Roughness and precision when machining holes in the rollers of continuous-casting machines by a combined tool

The roughness and geometric precision of deep holes in the rollers of continuous-casting machines produced by a combined tool are investigated. Mathematical models derived from the results permit the calculation of tolerances on the holes in billet and the parameters of the transforming system on the basis of the required shape precision and surface roughness of the holes.     

Efficient inspection planning for coordinate measuring machines

The coordinate measuring machine (CMM) has been recognized as a powerful tool for dimensional and geometric tolerance inspection in the manufacturing industry. The power of the CMM depends heavily on an efficient inspection plan that measures a part in minimal time. This paper proposes CMM inspection planning that can minimize the number of part setups and probe orientations and the inspection feature sequence. In our planning, a greedy heuristic method is adopted to obtain the minimal number of part setups and probe changes. Meanwhile, a continuous Hopfield neural network is developed to solve the inspection feature-sequencing problem. The proposed method was successfully implemented and tested using a machine spindle cover part. The results show that the proposed method can achieve excellent performance compared to the other methods.     

Modal control in the supply drives of metal-cutting machines

Modal control of the transverse supply drive in a numerically controlled lathe is considered. The control method is based on stabilization of the elastic deformation with change in thickness of the cut margin, so as to ensure a constant value within the motor??s armature chain.     

Combined tool for machining deep holes in continuous-casting rollers

The drilling of holes in continuous-casting rollers with cutting and surface plastic deformation by means of a combined tool is described. Such machining ensures high productivity and low cost, with specified quality.     

PLC在铝轧机电控系统改造中的应用

概要介绍了SIEMENS S7-200系列可编程序控制器在铝轧机电控系统改造中的应用。文中对该系列控制器的性能特点及在工业现场的适用性作了较充分的描述。     

Cutting and deformation of deep holes in continuous-casting rollers

A hybrid tool for producing deep holes in the rollers of continuous-casting machines is proposed. The tool ensures high precision and machining quality and also reduces machining costs.     

Applying solid lubricant to the grinding-wheel surface

The application of solid lubricant to the cutting surface of grinding wheels in the course of machining is considered. This technique improves the efficiency and quality of grinding. Two methods of lubricant supply are considered, and an appropriate attachment design is proposed.     

Cooling of a cylindrical crystallizer in a mold continuous-casting machine

The results of structural calculations for the cooling of a cylindrical crystallizer in a continuous casting machine for steel molds are given. The material for crystallizer walls has been replaced. The novelty of this study has been validated with an invention patent.     

Wear prevention in molds used to mold boron filled elastomers

An investigation was conducted to identify surface coatings which would improve the wear characteristics of compression molds used to mold contoured parts from elastomers filled with crystalline boron particles. An analysis was made of the mode of wear present on the surfaces of a production mold, followed by selection and modification of a capillary rheometer as the test device. Test specimens were coated by electroplating, electroless plating, plasma spraying, chemical vapor deposition, sputtering and a fused salt process. Testing was conducted under conditions simulating those encountered in the production molding operation.Techniques used in evaluating the results included optical microscopy, scanning electron microscopy, transmission electron microscopy and surface profilometry. The results are expressed as a ratio of volumetric wear of the tested coating to that of unprotected mold steel.Results indicate that titanium diboride (TiB₂) applied by chemical vapor deposition provides wear resistance superior to plasma sprayed aluminum oxide mixed with titanium dioxide, plasma sprayed chromium oxide, electrodeposited chromium, electroless nickel containing synthetic diamond powder, chemical vapor deposited tungsten carbide (W/W₂C), aluminum oxide and aluminum oxide over chromium carbide. Sputtered titanium diboride was also superior to these coatings and to sputtered titanium carbide and boron carbide.     

