Applied Mechanics and Materials Vols. 37-38

Abstract: According to the development of Numerical Control (NC) machine tool’s manufacture, the way to build a platform of digitized design and manufacture system for NC machine tool was proposed, in which the various and relatively simplex digitized technologies were conformed as well as closely combined with the network and information technologies. From that, the real-time and parallel simulation in the whole process of NC machine tool’s design and manufacture would be achieved. Along with the all-sided expanding of digitized technology in the design field of NC machine tool, the corporations’ colligation which includes design, manufacture and management would be greatly upgraded and the development of entire manufacture will be expedited. And the mechanical equipments’ design and manufacture will be promoted at a larger-scale.

Abstract: Deep study on Inside Right-angle Step (IRS) forming process was conducted to improve the precision of its (IRS) forming. According to its actual forming process, the zone, or the undeformed zone, was looked as semi-spiral declined cone and excluded the contact zone. A new algorithm was developed for calculating the size of the undeformed zone. More simple mathematical models and expressions weredeveloped for solving the shaping curve. The model was verified in terms of its simplicity and correctness based on the numerical simulation.

Abstract: Combined scale of the phase characteristics, let the hang iron machine as an example, this paper introduces the type of steam and steam appliances unit, analyses the formation mechanism of scale in steam equipment from the perspective of the chemical and physical, and studies the influence between structure of steam plant and the formation of boiler scale, loss, and sewage. A reasonable design solution is proposed through the analysis of various factors.

Abstract: A series of experiment were performed to test the cleaning ability of different organic emulsion for Si₃N₄ ceramic grinding. The experiment results showed that the grinding fluid made by short chain organic substance and alkane will induces the jam of grinding wheels. At the same time, polar organic substance with long carbon chain can suppress wheel loading phenomenon. The main reason of the jam by alkane is the nonpolar oil film surface possesses the strong attraction to abrasive dust of Si₃N₄, which will lead to jam in the grinding process. The polar oil film relieves the aggregation of abrasive dust in the grinding area to some extant, which is beneficial to decrease jam. By analyzing the cleaning property by some types of polar organic substances, the paper discusses the relationships of molecular structure characters to their cleaning ability.

Abstract: This paper presents a study on the electrothermal explosion of metallic powders produced by a pulsed high voltage generator, which is a fast-discharge capacitive storage device. The character of instantaneous current, voltage were measured and studied. The energy-utilization ratio was calculated and analyzed. It is shown that the maximum current density and current rise rate obtained during electrothermal explosion of Cu powder were of the order of 10⁸A/cm² and 10¹³A/s, respectively. The total energy deposited on exploding was 38.57%~65.90% of the total electrically stored energy, and increased with the charging voltage and powder masses exploding increasing. Meanwhile, the electrical energy applied to the powder was estimated to be about 1.5~2 times the energy theoretically required to vaporization of the powder and metallic exploding. And the energy input in exploding supplied by circuit increased with the charging voltage and the metallic powder conductor height increasing.

Abstract: In this paper, the existing research and key technologies of 4-DOF parallel robot are reviewed, i.e., mechanism, kinematics, singularity, workspace, dexterity, dynamics and control. Most of them are focused on mechanism and kinematics. The study in dynamics and control is relatively rare and not mature in practice, especially in how to optimize the control strategies to improve its performance. Finally, the research trend and unsolved problem of 4-DOF parallel robot is described.

Abstract: Based on the unique merit of double-helix single-screw pump, its working principle is analyzed and its rolling bush and screw profile are designed in this paper. The 3D modeling and virtual assembly of double-helix Screw Pump are established based on Pro/E. The results showed that the multiphase pump could assembly with the design without interference. It provided the reference for optimal design and experimental prototype manufacturing.

Abstract: Ultrasonic machining (USM) is a mechanical material removal process used to erode holes and cavities in hard or brittle work pieces by using shaped tools, high-frequency mechanical motion, and an abrasive slurry. There are many physical signals in the ultrasonic machining which are related with the material removal rate, machining accuracy, and surface finish. So how to measure and control these signals with accuracy is very important. The aim of the paper is to summarize different kinds of physical signals and the methods of measuring and controlling them in ultrasonic machining.

Abstract: The development of hardware and software of the test system for crankshaft balancing machine based on industrial PC was discussed and the method and process of calibration of unbalance were presented. It shows that the dimension and direction of the unbalance can be measured in practice.

Abstract: In order to test the reliability of automobile hydraulic, the vibration reliability test needs to be done. The fixture, which is used to clamp and fix the hydraulic system, is one of the most important components of the test. So the dynamic performance of the fixture has great influence on the vibration test. According to the figure and setting localization of electronics, the three-dimensional model of fixture was constituted. The modal frequency and vibration modal were calculated using FEM. By the result of analysis, the structure of the fixture was mended to meet the test requirement.