Yutaka Kakehi

Vehicle body vibration control apparatus

A vehicle vibration control apparatus in which springs (3A) and (3B) for supporting the vehicle body place in juxtaposition with cylinders (4A) and (4B) for damping the vertical vibrations and a cylinder (4C) for damping the lateral vibrations. The detection signal from the vibration acceleration detectors (5A), (5B) and (5C) are compensated for by compensator circuits (6A), (6B) and (6C), and further amplified by amplifiers (7A), (7B) and (7C) thereby to control the internal pressure of the cylinders (4A), (4B) and (4C) by servo valves (8A), (8B) and (8C). The compensator circuit is comprised in a such manner that the transfer function thereof takes the form of the product of an integration response element, first order lead response elements and first order lag response elements, and therefore the response characteristic of the vehicle body on the vibration acceleration has no peak over a wide range of frequencies.

One-Dimensional Modeling for Magneto-Microwave Plasma Using the Monte Carlo Method

This study discusses modeling of a magneto-microwave plasma used in semiconductor manufacturing equipment such as etching reactors and chemical vapor deposition (CVD) reactors. A one-dimensional simulation program for magneto-microwave plasma was developed. This combines a Monte Carlo particle plasma model and an electromagnetic wave damping model. With the use of this simulation, a plasma production mechanism with electron cyclotron resonance and electromagnetic wave damping in a partially ionized gas can be analyzed. Typical results of the effect of gas pressure on the plasma distribution in plasma processing equipment are presented.

Noise Characteristics of Current Collector for High-Speed Railway Using Delta-Shaped Collector Head.

High-speed railway noise comes from vibration and aerodynamic noises. Rolling noise from rail and wheel vibration and aerodynamic noise generated under the car body can be minimized with noise barriers constructed along the rails. Thus. noise radiated from current collectors becomes the dominant noise source, and it must be controlled to reduce noise emission from high-speed railways. A pantograph cover is a useful and effective apparatus that reduces aerodynamic noise from a conventional pantograph when the operating speed does not exceed 300 km/h. At speeds over 300 km/h. however, the cover does not reduce aerodynamic noise enough to meet Japanese noise regulations, and its lift also becomes quite large. A new concept for a low-noise current collector has been developed. This current collector uses a delta-wing shape for the collector and has a pair of insulators on a hydraulic mechanism covered by a streamlined dome. The noise level of the new collector is expected to be 19 dB lower than that of the present pantograph.

Study on Low-Noise Current Collector for Super High-Speed Railways

For the purpose of reducing noise caused by current collector that are located on super high-speed railways, a new concept of low-noise current collectors has been developed. This new low-noise current collectors features are a delta-shaped collector head directly supported by a composite insulator. It also has a conductor for conducting power received from the current collector to an electric circuit. Both the conductor and insulator are supported by the two-step hydraulic mechanisms. The vertical height of those apparatus are controlled by using an active control system so as to maintain the predetermined contact force of the contact strip against the trolley-wire. As a result on bench tests, where a lift of 127 [N] was applied, the contact force decreased to 95% by detecting the force cylinder and varying the desired rising force. It was also confirmed that the limit tracking performance against roughness of the trolley-wire was 28 [mmp-p] at 2 [Hz] where the contact break ratio at 300 [km/h] was 20% by a pantograph test machine using an active control system.