Naomichi Furushiro

Highly responsive and stable flow control valve using a PZT transducer

Pneumatic actuators are widely used because they are lightweight and inexpensive. However, highly controllable devices for pneumatic actuators generally have large volume and low response and are heavy. We have developed the flow control valves that have highly controllable using PZT elements. These control valves can downsize the control valve with high response. Using a PZT transducer, we introduced a new mechanism of the control valve for stable continuous flow rate. In this report, we proposed a new mechanism to realize stable continuous flow with a PZT transducer. We designed prototype using a bolt-clamped Langevin transducer (BLT) and show the characteristics of the valve.

Small size pneumatic valve for smooth flow control using PZT vibrator

Pneumatic actuators have the potential to be downsized because they have simple structure. However, many control devices that can control pneumatic actuators continuously have large volume and weight. We have designed a flow-control valve driven by PZT vibrator. This control valve has small volume and low weight, and it can control air flow smoothly. This valve is suited to control small pneumatic actuators. The flow control valve that we propose uses resonance vibration with a PZT vibrator. The valve consists of an orifice plate, a PZT vibrator and iron particles that work as the poppet. From experimental flow quantity evaluation, this control valve controls air flow smoothly with low hysteresis at a large flow rate. In addition, this flow control valve achieves a maximum flow rate of 65 L/min under air pressure of 0.70 MPa. The results show that the valve has high controllability and can control a relatively large flow rate compared to its weight and size.

Three-Dimensional Microscopic Elemental Analysis Using an Automated High-Precision Serial Sectioning System

The elemental composition and microscopic-level shape of inclusions inside industrial materials are considered important factors in fracture analytical studies. In this work, a three-dimensional (3D) microscopic elemental analysis system based on a serial sectioning technique was developed to observe the internal structure of such materials. This 3D elemental mapping system included an X-ray fluorescence analyzer and a high-precision milling machine. Control signals for the X-ray observation process were automatically sent from a data I/O system synchronized with the precision positioning on the milling machine. Composite specimens were used to confirm the resolution and the accuracy of 3D models generated from this system. Each of the two specimens was composed of three metal wires of 0.5 mm diameter braided into a single twisted wire that was placed inside a metal pipe; the pipe was then filled with either epoxy resin or Sn. The milling machine was used to create a mirror-finish cross-sectional surface on these specimens, and elemental analyses were performed. The twisted wire structure was clearly observed in the resulting 3D models. This system enables automated investigation of the 3D internal structure of materials as well as the identification of their elemental components.

Application of the Active Flexible Fixture to a Peg-in-hole Task

This paper describes the application of prototype of the AFLEF to a peg-in–hole task. This AFLEF is an active fixture and can fix any hole-work and position the fixed work at short range. We have combined the prototype of it and a 1-DOF inserting device with the RCC device into a new assembly system for such assembly task as a peg-in-hole task. However, there are two problems to realize this task. One is the “incomplete contact condition,” and another is the modification of location of a hole-work to the insertion point. In this paper, in order to solve the former, the AFLEF has been newly equipped with two touch sensors to judge the contact condition and it can modify the contact condition to the complete contact. Moreover, in order to solve the latter, we propose the modification method without any vision sensor. In order to confirm the effectiveness of our proposing modifications of the contact condition and the hole-work’s location, we have tried a peg-in-hole task with the assembly unit. As a result of this trial, although it took a little long time to finish a task, a task has been realized without failure.