Key Engineering Materials Vols. 375-376

Abstract: In some remote sensing, such as meteorology and oceanography, wide swath scanning must be used. Owing to the limitation of the detector size, especially in infrared spectrum, the optical-mechanical scanning mode is necessary. Scanning efficiency is an important parameter of those scanners. The high scanning efficiency is one of the goals followed after by the designer of remote sensor. Two high efficient scanning systems are developed by authors. Those systems can have some advantages, such as simple and reliable.

Abstract: According to revised Cailikefu’s rolling shear force formula, motion path equation of spatial seven-bar path is built, and mechanical model, with such new structural features as asymmetric and negative offset, is thus successfully established for 2800 mm heavy shear of some Iron&Steel Company. Shear force and bar force of steel plate, before and after adoption of asymmetric and negative offset structure, are analyzed, as well as horizontal force component of mechanism that influences pure rolling shear and back-wall push force that keeps blade clearance. The discovery is that back-wall push force could be kept large enough at rolling start-up (i.e. the time that the maximum rolling shear produces), meanwhile, back-wall push force is the most approximate to side forces with adoption of 60mm~100mm offset. Theoretical results and on-site shear quality both indicate that new structural features such as asymmetric and negative offset plays an important role in ensuring pure rolling shear and keeping blade clearance constant, which provide an effective means to improve quality of steel plate.

Abstract: Currently, most of the diamond turning tools used for precision machining are still manually manufactured, the profile accuracy of the diamond cutting edge depends on the operator’s experience and skill, so that the process need to be automated. Therefore in this research, an automated grinding system has been developed for the diamond turning tools, controlled by a vision system. The profile of the diamond turning tools is captured in real time via CCD camera. The deviation from an ideal circle is calculated and feedback to the controller, the grinding system then removes cutting edge of turning tool selectively to achieve high quality and high productivity.

Abstract: Under optimization deposition parameters, such as the acetone concentration, reactive pressure, the bias power, diamond films was deposited on cemented carbide tools with two-step pretreatment method under different distances between the substrates and hot filaments, and the study on the effect of the distance between the substrates and hot filaments on the crystallographic orientation of diamond films and the characteristics of diamond coated tools were investigated in bias-enhanced HFCVD system in this paper. The cutting performance of diamond coated tools was verified by the experiments of cutting particles reinforced aluminum base composite material with 15 vol.% Si as compared with uncoated ones. The quality of diamond film was analyzed by means of SEM, Raman spectrum, and X-ray diffraction. The optimization deposition processing was obtained. The relative intensity ratio of (111) facet and (220) facet in the film tested by XRD was one third. The cutting performance of diamond coated tool was improved significantly when machining the Si particle reinforced aluminum-based metal matrix composite; its lifetime was as 30 times long as that of uncoated one. The work of this paper was of great practical significance to accelerate the industrialization of diamond films coated WC–Co substrates.

Abstract: The performance and stability of output of electrical discharge machining (EDM) are determined by the output of EDM pulse power supply. In order to resolve disadvantages of conventional pulse power supply, such as undesirable efficiency and low power factor, the prototype design of energy-saving EDM pulse power supply is developed. It is composed of such three stages as a single-phase active power factor correction (PFC) pre-regulator, a full-bridge phase shift zero voltage switching (FB-PS-ZVS) converter based on complex control paralleled of machining current closed-loop and voltage closed-loop at period of spark gap insulation, and a pulse generator based on machining sequence control. The PFC pre-regulator contributes to a great increase to about 0.95 in its power factor. The efficiency of the new system is considerably increased to about 70% due to design of ZVS. The pulse generator contributes to the pulse machining current without a tail. Experiment results demonstrates that the prototype is capable of low electrode wear, high speed, stable machining.

Abstract: A new 5-degrees-of-freedom hybrid kinematic machine(HKM) consisting of a 4-degrees-of-freedom PTS-based parallel kinematics platform with center constraint branch and a serial X axis is developed. The will-be-machined workpiece is mounted on the platform and the spindle movement is driven by the X axis. This new HKM is very different from a conventional serial-type machine. Therefore, a special algorithm that can transfer the cutter location data (CL-data) into machine specific NC commands is essential for the applications of the PTS-X based HKM in real machining of the workpiece with the complicated surface. The workpiece’s location approach on the platform and the orientation transformation of the moving platform relative to the machine coordination system are investigated.

Abstract: During weaving tufting carpet, the improper stop position of tufting machine will result in stop mark, which influences the carpet quality. In this thesis, through theory analysis and experiment research, the influence rule on the stop position of tufting machine to loop yarn tension and to loop-height has been obtained, and a method of eliminating stop mark by stopping machine in high has been put forward. The technology experiment has proved that when it overlaps partly with high position signal, a fixed position of stopping tufting machine in high has been realized by sending out stop instruction and stopping the tufting machine by a brake cylinder, and the best result of eliminating stop mark has achieved.

Abstract: Because of the fierce competition among manufacturers and customers’ diverse needs, it is essential for manufacturers to organize virtual organization to enhance their agilities to the market. However, the job-shop scheduling becomes very complex and very difficult in a temporary virtual organization. To achieve a harmonious collaborative engineering environment, a framework of agent-based collaborative job-shop scheduling is proposed and resource conflicts are discussed, and the theory of rough set and fuzzy appraise are applied to mediate these conflicts.