设计基准与工艺基准不同时对轴类零件位置公差的影响

本文针对轴类零件分析了在制订工艺规程时，由于工艺基准与设计基准不同，需要进行位置公差换算的重要性，并结合生产实际，介绍了如何进行位置公差换算，说明位置公差换算对效益有着很大程度的影响。     

最小实体要求及其可逆要求的应用

本文简要介绍了一种新的公差原则，最小实体要求及其可逆要求，并结合镗模的精度设计，分析了它的应用特点，从而说明该公差原则确有提高技术经济效益的使用价值．     

Assessing process capability based on the lower confidence bound of Cpk for asymmetric tolerances

It has been proved that process capability indices provide very efficient measures of the capability of processes from many different perspectives. At the present time, the C_pk index is used more than any other index for measuring process capability. However, most existing research works for capability testing have focused on processes with symmetric tolerances, but not for asymmetric tolerances. A lower confidence bound estimates the minimum process capability, conveying critical information regarding product quality, which is essential to quality assurance. The sample size determination, which provides the sample sizes necessary to achieve a desired lower confidence bound, is directly related to the cost of the data collection plan. This paper provides explicit formulas with efficient algorithms to obtain the lower confidence bounds and sample sizes required for specified precision of the estimation on C_pk for processes with asymmetric tolerances. A Matlab computer program using a binary search method is developed. For the practitioners to use in their in-plant applications, we tabulate lower confidence bounds for some commonly used capability requirement and the sampling accuracy of C_pk for sample sizes determination. A realistic example of forging process is presented to illustrate the applicability of the proposed method.     

Methods to enhance tolerances of Chlorella KR-1 to toxic compounds in flue gas

Possible methods to minimize the toxic effects of SO _x and NO _x on the growth of a highly CO₂ tolerant and fast-growing microalga, Chlorella sp. KR-1, were investigated. Maintaining the pH of the culturing media at an adequate value was quite important to enhancing the tolerances of the microalgae to SO _x and NO _x . Controlling the pH by adding an alkaline solution, using a low flow rate of gas fed to the culture, and using a high concentration of inoculating cells were effective methods to maintaining the proper pH of the culture. Controlling the pH was the most effective method but could be applied only for some specific microalgae.     

Review of Recent Zoom Lens Developments for 35 mm Cinematography at Panavision

A series of high performance zoom lens objectives developed by Panavision over fifteen years, which are very popular in the motion picture (cine) industry, are described. Various aspects of four cine zoom lenses, including; definitions, development, specification, construction, aberrations and tolerances, are discussed.This paper was originally presented at the 2nd International Conference on Optical Design and Fabrication, ODF2000 which was held on November 15-17, 2000 at the International Conference Center, Tokyo, Waseda University, Japan.     

同轴度自动检测系统设计

介绍了同轴度自动检测的原理和实现方法。同轴度自动检测系统以微型计算机为基础,使待测零件圆周中采样点达72处。与手工测量相比提高了精度、减少了测量时间,具有较大的实用性。     

公差原则应用实例分析

公差原则是进行精度设计时处理尺寸公差与形位公差关系的指导原则。本文作者着重阐述3个公差原则的区别,分析典型实例,明确说明三种公差原则的应用场合,并指出合理地选用公差原则对提高机械产品质量、降低生产成本的作用。     

Fuzzy modelling with tolerances

We consider the problem of the resolution of fuzzy equation systems: A certain number of fuzzy inputs and outputs is given. How can we determine a fuzzy relation which describes the behaviour of the object under consideration? When attributing this problem to fuzzy equations in the classical sense it may happen that a solution does not exist. Therefore we introduce fuzzy tolerances as an extension of the solvability conception. For this problem we get the whole solution set by means of posets. Moreover, we consider the inverse problem: How to determine tolerances to get consistency (i.e. at least one solution) for the arising equation system.     

尺寸公差标注的计算机辅助设计

本文介绍尺寸公差标注的CAD软件.该软件是对Auto CAD系统的二次开发.扩充了Auto CAD的性能.     

滑动轴承的容许差设计

滑动轴承的间隙对滑动轴承性能有很大的影响。严格的间隙要靠合适的配合种类、配合精度来保证。建立各种动配合的公差计算数学模型,用计算机算出S_(min),S_(max),等轴承参数,可以辅助滑动轴承的容许差设计。滑动轴承的间隙必须保证紧公差以保证轴承的良好的摩擦学性能,提高机械装备的可靠性。