Original Papers
9819
Title：Excitation Pulse-Pattern Signal Generator Centered Development of
Teaching Materials and Instruction System for Stepping Motor Control
Author：Hiroshi SHIRAHAMA
題目：パルス分配回路を中心としたステッピング・モ−タ制御学習用システムの開発
著者：白浜 博
Abstract
In a previous study, the author presented a VR-type linear stepping motor
and the control system for use in the instruction of stepping motor control.
These devices have been successfully used in our course for many years.
The paper describes the development of introductory level stepping motor
control teaching materials and an instruction system. The intention of
this effort was to introduce hardware technologies into Electromechanical
Technology Education. The purpose of this study was to present effective
teaching materials that facilitate the ability to design logic circuits
for stepping motor control drivers and to provide information about its
practical application. To accomplish this purpose, teaching materials such
as signal generators and other related devices were manufactured. A demonstration
was performed to confirm the effectiveness of the materials for educational
use. Demonstrations in our laboratory have proven that the materials and
instructional system are very effective in assisting students to understand
the logic design of stepping motor control drivers. Specifically, these
facilitated student comprehension of: (1) the logic performance and functions
of the circuit elements(ICs). (2) the logic design of driver circuits,
and (3) the behavioral differences between various stepping motors excitors.
The teaching material not only presented the fundamentals of logic design
methods but also practical experience in the form of wiring exercises,
wherein excitation pulse-pattern signal generator circuits were fabricated.
Therefore, through a series of exercises, the students were provided with
valuable assistance in transitioning from abstract design to physical realization.
Key words: stepping motor, hardware, pulse-pattern signal generators, teaching
materials
9822
Title：A Study of the Effectiveness of a Fluteless Tapping Tool for Cutting
Screw Threads
Author:Toshikazu YAMAMOTO, Ryoya MAKINO, Toru SEKIGUCHI
題目：ねじ切り加工における溝なしタップの有効性に関する研究
著者：山本利一，牧野亮哉，関口徹
Abstract
When junior high school students cut small female thread screw threads,
they usually use a tapping tool. As students are beginning to learn the
thread cutting procedure, the tapping tools are often broken. Though various
methods are used, when a tapping tool breaks off in the material it is
very difficult to remove the broken tapping tool from the product.
A trial lesson of thread cutting was conducted with students in order
to contrast the effectiveness of a fluteless tapping tool with a traditional
fluted tool, and to investigate ways to prevent tapping tool breakage.
The results clearly indicated that the fluteless tap significantly reduced
breakage and that small diameter screw threads could be efficiently cut.
In the case of large diameter thread cutting, the results indicated that
traditional fluted tapping tools are easy to use because they do not require
a large amount of torque. Further, they do not generate as much noise.
Key words: screw thread cutting, tapping tool with flute, fluteless tapping
tool, metal working
9827
Title:A Study of Screen Configurations for
VDT Text Reading in the Fundamentals of Information
Science and Technology Class
Author:Haruhisa YAMAGUCHI
題目：情報基礎におけるVDTテキストリーディングのための画面構成
著者：山口晴久
Abstract
The primary objective of the study was to
determine the optimal screen configuration
for first-year junior high school students
studying the fundamentals of information
science and technology. A study of easy-to-read
screen configurations to be used when reading
Japanese text in VDT was one of the most
important factors for the fundamentals of
information science and technology class.
I studied the reading performance of first-year
junior high school students as they read
textbooks while VDT conditions such as font
size, screen brightness, lettering style,
text and background colors were altered.
We also compared the performance of first-
year junior high school students with the
results of university students. The results
were as follows: 1) the optimal screen configuration
for first-year junior high school students
was somewhat different than that for university
students; 2) the optimal letter size for
first-year junior high school students was
determined to be 16 points which was larger
that what was required for the adults, 3)
ideally, each students should be able to
adjust his or her own screen configuration
in order to meet their individual needs.
