基于轴类零件的数控加工实践教学创新探讨

就目前我国高校设置的专业来看,数控加工是各个学校的重点专业,学校非常重视对于数控加工人才的培养和教育.在数控加工专业的教学内容中,轴类零件的加工是重要的一部分.伴随着教学改革的不断推进,实践教学逐渐成为轴类零件数控加工教学的重要方法.实践教学法能够弥补传统教学方式的诸多不足,有效提升教学效率和教学质量.文章从实践教学法对于数控加工专业的重要作用入手,分析了轴类零件数控加工实践教学现存的主要问题,并提出了若干落实实践教学的创新方法,希望能够为相关领域的研究人员提供借鉴意义.     

轴类零件的工艺分析与数控仿真加工

轴类零件的加工是机械加工中常见的制造形式,利用数控车床进行轴类零件的批量加工能够很大程度的提高生产效率,同时提高复杂零件的加工质量。通过对轴类零件加工工艺分析过程的介绍,举例说明了指定轴类零件的工艺制定过程,并对该零件进行了数控仿真加工,以保证工艺和编程的正确性。     

数控车床薄壁件的加工工艺分析

随着数控加工技术的日益成熟,越来越多的产品零件采用数控机床来加工,因此如何改进数控加工工艺的问题显得越来越重要。薄壁零件是数控车削中常见加工件,其特殊性要求采用更为合理的加工工艺,文章就薄壁件工件特点、加工工艺进行阐述,确保薄壁件加工件的加工精度与合格率。     

校企合作中齿轮轴加工的工艺革新及其应用

四轴加工中心是多轴机床中的典型代表,随着社会需求的不断增加,企业生产的必然趋势是向先进的制造技术发展。织布机齿轮轴中的孔系和键槽被设计在不同的零件表面,原来是在数控铣床上进行加工,完成零件加工的工序较多,需要四套夹具才能完成,此种加工方法装夹次数较多,定位精度差,零件质量得不到保障,对工人的要求也比较高,针对这种情况,文章就结合四轴数控机床的种类及加工特点对原来的夹具和加工工艺进行改进,使零件加工简单化,从而提高生产率,降低工人的劳动强度。     

平面二次包络环面蜗杆的建模与五轴数控加工技术研究

在获得平面二次包络环面蜗杆三维模型的基础上,运用Cimatron E8.5进行数控编程与仿真加工,为平面二次包络环面蜗杆的五轴数控加工提供了可靠的依据,并使其加工更快捷、简便。     

农机零部件加工中五轴数控加工中心刀具算法应用

为了解决复杂农机零部件的高精度加工难题,在加工工序中引入了五轴数控加工技术,并采用自适应差分算法对加工刀具的轨迹进行了优化,从而有效提高了农机复杂零部件的加工效率和加工精度。在五轴数控加工过程中,需要建立切削模型,但五轴加工过程中的刀具矢量是不断变化的,其计算较为复杂,而本次引入的自适应差分算法可以利用初始化参数数据和曲线拟合方法,确定最佳的走刀轨迹。为了验证算法的可靠性,对刀具轨迹优化效果进行了仿真测试,测试结果表明:采用刀具优化算法后在复杂的零件拐角部位可以得到更佳的走刀轨迹。最后对系统进行了实际的加工实验测试,测试结果表明:采用该数控加工系统可以得到高精度的复杂农机部件的加工效果,为现代农机复杂零部件的加工提供一种新的方向。     

农业机械零件数控加工方法探究

数控加工技术通过利用计算机控制机床进行自动化加工，提高了农业机械零件加工的效率、精度和一致性。本研究通过对比了传统加工和数控加工的优缺点，指出数控加工的高精度、高效率、低误差等优势，针对农业机械零件的特点，分析了数控加工在农业机械零件制造中的应用现状和发展趋势，同时结合实际案例，介绍了数控加工在农业机械零件制造中的具体应用。研究结果旨在为农业机械零件的制造提供参考和借鉴。     

五轴机床若干关键技术

五轴联动机床是数控加工机床中的高端设备,刀具除包含常规直线运动外还包含绕轴线转动,能够以任意角度到达作业空间的任何位置。五轴联动机床除了加工精度非常高之外,还能加工自由曲面等复杂表面,广泛一用于航天、潜艇等高要求的领域。文章对五轴联动机床相关特点等进行相应介绍。     

复杂轴类零件数控车削中细长轴的加工方案

本文针对数控车削中复杂轴类零件细长轴的工艺特点,着重分析了加工细长轴的技术准备,包括刀具几何角度的选择、装夹方案的确定、常见车削方法的介绍。为了解决细长轴类零件在实际加工中存在的刚性低、易变形、精度不容易保证等困难,本文选用了FANUC OI系统CK6136数控车床,对工厂中的典型零件图分析了加工的要点,制定了详细的加工方案。     

五轴机床若干关键技术

五轴联动机床是数控加工机床中的高端设备,刀具除包含常规直线运动外还包含绕轴线转动,能够以任意角度到达作业空间的任何位置。五轴联动机床除了加工精度非常高之外,还能加工自由曲面等复杂表面,广泛一用于航天、潜艇等高要求的领域。文章对五轴联动机床相关特点等进行相应介绍。     

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。