基于多支持向量机系统的供应链伙伴关系协同预警框架

为有效地支持供应链合作伙伴关系,保证供应链的协调性,提出了供应链伙伴关系发展程序和基于多支持向量机系统的分布式供应链伙伴关系协同预警框架,并研究了伙伴关系预警的多Agent实现。首先,论述了包括伙伴关系发展程序的供应链伙伴关系管理2维模型;其次,分析了供应链伙伴关系预警问题以及协同预警决策、支持向量机和分布式委员会机器的内在关联;再次,描述了基于多支持向量机系统的伙伴关系协同预警模型及工作原理,进而研究了多Agent的设计,包括多Agent模型、Agent群体目标和个体目标分析、Agent合作步骤论述。最后,通过示例说明了系统的工作流程。     

减少工艺用往复压缩机注油量的试验

根据化工压缩机的实际运行磨损情况，分析了传统压缩机注油量计算公式的缺陷，提出了新的注油量计算公式和经验数据。     

压缩机以脂代油的实验

介绍了压缩机润滑技术中以脂代油、自润滑技术以及抗磨修复技术的发展动向。     

The effect of lubricant inertia in externally pressurized bearings using a viscoelastic lubricant

The inertia effects in an externally pressurized bearing with a viscoelastic lubricant were considered using the methods of averaged inertia and of iteration. The inertia forces reduce the load-bearing capacity at a given flow rate. The effect of the elasticity of the liquid is to increase the pressure and the load-bearing capacity at any point. The effects of the elastic number S, the volume flow rate Q, the ratio σ of the inner radius of the bearing to the outer radius of the bearing and $\text{H =}\text{h}\text{a}$ on the pressure and the loadbearing capacity are presented graphically. The results obtained by the two methods are in good agreement.     

Effect of viscosity variation due to lubricant additives in journal bearings

Micropolar fluid theory, which is a possible non-newtonian model of a suspension of rigid particle additives, is applied to the study of the lubrication of an infinitely long and an infinitesimally short journal bearing. The variation in viscosity along the film thickness is taken into consideration. The prominent feature of the presence of solid particles in the lubricant is an increased effective viscosity which increases the load capacity and decreases the coefficient of friction. Whereas viscosity variation tends to decrease both the load and the coefficient of friction for the non-micropolar case, the combined effect is to increase the load and to decrease the coefficient of friction.     

The influence of lubricant composition on the lubricant breakdown in upsetting between overhanging dies

Upsetting experiments were conducted on aluminum alloy workpieces with a variety of lubricants. Measurements of the width of the unlubricated zone with a mineral oil were in good agreement with Wilson and Carpenter's theory. The addition of surface active materials to the oil did not affect the extent of the unlubricated zone but did reduce the forming load. The breakdown process was also observed with solid lubricant coatings.     

Transmission electron microscopy in lubricant evaluation

A pilot study has been made using transmission electron microscopy to determine how well this technique reveals the microstructure of wear-damaged surface layers in a metal alloy (type 304 stainless steel) and whether the results correlated with lubricants chosen over a wide performance range.     

Boric acid and borax as antiscoring additives to glycerin-based lubricant

Boric acid and borax, which are used as antiscoring additives to an environmentally friendly glycerin-based lubricant, have been studied. It is shown that the adsorption of borax obeys the Langmuir isotherm. The equilibrium constants of the adsorption of the additives and the energy of the adsorption are estimated. It has been found that borax is a more effective antiscoring additive than boric acid. For borax used as the additive, the dependence of the coefficient of friction on the load applied to a friction unit is studied and interpreted.     

An automated laboratory lubricant test to simulate valve train wear

The need for a laboratory tool to screen the antiwear properties of potential additives has become more crucial as engine tests have become more expensive and lubricant requirements have become more stringent. A laboratory test has been developed using the Falex machine to simulate the valve train wear of an automobile engine. The test procedure was 3.5 h long and included two levels of applied load. This laboratory test was found to give reproducible wear and correlated with the Sequence III-C engine wear test. The labor-intensive part of the test was converted to computer control and data acquisition. This conversion improved both test control and productivity.