However, if default screen conditions were
to be used in first-year junior high school
classrooms, the optimal background color
was white, the text black, the brightness-contrast
high, the letter style Minchoutai, with continuous
sentences in a 16 point font.
Key words: fundamentals of information science
and technology, VDT, screen configuration,
first-year junior high school student, readability
9902
Title：A Study on Lean Burn Using an L-Type
Spark-Ignition Engine
Author： Yasuo HARIGAYA, Tomomi KANNO and
Michiyoshi SUZUKI
題目：L型火花点火エンジンを用いた希薄燃焼に関する研究
著者：針谷安男，菅野知美，鈴木道義
Abstract
This paper describes a study on lean burn
using an L-type spark-ignition engine. The
fuel supply system was changed from the carburetion
system that was originally installed to an
electric fuel injection system. The ignition
system was also modified and the magneto
system was replaced with a high energy spark
type of capacitive discharge ignition (CDI).
We investigated the effects of lean burning
on engine performance, the coefficient of
variation for the indicated mean effective
pressure (COVpi), and combustion duration
. The parameters were engine speed and spark
ignition timing. The results were as follows:
a) the early combustion period θd and the primary combustion period θb increased as the mixture ratio increased;
b) under lean burn conditions, the indicated
thermal efficiency increased thereby conserving
energy; c) COVpi also increased as engine
speed, mixture ratio, and early combustion
period increased. An engine with a lean burning
mixture ration of 20 to 1 can be operated
in less than θd=30degCA conditions, with a wide range of
engine speeds.
Key words: spark-ignition engine, lean burn,
cycle variation, combustion duration, energy
conservation
Practical Papers
9809
Title：A Study on the Significance of the Casting and Surface Polishing
of a Bronze Mirror: A Cross-Discipline Learning Material for the Junior
High School
Author:Isamu NAKAMURA, Toshiaki HATA
題目：鋳造による「銅鏡」製作における鏡面仕上げとその意義について
−中学校の総合学習教材として−
著者：中村 勇，畑俊明
Abstract
In this paper we propose that the process of casting a bronze mirror should
be studied in the junior high school metal working class. The process of
casting of a bronze mirror incorporates the following distinguishing characteristics:
(a) the surface of the bronze mirror should be polished so that its shine
is equal to or better than a glass mirror; (b) the process of casting a
bronze mirror should be a continuous operation performed by the junior
high school students; and (c) the study of casting a bronze mirror should
be related to the history taught in social studies, especially that of
the Yayoi Era or tumulus period.
Students who have made a bronze mirror in which they are able see their
own reflection, attain an understanding of their cultural history not adequately
conveyed in text books. This experience has the potential to change the
junior high school students' view of history, inspiring them to think about
the social background of the Yayoi Era, a period from which artifacts have
recently been excavated. Beyond simply familiarizing students with the
working process, it encourages the study of history. Therefore, the process
of casting a bronze mirror becomes the kind of learning material that allows
junior high school students to synthesize knowledge.
Key words: bronze casting, bronze mirror, surface polishing, synthetic
learning material
9903
Title：Development of a Jig that can be used by Beginners to True the Edges
and Ends of a Board with a Plane
Author： Yasunori KAWAI and Riki SONOYAMA
題目：木材加工学習支援のためのこば･こぐちけずり治具の開発
著者：河合康則，園山 力
Abstract:
We developed a jig, for the beginner in woodworking, which can be easily
used for planing the edges and ends of a board. Junior high school students
were targeted in our examination of the jig's usefulness. In contrasting
planing with the jig and planing without the jig we found: (1) fewer students
gave up halfway; (2) planing time was reduced; (3) the number of times
that planing was required decreased; (4) the students' cuts were straighter
and the edges more perpendicular; (5) there were fewer rough areas in the
planed surface; and (6) the students' sense of accomplishment increased.
Key words: woodworking, plane, edges and ends of a board, jig