extend their lifetime and reduces the inside discharge of the cylinder. But the framework design is difficult. It makes the hydraulic system complex and costs a lot, so it is not commonly used. See Patent: US4056283.

图5
The single cylinder connecting rod combined type—— it has the stable lifting ability, strong overloading ability and good hydraulic characteristics. It can be changed into different style through changing the four-bar linkage. Mallory type is one of the types and widely used in China because of the characteristics of small cylinder diameters and long cylinder routes. But some types is not widely used because of big cylinder diameters and short cylinder routes. See Patent: US4168861.

图6
The multistage cylinder lead straight top type—— is made up of one multistage cylinder whose route can be 5 to 6 meters. It is the simplest lifting mechanism and largely improves the stability of the truck. It is the development direction of the dump truck. But its cost is the most expensive, which restricts its development in China. See Patent: US5033794, US6382731.

图7
The future of Dump Trucks in China
Most of the dump trucks in China use the single cylinder connecting rod combined type, from the single cylinder centrally-mounted straight top type and the multistage cylinder centrally-mounted straight top type. The trend of development is the multistage cylinder lead straight top type and the type will be developed, but we can’t see a lot in China. We believe in the distant future it can quickly be developed and used in our country.
The front multi-level cylinder lifting mechanism is the leading direction of dump truck manufacturing. For now, the dump trucks in our country are bothered by two main problems: high gravity center and heavy dead weight. To overcome these two obstacles, the younger generation and the technical engineers need to work hard to improve the competing ability of our production.
All in all, the key point is to improve the quality of our products.

（2）专利列表Patent List
Patent No.
App Time
Patent Name
Inventor
Drawing Figures
Brief Diagram
The Types
US2094521
1935.10.11
LIFTING MECHANISM FOR DUMP BODIES
F. BISZANTZ et al

Invention Patent;
Eight-bar Linkage
US2449202
1946.11.8
HYDRAULIC ACTUATING MECHANISM FOR DUMP TRUCKS
Claims. (Cl et al

Invention Patent;
Four-bar Linkage
US2593776
1950.3.21
DUMP BODY TILTING MECHANISM
Charles E. Margala et al

Invention Patent;
Six-bar Linkage
US2849255
1955.8.16
HOIST MECHANISM FOR DUMP TRUCKS
Gerald J. Pasker et al

Invention Patent;
Six-bar Linkage
US3172703
1963.6.14
DUMP MECHANISM FOR TRUCKS
Joan A. Byer

Invention Patent;
Six-bar Linkage
US3512836
1968.10.9
LATERAL STABILIZING MEANS FOR A SEMI-TRAILER DUMP BODY
Anthony Policfa et al

Invention Patent;
Eight-bar Linkage
US3620458
1970.4.21
ALBERT RATH XY
Steel Products Ltd. Preston et al

Utility Model Patent;
Six-bar Linkage
US4036528
1975.10.14
Truck with tiltable body
Heinrich Langendorf

Invention Patent;
Four-bar Linkage
US4049316
1976.1.29
Lifting mechanisms for truck bodies
Marino Paneda Ordonez

Invention Patent;
Six-bar Linkage
US4052105
1976.4.9
Truck hoist
Walter Moe

Invention Patent;
Six-bar Linkage
US4066296
1976.12.28
Truck bed tilting mechanism
Louis M. Ray, Jr. et al

Invention Patent;
Six-bar Linkage
US4056283
1977.1.25
Truck construction
Robert Marvin Pow

Utility Model Patent;
Six-bar Linkage
US4168861
1978.2.6
Dump-hoist conversion system
Ollie J. Carroll

Utility Model Patent;
Six-bar Linkage
US4302050
1979.10.17
Truck hoist
Eldon D. Jones

Utility Model Patent;
Six-bar Linkage
US4382632
1982.6.