DEVELOPMENT OF CALCULATING MODEL APPLICABLE FOR CYLINDER WALL DYNAMIC HEAT TRANSFER

In the calculation of submarine air conditioning load of the early stage, the obtained heat is regarded as cooling load. The confusion of the two words causing the cooling load figured out is abnormally high, and the change of air conditioning cooling load can not be indicated. In accordance with submarine structure and heat transfer characteristics of its inner components, Laplace transformation to heat conduction differential equation of cylinder wall is carried out. The dynamic calculation of submarine conditioning load based on this model is also conducted, and the results of calculation are compared with those of static cooling load calculation. It is concluded that the dynamic cooling load calculation methods can illustrate the change of submarine air conditioning cooling load more accurate than the static one.     

ADAPTIVE CONTROLLER AND ITS APPLICATION IN FORCE SYSTEM OF ASYMMETRIC CYLINDER CONTROLLED BY SYMMETRIC VALVE

Partial pressure, system vibration and asymmetric system dynamic performance exit in asymmetric cylinder controller by symmetric valve hydraulic system. To solve this problem in the force control system, model reference adaptive controller is designed using equilibrium point stability theory and output error equation polynomial. The reference model is selected in such a way that it meets the system dynamic performance. Hardware configuration of asymmetric cylinder controlled by asymmetric valve hydraulic system is replaced by intelligent control algorithm, thus the cost is lowered and easy to application. Simulation results demonstrate that the proposed adaptive control sheme has good adaptive ability and well solves asymmetric dynamic performance problem. The designed adaptive controller is fairly robust to load disturbance and system parameter variation.     

绷丝机上丝装置的自动控制

介绍了绷丝机上丝装置的一种自动控制系统，实践证明它结构简单、准确率高。     

Fatigue failures in low pressure die cast AlSi10Mg cylinder heads

Abstract

Exposed to both high and low cycle fatigue, the modern automotive cylinder head is certainly a demanding application for aluminium alloys. AlSi10Mg cylinder heads were investigated to identify the material issues which impact their performance. Fatigue cracks occurred at or very near the water jacket surface, shown to experience the highest residual stresses after quenching. The majority of these cracks were linked with either extensive porosity, insufficient level of modification or with Fe based intermetallic platelets. The predominance of such features near the water jacket surface is accounted for by the relatively slower solidification near the water jacket surface. Fatigue cracks were almost completely avoided by keeping the density index below 2 to control porosity, by improving the solidification rate to achieve SDAS smaller than 35 micrometres, by limiting the Fe level to a maximum of 0˙12 wt-%, by using a higher quality sand for the manufacture of water jacket cores and, finally, by adopting polymer water quenching practice during heat treatment.     

THE CYLINDER-CIPHER

Questions Thomas Jefferson's attributed invention of the “cylinder cipher,” notes similar devices before and after his time, and introduces a “mystery device” of this nature in the National Cryptologic Museum, Fort George G. Meade MD.     

Three-dimensional finite element analysis of powder compaction process for forming cylinder block of hydraulic pump

Abstract

A three-dimensional finite element analysis of a powder compaction process was undertaken to determine the optimum manufacturing conditions for the complex cylinder block found in the hydraulic pump of an excavator. A porous material model was used to ascertain the material behaviour. The finite element predictions for both the density distribution and compaction load were in good agreement with experimental results.     

抓岩机增压缸的设计

介绍了增压缸的工作原理和主要零部件的设计、标准件的选用及增压缸的特点。     

Development of an Intelligent Pneumatic Cylinder for Distributed Physical Human–Machine Interaction

Pneumatic systems are well known for their advantages and simplicity, and have been applied in various applications. This paper presents the development and experimental evaluation of an intelligent pneumatic cylinder and its control system. The cylinder is designed to have an optical encoder, pressure sensor, valve and a Programmable System on a Chip (PSoC) as the central processing unit. The PSoC will handle I²C communication, input and output data from the analogue to digital converter, counter program and pulse width modulation (PWM) duty cycle. An application tool for a distributed physical human–machine interaction is proposed using an intelligent pneumatic cylinder. The system applied 36 links of the actuator to form an Intelligent Chair Tool (ICT). The control methodology presented contains an inner force loop and an outer position loop implemented using a unified control system driven by PWM to an on/off valve. In this research, four control approaches, i.e., position control, force control, compliance control and viscosity control, were constructed and experimented. The physical properties of various objects were also detected by the intelligent cylinder through the detecting function experiment. Finally, an emulation experiment using mass was carried out and the results clearly show the ability of the intelligent cylinder, and the control approaches towards realization of the future ICT application.