Yoshihiro Uehara

Development of Small Tool by Micro Fabrication System Applying Elid Grinding Technique

In this study, we attempted to develop a cylindrical grinding machine applying the ELID technique, for use as a microtool. We also carried out a detailed investigation on the performance of the electrode turning method of the ELID system; a microcylindrical shaft and microangular shaft were ground using the cylindrical grinding machine applying ELID technique. Good dimensional accuracy was achieved.

Ultraprecision finishing process integrated ELID grinding and MRF for BK glass

An ultra-precision synergistic finishing process integrated MRF and ELID grinding was proposed for shorten total finishing time and improve finishing quality. Sets of ultra-precision experiments were carried out to grind and finish some optical glass BK materials. ELID grinding, as pre-finishing, was employed to obtain high efficiency and high surface quality; and then, MRF, as the final finishing, was employed to improve further surface roughness and form accuracy. BK13 plane glass was processed by integrated ELID grinding using #4000 wheel and MRF. After ELID grinding, λ/5 P-V was obtained, and then, MRF 30 minutes, the form accuracy was improved to λ/28 P-V. Likewise, curvature BK7 glass lens was also used to test. After ELID grinding using #4000 wheel, form accuracy λ/5 P-V and surface roughness 261 nm rms were obtained; and then, MRF 17 minutes (2 cycles), the form accuracy and the surface micro-roughness were improved to λ/18 P-V and 0.56 nm rms. By applying the ultra-precision synergistic finishing process of ELID-grinding and MRF, the glass materials could be finished to sub-nanometer surface micro roughness and ~20 nm figure accuracy in a short time.

Grinding Characteristics of Cemented Carbide Concave Mirror by Desk-top Type 4-axes Machine “TRIDER-X” with ELID System

In this study, we attempted to develop a desk-top 4-axes machine “TRIDER-X” mounting a ELID system. This paper describes concepts and history of the machine, and detailed investigations on the performance of the machine. A concave mirror was ground using the desk-top 4-axes machine “TRIDER-X” mounting an ELID system. Good form accuracy was achieved.

Ultraprecision fabrication of large stamping die of Wolter mirror for an x-ray telescope by ELID grinding

This paper presents a ultra-precision manufacturing process of large stamping dies with confocal paraboloidal and hyperboloidal surfaces of Wolter mirror for an X-ray telescope. In order to improve the alignment of the two substrates and reduce the degeneration in imaging quality, two compound reflectors were formed from one thin substrate utilizing synthetic ELID grinding and arc-enveloped grinding method. Because the thin foil substrate was obtained by press forming, large stamping dies of foil substrate must be machined with high Fig. error and low roughness. In this ELID arc-enveloped grinding system, cast iron fiber bonded (CIFB) diamond wheels were 3-dimentional controlled to scan the workpiece and generate required surfaces. Through truing grinding wheel and ELID grinding for upper concave and lower convex stamping dies, attainable form accuracy, surface roughness were investigated.

Study on the ELID Grinding Forces of Ceramics and Steels

Grinding forces are very important phenomenon of grinding process. The higher grinding forces show more difficult removing material from workpiece surface. Ceramics is typical brittle material and metal is important ductile materials. These materials have different use due to their physical and mechanical properties. Through the comparative study of ELID (ELectrolytic In-process Dressing) grinding on ceramics and metals, a more thorough knowledge about grinding mechanism may be acquired. But there are few researchers to study on the ELID grinding forces of ceramics and metals on the same experiment. The present experiment was carried out on a surface grinder. Four kinds of material were selected, such as SiC, ZrO2, SKD11 and STAVAX. In grinding process, grinding forces were measured by a three-component forces dynamometer. Fx, Fy, and Fz were respectively in the direction of longitudinal feed, traverse feed and grinding depth of abrasive wheel. On the same conditions, grinding forces of SKD11 and STAVAX were greater than that of SiC and ZrO2.

1402 Development of Desktop type Micro Tool Processing system with ELID Grinding system

Hitoshi OHMORI, RIKEN(The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, 351-0198 Tetsuya NARUSE, RIKEN(The Institute of Physical and Chemical Research) Yoshihiro UEHARA, RIKEN(The Institute of Physical and Chemical Research) Yutaka WATANABE, RIKEN(The Institute of Physical and Chemical Research) Kazutoshi KATAHIRA, RIKEN(The Institute of Physical and Chemical Research) Weimin LIN, RIKEN(The Institute of Physical and Chemical Research) Norihide MITSUISHI, NEXSYS(RIKKEN Venture)

An Experiment of ELID Grinding process for Gradient Index (GRIN) Lens

An Experiment of ELID Grinding Process for Gradient Index (GRIN) Lens RIKEN Yutaka WATANABE, Weimin LIN, Hitoshi OHMORI, Toru SUZUKI, Shin-ya MORITA, Yoshihiro UEHARA, Qing LIU and Akitake MAKINOUCHI ELID (Electrolytic In-Process Dressing) grinding method is possible to achieve ultraprecision smooth surface of hard and brittle materials. To obtain ultra smooth surface required by astronomical observatory, final polish process which required long time after conventional grinding process was necessary. ELID grinding method using an ultraprecision grinding machine tool will be very effective in reducing the time required for finial polishing process. In this paper, a fabrication experiment of Gradient Index (GRIN) lens using this ELID grinding process was studied.