巧换机车零件

1.巧换柱塞弹簧 发动机在工作中柱塞弹簧折断的现象时有发生。但Ⅰ、Ⅱ、Ⅲ号喷油泵在机车上更换柱塞弹簧又很困难。现介绍一种在没有试验台的情况下,巧换柱塞弹簧的简单方法:(1)取下油泵的上泵体,注意柱塞副不能装乱;(2)换上新的柱塞弹簧,并把柱塞放在清洁的油中     

提高油泵柱塞弹簧的使用寿命

长期以来柱塞弹簧容易折断一直是维修人员和机手比较头痛的问题 ,下面就柱塞弹簧为什么容易断以及如何提高柱塞弹簧的使用寿命进行分析和探讨。1、柱塞弹簧是油泵的重要组成部分。其强度、柔韧性稍不符合要求 ,就极易折断 ,失去正常的技术状态 ,造成发动机在行驶过程中突然马力下降 ,工作不稳 ,冒黑烟 ,怠速时发动机转速不平稳 ,上坡没有力气 ,容易失火等 ,所以柱塞弹簧本身质量差 ,材质不稳定 ,强度太强或太弱 ,弹簧上下座歪斜 ,就很容易使弹簧折断 ,故换用新弹簧时要挑每根高度一致的弹簧 ,然后再用微火烧一烧 ,使弹簧回火。2、柴油是否清…     

巧换拖拉机零件

１巧换柱塞弹簧发动机在工作中柱塞弹簧折断的现象时有发生。但Ⅰ、Ⅱ、Ⅲ号油泵在拖拉机上更换柱塞弹簧又很困难。现介绍一种在没有试验台的情况下，巧换柱塞弹簧的简单方法。１１取下油泵的上泵体，注意柱塞副不能错乱。１２换上新的柱塞弹簧，并把柱塞放在清洁的油...     

巧换机车零件

1.巧换柱塞弹簧 现介绍一种在没有试验台的情况下,巧换柱塞弹簧的简单方法:(1)取下油泵的上泵体,注意柱塞副不能装乱;(2)换上新的柱塞弹簧,并把柱塞放在清洁的油中冲洗干净,插到柱塞套内;(3)用棉线将调节臂吊起,并     

气门外弹簧的模糊可靠性优化设计

根据模糊数学,可靠性设计和优化设计原理,建立了气门外弹簧的模糊可靠性优化设计模型,并编制了计算机程序,可完成弹簧的模糊可靠性优化设计和实用模糊可靠度,刚度误差和最大变形等参量的校核计算。对弹簧优化设计中的核心问题－优化算法的选取和连续变量最优化计算解的离散化处理进行了全面的讨论,对优化计算过程中的局部最优解和全局最优解进行了分析。     

故障两则

一、一台泰山—25型拖拉机,更换柱塞弹簧后,喷油泵上体被顶坏。经检查,原来是弹簧不符合要求(弹簧钢丝直径较大),致使弹簧压缩到最小极限时,油泵凸轮仍能使柱塞弹簧上移,导致喷油泵上体损坏,换用标准柱塞弹簧后,故障即除。 二、一台大修后的195型柴油机,工作一段时间后自动     

弹簧件使用与维护不可忽视

虽然弹簧结构简单 ,但作用很大 ,机动车上不少地方少不了它。但目前 ,很多机手没有注意到弹簧的使用寿命 ,只要弹簧不断 ,就继续使用 ,从而导致了机车技术状态恶化 ,降低机器的动力性。因此 ,在使用机车时 ,要重视对部分弹簧的正确使用和维护。1 高压油泵柱塞弹簧当高压油泵柱塞弹簧使用时间较长后 ,由于受周期性高频交变力的作用 ,就会发生磨损和塑性变形 ,从而使其自由长度缩短 ,弹力减弱 ,导致柱塞的回位速度减慢。这样当发动机高速运转时 ,柱塞的往复运动就不能与油泵凸轮的高速回转运动保持协调关系 ,从而使柱塞的升程相应减少 ,从而供…     

东方红—802拖拉机喷油泵维修经验两例

1.柱塞弹簧折断 据用户反映,该泵第三缸弹簧已经断了三次,且每次换上新的弹簧后,使用不到一星期就又断了。该泵是洛拖生产的改进型Ⅱ泵,其挺柱体导向部分与柱塞弹簧下座的结构比较特殊。     

修理三则

一、Ⅱ号喷油泵柱塞弹簧的代用 Ⅱ号喷油泵柱塞弹簧,在使用中断裂。如果一时缺少配件,可用1105型柴油机的调速器弹簧代替,因为这两种弹簧的参数相近。我队有3台拖拉机换用这种弹簧,经多年使用效果良好。     

燃油系中4个不得随意改变

１．柱塞弹簧的高度不得随意改变 喷油泵在使用中出现柱塞弹簧折断是常见的故障。在我们的工作中发现有的机手在柱塞弹簧折断后，所更换的弹簧与原弹簧的圈数不同、高低不等。按要求在同一台喷油泵上，应选择圈数和高度相同的弹簧。弹簧圈数过多或过高，将会造成凸轮轴受力过大，加剧供油凸轮和挺柱的磨损。弹簧圈数过少或过低，在柱塞上行供油时，弹簧压缩余隙过大，柱塞回位太慢，甚至回位不到家就又开始供油，使供油量减少。更换的柱塞弹簧出现高低不等、弹性不一致时，还会导致供油量不均，直接影响柴油机的经济性和动力性。 二．高压油…     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。