Papers by Author: Toshiharu Shimizu

Abstract: This paper deals with a technique to easily suppress bad odor of water-soluble coolant (working fluid) by using a commercially available ion generator for home use. At the shop floor, water-soluble coolant is in heavy use, where putrid bad odor is apt to be generated from water since over 95% of the coolant component is water, leading to a short life of the coolant. Expecting an effect of suppressing putrid odor of water-soluble coolant, application of ion mixed air using an ion generator for house use was examined. As a result, bubbling with ion mixed air could achieve a drastic suppression of a bad odor generated from putrid water-soluble coolant, compared to a bubbling with air only. In addition, it was confirmed that by discharging ions into a machine emitting a bad odor, the odor level decreases drastically. From these results, a machine having an ion generator built-in can be proposed as an environmentally friendly machine tool.

Abstract: The authors have proposed a new coolant named “micro bubble coolant” in which micro bubbles (20-50µm in diameter) are included. In the previous study, it was clarified that the tool life is improved by applying this new coolant to various machining such as boring, turning and grinding. This paper deals with purification effect of the micro bubble coolant. It has been found from the experiments that bacteria which cause putrefaction of the conventional water soluble coolant are eliminated by generating micro bubbles in the coolant. It has also been clarified that the micro bubble coolant isolates minute machined chips and machine oil from the coolant.

Abstract: In order to apply the floating nozzle method to an angular grinding on the external cylindrical grinding, basic experiments on V-groove grinding with the wheel edge were performed on the surface-grinding machine. The results showed that the floating nozzle method could maintain a good control of the wheel edge wear, leading to improved surface roughness compared with a conventional nozzle.

Abstract: In order to improve the floating nozzle method, a new coolant supply method using a coolant flow guided flexible sheet has been developed. In this paper, basic properties of the coolant supply when the coolant flow guided flexible sheet method is used are investigated. At first, the phenomenon of automatic adherence of the flexible sheet to the wheel surface is observed with a high-speed camera. Next, the effect of the clearance between the sheet and the wheel surface is experimentally investigated. It is found that the thickness of the coolant flow in this clearance is very small as about 0.1mm, and can be controlled to some extent by controlling the coolant flow rate and wheel rotation speed. Furthermore, it is clarified that the influence of the flexible sheet on the electric power consumption of the main spindle motor is small.