The debris and bubbles accumulation in the inter-electrode area cause the increases in abnormal discharges, which limits the feed depth during micro-hole drilling with electrical discharge machining (EDM). From the direct observation, it is found that debris always adheres to the negative electrode, and the powder-shaped debris gathers to form block-shaped one. On the one hand block-shaped debris makes the inter-electrode gap narrower and hinders the exchange of dielectric, but on the other hand the weak adhesion of block-shaped debris to the electrode leads to the possibility of falling off at any time. In this study, the influence of block-shaped debris and bubbles on the drilling depth was analyzed based on experiments, in which metal debris was artificially put into inter-electrode area.

Electrolytes with bubbles can increase the impedance and reduce electrical conductivity for solution in electrochemical machining (ECM). In this paper, a method of electrochemical machining by using a bipolar pulse power supply and an auxiliary electrode to realize the reduction of stray corrosion is proposed. The auxiliary electrode is used to induce the generation of hydrogen bubbles on the surface of the workpiece and tool in the period of negative pulse, which can restrain the distribution of stray current in the period of positive pulse, thereby reducing stray corrosion and enhancing the machining precision of ECM significantly.

After Hanshin-Awaji Earthquake, improvement works of a highway, bridge, etc. are conducted in all parts of Japan. During an actual operation of drilling a fixing hole, forty works, e.g., cut of a reinforcing member disposed in concrete, usage of a short anchor bolt are conducted, which constitute a social problem. This paper shows a deviated-deep-hole boring for avoiding cut of the disposed reinforcing member by using a MEMS-gyro guided-deep hole-hole drilling system

For the future lunar and planetary explorations, cutting of rock samples is needed for high-precision analysis of compositions. The authors have investigated wire-sawing as a rock machining method which is usable in a vacuum environment. This report introduces a miniaturized device for use as an end-effector mounted on a robot arm. The basic configuration is the same as that of the previous prototype. Two motors are used to apply tension to the saw wire during reciprocating motions.

Electrochemical discharge machining (ECDM) can create fine shapes on insulated materials by generating electric discharges in an electrolyte. An ECD machine can be built in compact size. The authors have developed a lathe-type ECD machine and have obtained machined surfaces with few cracks. In this report, a prototype of a milling machine by ECDM for 3D shape machining wasbuilt, and shape machining wastried by scanning the discharge position. In basic experiments, the removal amount wasincreased with an increase of scanning times of a tool electrode on the workpiece.

Stable accuracy is necessary to achieve automation and unmanned operation of machine tools, and thermal deformation caused by up to 75% of the overall geometric error of the machined workpiece is a critical issue. In particular, the swivel axis is generally subjected to warm-up operation because of its direct influence on machining accuracy. In this study, a wave gear reducer with a high power reduction ratio was mounted on the swivel axis of a 5-axis control machine tool, and displacement measurement and workpiece geometry evaluation were conducted assuming the main machining process during the warm-up operation.

When UV-NIL transfer is repeated in the mold, the mold release agent on the surface is deteriorated and then, resin adhesion or chipping occurs. Using a differential of water contact angle (CA) trend, life-time of release coating layer on mold is possible. Usually, concentration of release agent uses around 0.1 wt%, this value is low, but, lower concentration behavior is unknown. In this study, the properties of low-concentration release were investigated using replica molds with a 100 nm L&S pattern. We also investigated the possibility of increasing the number of transcripts by applying the release treatment again, before the replica mold became unusable.

The problem with UV-NIL is that mold release treatment increases water repellency and air bubbles are generated during NIL. Therefore, it is important to observe the filling behavior of UV-curable resin into UV-NIL mold. Therefore, in this study, in order to improve the durability and sagging, which were problems in the previous study, we created a bridging structure using SU-8, a negative resist, and applied UV-NIL when the transfer pressure was finely changed. We have investigated the filling behavior at time, and report it

In the previous report, we reported that a CNC program with tool center point control generated by block length based on the CNC’s block processing time (Tb) described in the manual enables simultaneous 5-axis machining with higher-speed and higher-precision. In this paper, the block processing time (Tb) is identified by test operation using a more general method than previous studies. It is reported that a CNC program is generated based on the identified block processing time (Tb) and simultaneous 5-axis machining can be performed with higher-speed and higher-precision by machining a workpiece using the generated program.

We propose a method to improve the measurement accuracy of touch-trigger probing on a six-axis robot as a portable in-line 3D measurement device. We show that the estimation accuracy of stylus ball position can be improved by using the model, developed by our research group, which includes the angular positioning error of each rotary axis as an error sources. Artifacts of the pre-calibrated geometrical accuracy were placed at various positions over the entire workspace to investigate the probing measurement accuracy.

Piezoelectric actuators are commonly used for precise positioning and driving due to their excellent properties of high accuracy, quick response, immunity to electromagnetic interference, and large stroke. Currently, there is no academic report that provides a systematic modeling and experimental evaluation of walking-type piezoelectric actuators. Accordingly, a walking-type piezoelectric actuator with triangular mechanisms is developed, dynamics simulated, and performance tested in this study. The dynamic models provide guidance for the design and optimization of walking-type actuators. The experimental results indicate that the actuator realizes a wide operating velocity range, stepping without backward motion, and high-precision positioning.